NurseReview.Org Pharmacology Bullet Review

Pharmacology Bullet Review Nursing Board Examination Review

Drug classification Nursing process applied to pharmacology Pharmacokinetics Pharmacodynamics

Diuretics Comparison Hypokalemia Ototoxicity Loop of Henle 3. Loop diuretics Hypovolemia & hypotension Glomerulus 5. Osmotic diuretic Hyperkalemia Distal tubule 4. Potassium sparing Hyperuricemia Hypokalemia Proximal tubule 2. Thiazide and thiazide like Acidosis Proximal tubule 1. Carbonic anhydrase inhibitor Special Side effect (s) Major site of action Diuretic class

Diuretics Comparison Hypercalcemia 3. Loop diuretics Increased ICP LITHIUM TOXICITY 5. Osmotic diuretic CHF taking digoxin 4. Potassium sparing Nephrolithiasis due to calcium stones Hypocalcemia 2. Thiazide and thiazide like Mountain sickness Meniere’s disease 1. Carbonic anhydrase inhibitor Special Uses Diuretic class

Thiazides
Prototype: Hydrochloro thiazide
1. Bendroflume thiazide
2. Ben thiazide
3. Chloro thiazide (Diuril)
4. Hydroflume thiazide
5. Methylclo thiazide
6. Trichlorme thiazide

Thiazide-like
1. Indapamide
2. Quinethazone
3. Metolazone
4. Chlorthalidone

Thiazides
Pharmacodynamics
These drugs BLOCK the chloride pump
This will keep the Chloride and Sodium in the distal tubule to be excreted into the urine
Potassium is also
flushed out!!

Thiazide
Special Pharmacodynamics: Side effects
Hypokalemia
DECREASED calcium excretion  hypercalcemia
DECREASED uric acid secretion  hyperuricemia
Hyperglycemia

Loop Diuretics
Prototype: Furosemide
1. Bumetanide
2. Ethacrynic acid
3. Torsemide

Loop Diuretics
Pharmacodynamics
High-ceiling diuretics
BLOCK the chloride pump in the ascending loop of Henle
SODIUM and CHLORIDE reabsorption is prevented
Potassium is also excreted together with Na and Cl

Loop Diuretics

Loop Diuretics
Special Pharmacodynamics: side-effects
Hypokalemia
Bicarbonate is lost in the urine
INCREASED calcium excretion  Hypocalcemia
Ototoxicity- due to the electrolyte imbalances

Potassium sparing diuretics
Prototype: Spironolactone
1. Amiloride
2. Triamterene

Pharmacodynamics
Spironolactone is an ALDOSTERONE antagonist
Triamterene and Amiloride BLOCK the potassium secretion in the distal tubule
Diuretic effect is achieved by the sodium loss to offset potassium retention

Pharmacokinetics: Side effects
HYPERkalemia!
Avoid high potassium foods:
Bananas
Potatoes
Spinach
Broccoli
Nuts
Prunes
Tomatoes
Oranges
Peaches

Osmotic Diuretics
Prototype: Mannitol
1. Glycerin
2. Isosorbide
3. Urea

Osmotic Diuretics
Pharmacodynamics
Mannitol is a sugar not well absorbed in the nephron  osmotic pull of water  diuresis

Osmotic Diuretics
Pharmacokinetics: side effects
Sudden hypovolemia
Important for the nurse to warm the solution to allow the crystals to DISSOLVE in the bottle!

Carbonic Anhydrase Inhibitors
Prototype: Acetazolamide
1. Methazolamide

Pharmacodynamics
Carbonic Anhydrase forms sodium bicarbonate
BLOCK of the enzyme results to slow movement of hydrogen and bicarbonate into the tubules
plus sodium is lost in the urine

Pharmacokinetics: side effects
Metabolic ACIDOSIS happens when bicarbonate is lost
Hypokalemia

The Nursing Process and the diuretics
ASSESSMENT
Assess the REASON why the drug is given:
______
______
______
______

ASSESSMENT
The nurse must elicit history of allergy to the drugs
Allergy to sulfonamides may contraindicate the use of thiazides
Assess fluid and electrolyte balance
Assess other conditions like gout, diabetes, pregnancy and lactation

ASSESSMENT
Physical assessment
Vital signs
Special electrolyte and laboratory examination
Assess symptom of body weakness which may indicate hypokalemia

Nursing Diagnosis
Fluid volume deficit related to diuretic effect
Alteration in urinary pattern
Potential for injury (ototoxocity, hypotension)
Knowledge deficit

IMPLEMENTATION
Administer IV drug slowly
Safety precaution for dizziness/hypotension
Provide potassium RICH foods for most diuretics, with the exception of spironolactone
Provide skin care, oral care and urinary care

IMPLEMENTATION
Monitor DAILY WEIGHT- to evaluate the effectiveness of the therapy
Monitor urine output, cardiac rhythm. Serum electrolytes
ADMINISTER in the MORNING!
Administer with FOOD!

EVALUATION: for effectiveness of therapy
Weight loss
Increased urine output
Resolution of edema
Decreased congestion
Normal BP

CNS DRUGS

The ANXIOLYTICS AND HYPNOTICS
These drugs are used to change the individual’s responses to the environment.

The medications that can prevent the feelings of tension and fear are called ANXIOLYTICS.
Anti-anxiety drugs

The drugs that can calm individuals making them unaware of the environment are called SEDATIVES.

The drugs that can induce sleep are called HYPNOTICS.

The drugs in this class are the
BENZODIAZEPINES
BARBITURATES

Use of The Drugs
Clinical indications for the use of the
anxiolytics, sedatives and hypnotics
1. Prevention of anxiety
2. Formation of sedative state
3. Induction of sleep

The BENZODIAZEPINES
The benzodiazepines are the most frequently used anxiolytic drugs.
These agents prevent anxiety states without causing much sedation, with less physical dependence than other agents.

The BENZODIAZEPINES
The following are the benzodiazepines
Alprazolam (Xanax)
Chlordiazepoxide (Librium )
clonazepam
clorazepate
Diazepam (Valium)
estazolam
flurazepam
lorazepam
midazolam
oxazepam
quazepam
temazepam
triazolam

The BENZODIAZEPINES Special uses Panic attack Alprazolam (Xanax) Alcohol withdrawal Chlordiazepoxide (Librium) Status epilepticus Diazepam (Valium)

The BENZODIAZEPINES
The Mechanism of Action of the Benzodiazepines
These agents act on the Limbic system and the RAS (reticular activating system) to make the GABA ( Gamma-aminobutyric acid) more effective causing interference with neuron firing.

The BENZODIAZEPINES
The Mechanism of Action of the Benzodiazepines
The GABA is an inhibitory neurotransmitter.
This will result to an anxiolytic effect at lower doses than required for sedation/hypnosis.

The BENZODIAZEPINES
These agents are indicated for the treatment of
anxiety disorders
alcohol withdrawal
hyperexcitability, and agitation
pre-operative relief of anxiety and tension and in induction of balanced anesthesia.

The BENZODIAZEPINES
Pharmacodynamics: The adverse effects
CNS effects= sedation, drowsiness, depression, lethargy, blurred vision
GIT= dry mouth, constipation , nausea, vomiting
CVS= Hypotension or hypertension, arrhythmias, palpitations, and respiratory difficulties.
Hematologic= blood dyscrasias and anemia
GU= urinary retention, hesitancy, loss of libido and sexual functions changes.

The BENZODIAZEPINES
Nursing Considerations:
Maintain patients on bed for at least 3 hours after drug administration.
Instruct to avoid hazardous activities like driving and machine operation.
Instruct to avoid consuming ALCOHOL while taking the drug .

The BENZODIAZEPINES
Provide comfort measures to help patients tolerate drug effects-
instruct to urinate before taking drug
give high fiber foods
use side-rails and assistance with ambulation.
Have available FLUMAZENIL as an antidote for benzodiazepine overdose.

The BARBITURATES
These are also anxiolytics and hypnotics with a greater likelihood of producing sedation, with increase risk of addiction and dependence.

The BARBITURATES
The following are the barbiturates
amobarbital
aprobarbital
butabarbital
mephobarbital
pentobarbital
Phenobarbital
secobarbital

The BARBITURATES
The Mechanism of Action of the Barbiturates
They depress the motor output from the brain.
The results of their MOA are sedation, hypnosis and anesthesia, and if extreme, coma.

The BARBITURATES
Clinical indications of the Barbiturates
Relief of anxiety manifestations
For sedation
For patients with insomnia
For pre-anesthesia
seizures/epilepsy
The rapid acting barbiturates are also used for the treatment of acute manic reactions and status epilepticus

The BARBITURATES
Pharmacodynamics: The Adverse effects
CNS= CNS depression , somnolence , vertigo, lethargy, ataxia, paradoxical excitement, anxiety and hallucinations.
GIT= nausea, vomiting, constipation/diarrhea and epigastric pain
CVS= bradycardia, Hypotension and syncope.
Respi= serious hypoventilation, respiratory depression and laryngospasms
Others= hypersensitivity and Stevens-Johnson syndrome.

The BARBITURATES
Nursing Considerations
Provide stand-by life support facilities in cases of severe respiratory depression or hypersensitivity reaction.
Taper the drug gradually after long-term therapy to avoid withdrawal syndrome.
Provide comfort measures including small frequent meals, access to bathroom facilities, high-fiber foods, environmental control, safety precaution and skin care.

The CNS stimulants
These are drugs used to treat certain disorders
exogenous obesity
attention-deficit hyperactivity disorders (ADHD)
narcolepsy

The CNS stimulants
What is unusual is the ability of the CNS stimulants to CALM hyperactive children, which allows them to focus on one activity for a longer period.

The CNS stimulants
The following are the CNS stimulants:
1. Methylphenidate (Ritalin)= most commonly used for ADHD
2. Dextroamphetamine= a CNS stimulant that is used for short tem therapy for obesity.
3. Modafinil= used for narcolepsy
4. Pemoline= used for ADHD

The CNS stimulants
The Mechanism of Action
These agents act as to stimulate the cortical and reticular activating system (RAS) of the brain.
This is by releasing neurotransmitters from the nerve cells leading to increased stimulation of the post-synaptic neurons.

The CNS stimulants
The paradoxical effect of calming hyperexcitability through CNS stimulation seen in ADHD is believed to be related to the increased stimulation of an IMMATURE Reticular Activating System leading to the ability to be more selective in response to incoming stimuli.

The CNS stimulants
Pharmacodynamics: Adverse effects of the CNS stimulants
CNS= nervousness, insomnia , dizziness, headache, and blurred vision
GIT= anorexia , nausea and weight loss
CVS= hypertension, tachycardia arrhythmias, and angina
Others= rashes, physical/psychological dependence.

The CNS stimulants
Implementation
The nurse must ensure that the drug is only given to the indicated conditions
Administer the drug before 6 pm to reduce the effect of insomnia
BEST given AFTER meals to prevent the effect of anorexia
Consult with school personnel to monitor the patient under therapy
Provide safety measures such as side-rails and assisted ambulation

The CNS stimulants
Evaluation
Evaluate the effectiveness of the drug:
Calming effect in the patient with ADHD
Alertness for patients with narcolepsy

The Anti-epileptics
These agents, also called anticonvulsants, are used to treat epileptic conditions.
Hydantoins, Barbiturates, benzodiazepines, Succinimides and many others are given to a specific type of seizure.

Anti-epileptics
Agents for treating TONIC-CLONIC SEIZURES
1. Hydantoins
Phenytoin
Ethotoin
Fosphenytoin
Mephenytoin
2. Benzodiazepines
Diazepam
Clonazepam
Clorazepate
3. Barbiturates
Phenobarbital

Anti-epileptics
Agents for treating ABSENCE SEIZURES
1. Succinimides
a. Ethosuximide
b. Methsuximide
c. Phensuximide
2. Valproic Acid
3. Zosinamide

Anti-epileptics
Agents for treating Partial FOCAL SEIZURES
1. Carbamazepine
2. Gabapentin
3.Lamotrigine
4. Tiagabine
5. Topiramate

The hydantoins
These agents are utilized for general seizures because they can depress the central nervous system.
They affect the entire brain and reduce the chance of sudden electrical outburst that causes seizures.
These agents generally are less sedating than other anti-epileptics .

The hydantoins
Mechanism of Action of the Hydantoins
These agents STABILIZE the nerve cell membrane throughout the brain reducing and limiting the excitability and conduction through nerve pathways.

The hydantoins
Clinical Indications of the hydantoins
Tonic-clonic seizures
Status epilepticus
For the prevention of seizures in neurosurgery
For muscle relaxation.

The hydantoins
Contraindications and Precautions
Hydantoins are NOT given to pregnant patient because it can cause fetal hydantoin syndrome .

The hydantoins
Pharmacodynamics: Adverse effects of the Hydantoins
CNS effects- depression, confusion, drowsiness, lethargy, fatigue
GIT- GI upset, constipation, dry mouth , GINGIVAL HYPERPLASIA , severe liver toxicity which are all related to cellular toxicity.
SKIN- hirsutism and coarsening of the facial skin
Bone Marrow depression

The hydantoins
Implementation
Administer the drug with food to alleviate GI irritation
Discontinue the drug at any sign of hypersensitivity reaction, severe liver dysfunction and severe skin rashes.
Provide meticulous mouth oral care
Rule out pregnancy and advise women to use contraceptive measures to prevent pregnancy.

GIT DRUGS

Drugs affecting GI secretions
There are five types of drugs that affect gastric acid secretions and are useful for the treatment of peptic ulcer.
Histamine (H2) receptor antagonist/blockers
Antacids
Proton pump inhibitors
Mucosal protectants
Prostaglandin analogs

Drugs affecting secretions: anti ulcer Misoprostol Prostaglandin analog Sucralfate Mucosal protectants Omeprazole Proton pump inhibitors AlOH and MgOH Antacids Cimetidine Histamine (H2) receptor antagonist/blockers Prototype Anti-ulcer drugs

General indication of the drugs affecting gastric acid secretion
Peptic ulcer
Gastritis
Patient on NPO to prevent stress ulcer

General time of administration of the drugs affecting gastric acid secretion Misoprostol WITH MEALS Prostaglandin analog Sucralfate BEFORE MEALS Mucosal protectants Omeprazole BEFORE MEALS Proton pump inhibitors AlOH and MgOH Usually after meals Antacids Cimetidine With FOOD or ONE hour after ANTACID Histamine (H2) receptor antagonist/blockers Prototype Best time to give Anti-ulcer drugs

Pharmacology of Anti-ulcer drugs Inhibit Proton Pump in parietal cell decreasing secretion and acidity Proton pump inhibitors- “ Prazoles” Omeprazole, pantoprazole Block Histamine receptor causing decreased secretion and acidity H2-Blockers- “ tidine ” Cimetidine , Ranitidine Neutralize Gastric ACIDITY Antacids- AlOH, MgOH Mechanism of Action Drug

Pharmacology of Anti-ulcer drugs Prostaglandin Analogue, causes secretion of MUCUS Misoprostol (Cytotec) Coats the mucosal lining Sucralfate (Carafate) Blocks VAGUS nerve, decreases secretion Anti-cholinergic- Prophanteline Bromide Mechanism of Action Drug

Pharmacodynamics
Histamine (H2) receptor blockers
These drugs BLOCK the release of hydrochloric acid in the stomach in response to gastrin

Antacids
These drugs interact with the gastric acids at the chemical level to neutralize them

Proton pump inhibitors
These drugs suppress the secretion of hydrochloric acid into the lumen of the stomach

Mucosal protectants
These are agents that coat any injured area in the stomach to prevent further injury from acid

Prostaglandin analogs
These are agents that inhibit the secretion of gastrin and
increase the secretion of mucus lining of the stomach, providing a buffer.

The H2 Blockers- “tidines”
Prototype: Cimetidine
1. Ranitidine
2. Famotidine
3. Nizatidine

Pharmacodynamics: Drug Action
The H2 blockers are antagonists at the receptors in the parietal cells of the stomach.
The blockage results to inhibition of the hormone gastrin.
There will be decreased production of gastric acid from the parietal cells.
Also, the chief cells will secrete less pepsinogen.

Therapeutic use of the H2 blockers
Short-term treatment of active duodenal ulcer or benign gastric ulcer
Treatment of hypersecretory conditions like the Zollinger-Ellison syndrome
Prevention of stress-induced ulcers and acute GI bleeding
Treatment of erosive GERD (reflux disease)
Relief of Symptoms of heart burn and acid indigestion

Precautions and Contraindications
Any known allergy is a clear contraindication to the use of the agents. Conditions such as pregnancy, lactation, renal dysfunction and hepatic dysfunction should warrant cautious use.
Nizatidine can be used in hepatic dysfunction.

Pharmocodynamics- Side effects and adverse effects
GIT= diarrhea or constipation
CNS= Dizziness, headache, drowsiness, confusion and hallucinations
Cardio= arrhythmias, HYPOTENSION (related to H2 receptor blockage in the heart)
Cimetidine= TREMORS, Gynecomastia and impotence in males

Drug-drug Interactions
Cimetidine, Famotidine, Ranitidine are metabolized in the liver- they can cause slowing of excretion of other drugs leading to their increased concentration.

Drug-drug Interactions
These drugs can interact with CIMETIDINE anticoagulants, phenytoin, alcohol, antidepressants.

Nursing considerations:
Administer the drug WITH meals at BEDTIME to ensure therapeutic level
One hour after Antacids
Stress the importance of the continued use for the length of time prescribed

Monitor the cardiovascular status especially if the drugs are given IV
Warn patient of the potential problems of increased drug concentration if the H2 blockers are used with other drugs or OTC drugs. Advise consultation first!

Provide comfort measures like analgesics for headache, assistance with ambulation and safety measures
Warn the patients taking cimetidine that drowsiness may pose a hazard if driving or operating delicate machines.

Provide health teaching as to the dose, frequency, comfort measures to initiate when side-effects are intolerable
Evaluate the effectiveness:
Relief of symptoms of ulcer, heart burn and GERD

The Antacids
These are drugs or inorganic chemicals that have been used for years to neutralize acid in the stomach. The following are the common antacids that can be bought OTC:
Aluminum salts (hydroxide)
Calcium salts (carbonate)
Magnesium salts (milk of magnesia)
Sodium bicarbonate
Magaldrate (aluminum and magnesium combination)

The Antacids
Pharmacodynamics: drug action
These agents act to neutralize the acidic pH in the stomach.
They do not affect the rate of gastric acid secretion.

The Antacids
The administration of antacid may cause an acid rebound.
Neutralizing the stomach content to an alkaline level stimulates gastrin production to cause an increase in acid production and return the stomach to its normal acidic state.

The Antacids
Therapeutic Indications
Symptomatic relief of upset stomach associated with hyperacidity
Hyperacidic conditions like peptic ulcer, gastritis, esophagitis and hiatal hernia
Special use of AMPHOGEL (aluminum hydroxide): to BIND phosphate

The Antacids
Precautions of Antacid Use
Known allergy is a clear contraindication. Caution should be instituted if used in electrolyte imbalances, GI obstruction and renal dysfunction.
Sodium bicarbonate is rarely used because of potential systemic absorption

The Antacids
Pharmacokinetics
These agents are taken orally and act locally in the stomach

The Antacids
Pharmacodynamics: Effects of drugs
GIT= rebound acidity; alkalosis may occur.
Calcium salts may lead to hypercalcemia
Magnesium salts can cause DIARRHEA
Aluminum salts may cause CONSTIPATION and hypophosphatemia by binding with phosphates in the GIT.
2. Fluid retention due to the high sodium content of the antacids.

The Antacids
Administer the antacids apart from any other medications by ONE hour before or TWO hours after- to ensure adequate absorption of the other medications
Tell the patient to CHEW the tablet thoroughly before swallowing. Follow it with one glass of water
Regularly monitor for manifestations of acid-base imbalances as well as electrolyte imbalances

The Antacids
Provide comfort measures to alleviate constipation associated with aluminum and diarrhea associated with magnesium salts.
Monitor for the side-effects, effectiveness of the comfort measures, patient’s response to the medication and the effectiveness of the health teachings

The Antacids
Evaluate for effectiveness:
Decreased symptoms of ulcer and pyrosis
Decreased Phosphate level (amphogel)

The PPI
These are the newer agents for ulcer treatment
The “prazoles”
Prototype: Ome prazole
Laniso prazole
Esome prazole
Panto prazole

The PPI
They act at specific secretory surface receptors to prevent the final step of acid production and thus decrease the level of acid in the stomach.
The “pump” in the parietal cell is the H-K ATPase enzyme system on the secretory surface of the gastric parietal cells

The PPI
Clinical use of the PPIs
Short-term treatment of active duodenal ulcers, GERD, erosive esophagitis and benign gastric ulcer.
Long-term- maintenance therapy for healing of erosive disorders.

The PPI
Clinical use of the PPIs.
Precautions with the use of the PPIs
Known allergy is a clear contraindication. Caution if patient is pregnant

The PPI
Pharmacodynamics: Adverse effects
CNS- dizziness , headache, asthenia (loss of strength), vertigo , insomnia, apathy
GIT- diarrhea, abdominal pain, nausea, vomiting, dry mouth and tongue atrophy
Respi- cough, stuffy nose, hoarseness and epistaxis.

The PPI
Administer the drug BEFORE meals. Ensure that patient does not open, chew or crush the drug.
Provide safety measures if CNS dysfunction happens.
Arrange for a medical follow-up if symptoms are NOT resolved after 4-8 weeks of therapy.

The PPI
Provide health teaching as to drug name, dosages and frequency, safety measures to handle common problems.
Monitor patient response to the drug, the effectiveness of the teaching plan and the measures to employ

The PPI
Evaluate for effectiveness of the drug
Healing of peptic ulcer
Decreased symptoms of ulcer

The Mucosal Protectant
Sucralfate
This is given to protect the eroded ulcer sites in the GIT from further damage by acid and digestive enzymes

Sucralfate
Pharmacodynamics: Action of drug
It forms an ulcer-adherent complex at duodenal ulcer sites, protecting the sites against acid, pepsin and bile.
This action prevents further breakdown of proteins in the area and promotes healing.

Sucralfate
Clinical use of sucralfate
Short and long term management of duodenal ulcer.
NSAIDs induced gastritis
Prevention of stress ulcer
Treatment of oral and esophageal ulcers due to radiation, chemotherapy or sclerotherapy.

Sucralfate
Precautions on the use of Sucralfate
This agent should NOT be given to any person with known allergy to the drug, and to those patients with renal failure/dialysis because of build-up of aluminum may occur if used with aluminum containing products.

Pharmacodynamics: Side-effects & adverse reactions
Primarily GIT= CONSTIPATION, occasionally diarrhea, nausea, indigestion, gastric discomfort, and dry mouth may also occur
CNS= dizziness, drowsiness, vertigo
Others= rash and back pain

Drug-drug interactions
If used with aluminum salts= high risk of accumulation of aluminum and toxicity .
If used with phenytoin, fluoroquinolones and penicillamines- decreased levels of these drugs when taken with sucralfate

Administer drug ON AN EMPTY stomach , 1 hour before meals , or 2 hour after meals and at BEDTIME
Monitor for side-effects like constipation and GI upset
Encourage intake of high-fiber foods and increased fluid intake
Administer antacids BETWEEN doses of sucralfate, NOT WITHIN 30 minutes of sucralfate dose

Provide comfort measures if CNS effects occur
Monitor patient response to the drug, the effectiveness of the teaching plan and the measures employed

Evaluate effectiveness of therapy
Healing of ulcer
No formation of ulcer

Prostaglandin analogue
Misoprostol
This agent is a synthetic prostaglandin E1 analog that is employed to protect the lining of the mucosa of the stomach

Misoprostol: Pharmacodynamics
Being a prostaglandin analog, it inhibits gastric acid secretion to some degree
It INCREASES mucus production in the stomach lining.

Misoprostol: Clinical use
NSAIDs-induced gastric ulcers
Duodenal ulcers unresponsive to H2 antagonists.

Precautions of Misoprostol Use
This drug is CONTRAINDICATED during pregnancy because it is an abortifacient.
Women should be advised to have a negative pregnancy test within 2 weeks of beginning therapy and should begin the drug on the second or third day of the next menstrual cycle.
They should be instructed in the use of contraceptives during therapy.

Pharmacodynamic effects: drug reactions
GIT= Nausea, diarrhea, abdominal pain, flatulence, vomiting, dyspepsia
GU effects= miscarriages, excessive uterine CRAMPING and bleeding , spotting, hypermenorrhea and menstrual disorders.

Administer to patients at risk for NSAIDs-induced ulcers during the full course of NSAIDs therapy
Administer four times daily with meals and at bedtime
Obtain pregnancy test within 2 weeks of beginning therapy. Begin the therapy on second or third day of menstrual period to ensure that the woman is not pregnant

Provide patient with both written and oral information regarding the associated risks of pregnancy
Monitor patient response to the drug, the effectiveness of the teaching plan and the measures to employ

laxatives

Laxatives Lubricating the intestinal material to promote passage through the GIT Docusate Lubricants Increased fluid content of the fecal material causing stimulation of the local reflex Lactulose Mechanical (bulk) stimulants Direct stimulation of the GIT nerves Irritant laxatives Bisacodyl (Dulcolax) Chemical stimulants Action Prototype Type

Laxatives
Generally used to INCREASE the passage of the colonic contents
The general classifications is as follows:
1. Chemical stimulants
2. Mechanical stimulants
3. Lubricants

Therapeutic Indications of the Laxatives
SHORT term relief of Constipation
Prevention of straining in conditions like CHF, post-MI, post partum, post-op
Preparation for diagnostic examination
Removal of poison or toxins
Adjunct in anti-helminthic therapy

Contraindications in Laxative use
ACUTE abdominal disorders
Appendicitis
Diverticulitis
Ulcerative colitis

Chemical Stimulant Cathartics
Prototype: Bisacodyl
Irritant laxatives:
1. Castor oil
2. Senna
3. Cascara
4. Phenolphthalein

Chemical Stimulant Cathartics
Pharmacodynamics
These agents DIRECTLY stimulate the nerve plexus in the intestinal wall
The result is INCREASED movement or motility of the colon

Mechanical Stimulant Cathartics
Prototype: LACTULOSE (Cephulac)
Bulk-forming laxatives
1. Magnesium (citrate, hydroxide, sulfate)
2. Psyllium
3. Polycarbophil

Mechanical Stimulant Cathartics
Pharmacodynamics
These agents are rapid-acting laxatives that INCREASE the GI motility by
Increasing the fluids in the colonic material
Stimulating the local stretch receptors
Activating local defection reflex

Lubricants
Prototype: Docusate
1. Glycerin
2. Mineral oil

Lubricants
Pharmacodynamics
Docusate increases the admixture of fat and water producing a softer stool
Glycerin
Mineral oil forms a slippery coat on the colonic contents

Pharmacokinetics: Common Side-effects of the Laxatives
Diarrhea
Abdominal cramping
Nausea
Fluid and electrolyte imbalance
Sympathetic reactions- sweating, palpitations, flushing and fainting
CATHARTIC dependence

The Nursing Process and Laxative
ASSESSMENT
Nursing History- elicit allergy to any laxatives, elicit history of conditions like diverticulitis and ulcerative colitis
Physical Examination- abdominal assessment
Laboratory Test: fecalysis, electrolyte levels

NURSING DIAGNOSIS
Alteration in bowel pattern
Alteration in comfort: pain
Knowledge deficit

IMPLEMENTATION
Emphasize that it is use on a SHORT term basis
Provide comfort and safety measures like ready access to the bathroom, side-rails
Administer with a full glass of water

IMPLEMENTATION
4. Encourage fluid intake, high fiber diet and daily exercise
5. DO NOT administer if acute abdominal condition like appendicitis is present
6. Advise to change position slowly an avoid hazardous activities because of potential dizziness

EVALUATION of drug effectiveness
Evaluate relief of GI symptoms, absence of staining and increased evacuation of GI tract
For Lactulose: decreased ammonia

The Anti-diarrheals
These are agents used to calm the irritation of the GIT for the symptomatic relief of diarrhea
General Classifications
1. Local anti-motility
2. Local reflex inhibition
3. Central action on the CNS

The Anti-diarrheals Stops GIT spasm by CNS action Opium derivatives (paregoric) Central acting agent Directly inhibits the intestinal muscle activity to SLOW peristalsis Loperamide Local anti-motility Locally coats the lining of the GIT to soothe irritation that may stimulate the reflex Bismuth subsalicylate Local reflex inhibitor Action Prototype Type

Clinical Indications of drug use
Relief of symptoms of acute and chronic diarrhea
Reduction of fecal volume discharges from ileostomies
Prevention and treatment of traveler's diarrhea

Contraindications of anti-diarrheal Use
Poisoning
Drug allergy
GI obstruction
Acute abdominal conditions

Pharmacokinetics: Side effects
Constipation
Nausea, vomiting
Abdominal distention and discomfort
TOXIC MEGACOLON

Nursing process and anti-diarrheals
ASSESSMENT
Nursing History – Elicit history of drug allergy, conditions like poisoning, GI obstruction and acute abdominal conditions
Physical Examination- Abdominal examination
Laboratory test- electrolyte levels

NURSING DIAGNOSIS
Alteration in bowel pattern

IMPLEMENTATION
Monitor patient response within 48 hours. Discontinue drug use if no effect
Provide comfort measures for pain
Provide teaching

EVALUATION
Monitor effectiveness of drug- RELIEF of diarrhea
Monitor adverse effects, effectiveness of pain measures and effectiveness of teaching plan

Emetics and Anti-emetics
Emetic Agent
Syrup of Ipecac
Anti-emetics
1. Phenothiazines
2. Non-phenothiazines
3. Anticholinergics/Antihistamines
4. Serotonin receptor Blockers
5. Miscellaneous

EMETIC
Prototype: Ipecac Syrup

EMETIC
Pharmacodynamics
Ipecac syrup irritates the GI mucosa locally, resulting to stimulation of the vomiting center
It acts within 20 minutes

EMETIC
Clinical Use of ipecac
To induce vomiting as a treatment for drug overdose and certain poisonings

EMETIC
Contraindications of Ipecac use
Ingestion of CORROSIVE chemicals
Ingestion of petroleum products
Unconscious and convulsing patient

EMETIC
Pharmacokinetics: side effects of Ipecac
Nausea
Diarrhea
GI upset
Mild CNS depression
CARDIOTOXICITY if large amounts are absorbed in the body

Nursing process and the EMETIC
ASSESSMENT
Nursing History- elicit the exact nature of poisoning
Physical Examination- CNS status and abdominal exam

IMPLEMENTATION
Administer to conscious patient only
Administer ipecac as soon as possible
Administer with a large amount of water
Vomiting should occur within 20 minutes of the first dose. Repeat the dose and expect vomiting to occur with 20 minutes

IMPLEMENTATION
5. Provide comfort measures like ready access to bathroom, assistance with ambulation
6. Offer support

EVALUATION
Evaluate patient response within 20 minutes of drug ingestion
Monitor for adverse effects
Evaluate effectiveness of comfort measures and teaching plan

ANTI-EMETICS
These are agents used to manage nausea and vomiting
They act either locally or centrally

ANTIEMETICS Dronabinol, hydroxyzine Miscellaneous “ setron”- dolasetron Serotonin Receptor blockers Meclizine, buclizine Anticholinergics and Antihistaminics Metoclopramide Non-phenothiazines Prochlorperazine, promethazine Phenothiazines Common examples Anti-emetic types

ANTIEMETICS Act in the CNS , either in the medulla or in the cortex Miscellaneous Centrally and locally inhibits the serotonin receptors Serotonin receptor blockers Block the transmission of the impulses to the medulla Anticholinergics Reduces the responsiveness of the nerve cell in the medulla Non-phenothiazine Centrally block the vomiting center in the medulla Phenothiazines Pharmacodynamics Types

ANTIEMETICS N/V associated with chemotherapy Miscellaneous N/V associated with chemotherapy Serotonin-receptor Blockers N/V associated with motion sickness Anticholinergics N/V associated with chemical stimulation Non-phenothiazine N/V associated with anesthesia, intractable hiccups Phenothiazines Clinical Use Types

ANTIEMETICS
Contraindications
1. Severe CNS depression
2. Severe liver dysfunction

ANTIEMETICS
Pharmacokinetics: Side-effects
1. PHOTHOSENSITIVITY
2. Drowsiness, dizziness, weakness and tremors and DEHYDRATON
3. Phenothiazines= autonomic anti-cholinergic effects like dry mouth, nasal congestion and urinary retention

Nursing Process and the ANTIEMETICS
ASSESSMENT
Nursing History- elicit allergy, impaired hepatic function and CNS depression
Physical Examination- CNS status and abdominal examination
Laboratory test- Liver function studies

NURSING DIAGNOSIS
High risk for injury
Knowledge deficit

IMPLEMENTATION
Assess patient’s intake of other drugs that may cause dangerous drug interaction
Emphasize that this is given on a short term basis

IMPLEMENTATION
3. Provide comfort and safety measures
Advise to change position slowly
Avoid hazardous activities
Provide mouth care and ice chips
Monitor for dehydration and offer fluids if it occurs

IMPLEMENTATION
4. Protect from sun exposure
Sunscreens
Protective covering
5. Provide health teaching

EVALUATION
1. Monitor for the drug effectiveness
Relief of nausea and vomiting
2. Monitor for adverse effects
3. Evaluate effectiveness of comfort measures and teaching plan

Pharmacology of the Selected Endocrine Drugs Nursing Review

Endocrine Medications
Anti-diuretic hormones
Enhance re-absorption of water in the kidneys
Used in DI
1. Desmopressin and Lypressin intranasally
2. Pitressin IM

Endocrine Medications
Anti-diuretic hormones
SIDE-effects
Flushing and headache
Water intoxication

Thyroid Medications
Thyroid hormones
These products are used to treat the manifestations of hypothyroidism
Replace hormonal deficit in the treatment of HYPOTHYROIDSM

Thyroid Medications
Thyroid hormones
Levothyroxine (Synthroid)
Liothyroxine (Cytomel)
Thyroid dessicated
Liotrix (Thyrolar)

Thyroid Medications
Thyroid hormones: Actions
Increase the metabolic rate
Increase O2 consumption
Increase HR, RR, BP

Thyroid Medications
Thyroid hormones
Side-effects
Nausea and Vomiting
Signs of increased metabolism= tachycardia, hypertension, cardiac arrhythmias, anxiety, headache

Thyroid Medications
Thyroid hormones : Nursing responsibility
1. Monitor weight, VS
2. Instruct client to take daily medication the same time each morning WITHOUT FOOD
Monitor blood tests to check the activity of thyroid

Thyroid Medications
Thyroid hormones: Nursing responsibility
3. Advise to report palpitation, tachycardia, and chest pain
4. Instruct to avoid foods that inhibit thyroid secretions like cabbage, spinach and radishes

ANTI-Thyroid Medications
ANTI-THYROID medications
The thyroid becomes oversaturated with iodine and stop producing thyroid hormone

Drugs used to BLOCK the thyroid hormones and treat hyperthyroidism
Inhibit the synthesis of thyroid hormones

1. Methimazole (Tapazole)
2. PTU (prophylthiouracil)
3. Iodine solution- SSKI and Lugol’s solution

Side-effects of thionamides
N/V, drowsiness, lethargy, bradycardia, skin rash
GI complaints
AGRANULOCYTOSIS
Most important to monitor

Side-effects of Iodine solutions
Most common adverse effects is HYPOTHYROIDISM
Iodism= metallic taste, burning in the mouth, sore teeth and gums, diarrhea, stomach upset

Nursing responsibilities
1. Monitor VS, T3 and T4, weight
2. The medications WITH MEALS to avoid gastric upset

ANTI-THYROID medications Nursing responsibilities
3. Instruct to report SORE THROAT or unexplained FEVER
4. Monitor for signs of hypothyroidism.
Instruct not to stop abrupt medication

Lugol’s Solution
Used to decrease the vascularity of the thyroid (in preparation for thyroid surgery)
T3 and T4 production diminishes
Given per orem, can be diluted with juice
Use straw to decrease staining
Monitor iodism (metallic taste, burning in mouth)

STEROIDS
Replaces the steroids in the body
Interfere with the release of inflammatory factors and immune responses

STEROIDS
Cortisol, cortisone, betamethasone, and hydrocortisone
Dexamethasone= long acting

STEROIDS
These drugs enter the cells and bind to receptors
They inhibit the enzyme phospholipase

STEROIDS
Corticosteroids are used topically and locally to achieve the desired anti-inflammatory effects at a particular site

STEROIDS Use for the treatment of immune-related diseases, control of asthma and allergic symptoms Other steroids Use to induce the formation of lung surfactant Dexamethasone Clinical use Steroid

STEROIDS
Side-effects
HYPERglycemia
Increased susceptibility to infection (immunosuppression)
Hypokalemia
Edema and Hypertension
Peptic ulceration

STEROIDS
Side-effects
If high doses- osteoporosis, growth retardation, peptic ulcer, hypertension, cataract , mood changes, hirsutism, and fragile skin

STEROIDS
1. Monitor VS, electrolytes, glucose
2. Monitor weight edema and I/O. Encourage Potassium supplements

STEROIDS
3. Protect patient from infection
4. Handle patient gently
5. Instruct to take meds WITH MEALS to prevent gastric ulcer formation

STEROIDS
6. Caution the patient NOT to abruptly stop the drug
7. Drug is tapered to allow the adrenal gland to secrete endogenous hormones

STEROIDS
Evaluation:
The drugs are effective if there is:
Relief of signs and symptoms of inflammation
Return of adrenal function to normal

Cardiovascular drugs

The cardiac glycosides
These are agents extracted from the foxglove plant. They are available in oral and parenteral preparations. The following are the cardiac glycosides:
Digoxin (Lanoxin)
Digitoxin (Crystodigin)
Ouabain

Pharmacodynamics: the Mechanism of action
They increase the level of CALCIUM inside the cell by inhibiting the Sodium-Potassium pump.
More calcium will accumulate inside the cell during cellular depolarization.

Positive inotropic Effect- the myocardium will contract forcefully
Increased cardiac output
Increased blood flow to the body organs like the kidney and liver
Negative chronotropic effect- the heart rate is slowed due to decreased rate of cellular repolarization
Bradycardia
Decreased conduction velocity through the AV node

Clinical Use of the cardiac glycosides
Treatment of congestive heart failure
Treatment of dysrhythmias like atrial flutter, atrial fibrillation and paroxysmal atrial tachycardia

Contraindications and Precautions
Contraindicated in the presence of allergy to any cardiac glycoside.
They are NOT given to patients with ventricular dysrhythmias, heart block or sick sinus syndrome, aortic stenosis, acute MI, electrolyte imbalances ( HYPOKALEMIA, HYPOMAGNESEMIA and HYPERCALCEMIA ) and renal failure (may cause accumulation of drug)

Pharmacodynamics: the Adverse Effects of the Cardiac glycosides
CNS- Headache, weakness , seizures and drowsiness
CVS- arrhythmias
If digitalis toxicity is developing- the nurse must assess the following adverse effects: Anorexia, nausea and vomiting, visual changes- YELLOW halo around an object, and palpitations or very slow heart rate

Remember= NAVDA and hypokalemia

Drug-Drug Interactions
If taken with potassium-losing diuretics like furosemide- can INCREASE the risk of toxicity and arrhythmias. Potassium replacement must be given.

Implementation
Administer the initial rapid digitalization and loading dose as ordered intravenously
Monitor the APICAL pulse rate for ONE full minute before administering the drug. Withhold the drug if
Less than 60 in adults
Less than 90 in infants
More than 110 in adults
Retake pulse in one hour, if pulses remain abnormal, refer!

Implementation
Check the spelling of the drug- DIGOXIN is different from DIGITOXIN!
Check the dosage preparation and the level of digitalis in the blood. ( Therapeutic level is 0.5 to 2.0 nanograms/mL )
Administer intravenous drug VERY slow IV over 5 minutes to avoid arrhythmias. Do NOT administer intramuscularly because it can cause severe pain

Implementation
Administer the drug without food if possible to avoid delayed absorption . Weight patient daily to determine fluid retention
Maintain emergency equipment and drugs= Potassium salts, Lidocaine for arrhythmias, phenytoin for seizures, atropine for bradycardia.
Provide comfort measures- small, frequent meals, adequate lighting, comfortable position, rest periods and safety precautions

Implementation
Provide health teaching- drug name, action, dosage and side effects. Advise the patient to report any of the following: Visual changes, rapid weight gain, unusually low heart rate, persistent nausea, vomiting and anorexia
Monitor serum potassium level

Evaluation
Evaluate effectiveness of the drug:
Increased urine output
Normal heart rate in arrhythmia

The Antianginal drugs
In the treatment of angina, three agents are commonly employed-
Organic nitrates
Beta-blockers and
Calcium-channel blockers.
The benefits of the drugs lie in their different mode of action.

The nitrates can cause vasodilatation of the veins and to some extent, coronary artery

Beta-blockers will decrease the heart rate

Calcium-channel blockers will decrease force of contraction leading to a decreased myocardial workload and demand.
They can also produce vasodilation

The Organic nitrates
These agents are simple nitric and nitrous acid esters of alcohols. Being alcohol, they differ in their volatility. The following are the nitrates commonly used:
Nitroglycerin- A moderately volatile nitrate
Isosorbide Dinitrate (Isordil) or mononitrate
Amyl nitrate- an extremely volatile nitrate

Nitroglycerin
This agent is supplied in oral, spray, transdermal and ointment preparations.

Pharmacodynamics: the mechanism of action
Nitroglycerin relaxes the smooth muscles in the vascular system by its conversion to nitric oxide, a chemical mediator in the body that relaxes smooth muscles.

Administered nitrates
Increased nitrates in the blood
increased formation of nitric oxide
increased cGMP formation
increased dephosphorylation of myosin
Vascular smooth muscle relaxation
vasodilatation

Pharmacokinetics- absorption to excretion
It can be given orally, parenterally and topically.
The onset of action of nitroglycerin is more than 1 hour.
Because significant first-pass hepatic effect, Nitroglycerin is given SUBLINGUALY.

Pharmacodynamics: Side effects and adverse effects
HEADACHE is the most common effect of nitroglycerin .
CVS- postural Hypotension, facial flushing, tachycardia
TOLERANCE - the tolerance to the actions of nitrates develop rapidly. This can be managed by providing a day of abstinence.

The Nitrates
Implementation
Monitor vital signs, especially watchful for hypotensive episodes
Advise patient to remain supine or sit on a chair when taking the nitroglycerin for the first time. Emphasize that he should change his position slowly or rise from bed slowly to avoid orthostatic Hypotension
Offer sips of water before giving sublingual nitroglycerin because dryness may inhibit drug absorption

The Nitrates
Implementation
Apply nitroglycerin ointment to the designated mark on paper.
The nurse should remove any excess ointment on the skin from the previous dose.
She should NEVER USE her bare fingers because the drug can be absorbed, utilize gloves or tongue blades instead.

The Nitrates
Implementation
Apply nitroglycerin patch to an area with few hairs. Never touch the medication portion.
The patch and the ointment should NOT be applied near the area for defibrillation because explosion and skin burns may result

The Nitrates
IMPLEMENTATION
Emphasize that tolerance to the nitroglycerin can occur.
If the medication cannot relieve the pain, report to the hospital immediately.

The Nitrates
IMPLEMENTATION
Provide client health teaching- the sublingual nitroglycerin tablet is USED if chest pain occurs
The dose may be repeated if pain is unrelieved within 5 minutes.
Repeat the medication administration if the pain has not yet subsided .
DO NOT give more than 3 tablets! !! If chest pain persists for more than 15 minutes, hospital consult should be done immediately.

The Nitrates
IMPLEMENTATION
Instruct the client to avoid alcohol while taking nitroglycerin to avoid potentiating the hypotensive effect of the medication
If beta blockers and calcium-channel blockers are given, instruct the patients to consult the physician before discontinuing the medication

The Nitrates
IMPLEMENTATION
Other components of health teaching for home self-administration:
If taking Sublingual Nitroglycerin, the patient should be instructed to place the tablet under the tongue for quick absorption.
A burning sensation/biting/stinging sensation may indicate that the tablet is FRESH!
Store the tablet in a dark container , keep it away from heat and direct sunlight to avoid lessening the potency

The Nitrates
IMPLEMENTATION
HEADACHES are common in the initial period of nitroglycerin therapy. Advise patient to take PARACETAMOL for relief
The nitroglycerin patch is applied once a day, usually in the morning. The sites should be rotated, in the chest, arms and thighs avoiding hairy areas.

The Nitrates
IMPLEMENTATION
Position supine with elevated legs to manage Hypotension.
Nitroglycerin tablet can be taken prophylactically in situations where chest pain is anticipated- Sex, exercise, etc..
If patient is taking beta blockers, instruct how to obtain heart rate in a minute

Drugs for Shock
Dopamine
This is a sympathomimetic drug often used to treat Hypotension in shock states that are not caused by Hypovolemia.
This drug is an immediate precursor of nor-epinephrine, occurs naturally in the CNS basal ganglia where it functions as a neurotransmitter.

Drugs for Shock
Dopamine
Pharmacodynamics: It can activate the alpha and beta adrenergic receptor depending upon the concentration. It stimulates receptors to cause cardiac stimulation and renal vasodilation .
The dose range is 1-20 micrograms/kg/min

Drugs for Shock
Dopamine
Pharmacokinetics: Dopamine is administered IV, excreted in the urine.
At low dose ( 1-2 micrograms ), dopamine DILATES the renal and mesenteric blood vessels producing an increase output (dopaminergic effect)

Drugs for Shock
Dopamine
At moderate dose of 2-10 micrograms, dopamine enhance cardiac output by increasing heart rate ( beta 1-adrenergic effect) and elevates blood pressure through peripheral vasoconstriction (alpha adrenergic effect)

Drugs for Shock
Dopamine
At higher doses of more than 10 micrograms- vasoconstriction of all vessels will predominate that can lead to diminished tissue perfusion

Drugs for Shock
Dopamine
Dopamine is indicated to treat Hypotension, to increase heart rate and to increase urine output (given less than 5 mg/kg/min)
The nurse typically prepares the dopamine drip- dopamine (at a concentration of 400-800 mg) is mixed in 250 mL D5W and administered as drip via an infusion pump for precise dosage administration.
Sodium bicarbonate will inactivate the dopamine

Drugs for Shock
Dopamine
Pharmacodynamics: side effects- Tachycardia
hypertension
ectopic beats, angina, dysrhythmias, myocardial ischemia, nausea and vomiting.

Drugs for Shock
Dopamine: Nursing consideration
Check the IV site hourly for signs of drug infiltration of dopamine, which can cause tissue necrosis.
Phentolamine should be infiltrated in multiple areas to reduce tissue damage.
Drug is effective if Urine output is increased and BP is increased

Antihypertensive drugs
The Drugs employed to control hypertension can be classified as:
Diuretics
Beta-blockers
Alpha adrenergic blockers
Calcium channel blockers
Angiotensin-converting enzyme inhibitors
Angiotensin II receptor blockers
Peripheral vasodilators

Common Drugs in HPN
IN Evaluating the effectiveness of these drugs is simply to monitor the BP if it becomes NORMAL

Anti-hypertensive drugs Depression Stimulates CNS alpha 2 receptor Clonidine Central alpha agonist Urination Blocks alpha receptor in BV causing vasodilatation Prazozin Alpha blockers HEADACHE Dilates veins and arteries Nitroglycerin Vasodilator Headache, flushing, reflex tachycardia Blocks Ca entry into cell Nifedipine Ca channel blockers Headache, Cough, flushing Prevents A1 to AII conversion Captopril ACE Inhibitors Bradycardia, hypoglycemia Blocks B1 receptor in the heart Propranolol Beta-blocker Hypokalemia Decreases blood volume Furosemide Diuretics Side effects MOA Prototype Class

Anticoagulants SE: Bleeding SE: bleeding, decreased platelets Antidote: Vit. K Antidote: Protamine sulfate Small molecule CANNOT be given to pregnant Large molecule, can be given to pregnant Monitor for PT and INR Monitor for aPTT Acts within days Acts within minutes Action is to INHIBIT Vitamin-K dependent clotting factors (10,9,7,2) Action is to enhance natural anti-thrombin III in the blood Oral Parenteral (SQ and IV) WARFARIN HEPARIN

The antianemics: Iron preparations and Epoetin
Iron preparations
Iron is important for hemoglobin formation.
The iron preparations are:
Ferrous sulfate
Ferrous fumarate
Ferrous gluconate

Side-effects:
GIT- constipation (usually), diarrhea, vomiting, epigastric pain, gastric ulceration and darkening of stools.
Liquid preparation can stain the teeth, and injectable iron can cause tissue discoloration
Other- dizziness

Drug-Drug interaction
Tetracyclines combine with iron preparations and render the iron unabsorbable.
Antacids and cimetidine- decrease iron absorption and effects
Foods can impair iron absorption but they should be taken with iron to reduce GI discomfort.
Milk containing foods, coffee, tea and eggs are NOT given with iron because they delay iron absorption.

Implementation
Encourage the patient to eat iron-rich foods like liver, lean meat, egg yolk, dried beans, green leafy vegetables.
Administer iron preparations orally with foods to decrease GI discomfort.
If increased absorption is necessary, administer IN BETWEEN meals with full glass of water or juice.
It is best to offer citrus juices because the vitamin C content can increase iron absorption.
Instruct the patient to swallow the whole tablet and remain upright for 30 minutes to prevent esophageal corrosion from reflux.
DO NOT administer iron together with or within 1 hour of ingesting tetracyclines, antacids, milk and milk-containing products.
Advise clients to increase fluid intake and consume fiber rich foods if constipation becomes a problem.

Implementation
Emphasize that the therapeutic effect of iron therapy may not be apparent until several weeks.
If injecting a parenteral iron preparation, inject DEEP IM utilizing the Z-track method to avoid leakage into the subcutaneous tissues and skin .
Offer straw if giving liquid iron preparation to avoid staining the teeth.
To prevent undue alarm, instruct the patient that the stools may turn black or dark green. This is a harmless occurrence.

Evaluation
The nurse evaluates the effectiveness of the drug therapy by determining that the client is not fatigued, with absence of pallor, and with hemoglobin results within desired range .

Erythropoietin
The mechanism of action of epoetin alfa
(Epogen)
This drug acts like the natural glycoprotein erythropoietin to stimulate the production of RBC in the bone marrow.

Erythropoietin
Clinical indications
It is given SUBCUTANEOUSLY or INTRAVENOUSLY for the treatment of anemia associated with renal failure or for patients on dialysis .
It is also used in patients for blood transfusion to decrease the need for blood in surgical patients.

Erythropoietin
Pharmacodynamics: the adverse effects of epoetin alfa
CNS- headache, fatigue, asthenia, dizziness and seizures- these are due to the cellular response to the glycoprotein.
GIT- nausea, vomiting and diarrhea
CVS- hypertension, edema and chest pain due to increase RBC number

Erythropoietin
Implementation
Administer the drug SC or IV usually 3 times per week.
Monitor the IV access line if given IV. Do not mix with other solutions
Determine periodically the level of hematocrit and iron stores during therapy. If patient does not respond to the drug, reevaluate the cause of anemia.
Maintain seizure precaution on stand by as seizure can occur.
Provide comfort measures like small frequent feedings and pain medications for headache.
Provide thorough health teaching: need for lifetime injection

Erythropoietin
Evaluation
Monitor patient response to the drug= increased hemoglobin

Psychiatric Medications

Psychotrophic drugs
Drugs that can:
Stimulate the release of neurotransmitters
Block the receptor/activity of the neurotransmitter= like dopamine
Stimulate the receptors in the CNS
Prevents the breakdown of the neurotransmitters or the re-uptake mechanism

Anti-Psychotics/Neuroleptics
Drugs used to treat PSYCHOSES
MAIN ACTION: Blockage of the DOPAMINE receptor in the CNS

Anti-Psychotics/Neuroleptics quetiapine Risperidone Olanzapine Clozapine Atypical drugs Pimozide Diphenylbutlypiperidine Molindone Dibenzoxapine thirothixene Chlorprothixene Thioxanthines droperidol Haloperidol Butyrophenones Thioridazine, Fluphenazine, Perphenazine Chlorpromazine Phenothiazines Others Prototype Class

Anti-Psychotics/Neuroleptics Reduced flattening of affect 6 Relief of emotional turmoil 5 Reduced agitation resulting to calmness 4 Decreased ambivalence, reduced delusion 3 CNS sedation and emotional slowing 2 Reduced hallucination and illusions 1 Desired Effects

Anti-Psychotics/Neuroleptics Safety, no machine operation Sedation Monitor EEG Seizure Instruct to report sore throat and fever, monitor WBC Agranulocytosis Change position slowly, lie prone for 1 hour after drug intake, monitor BP Postural hypotension Sunglasses, sunscreen, avoid sun Photosensitivity Sugarless gum, bed rest Anticholinergic effects Nursing Interventions Common SE

Anti-Psychotics/Neuroleptics Notify physician, prepare to administer dantrolene Neuroleptic Malignant syndrome= elevated temp, treme muscle rigidity No treatment except discontinue drug Tardive Dyskinesia= irreversible drooling, tongue movement and shuffling gait Verbalize understanding of the condition, administer anti-EPS Akathisia= motor restlessness Remain with client, administer anti-EPS Dystonia- torticollis, contraction of face and tongue Avoid abrupt withdrawal, give anti-EPS drugs like Cogentin Parkinsonism-Tremor, rigidity, bradikinesia Nursing Intervention Extra-Pyramidal Syndrome

Review Outline
Adrenergic Agonists
Adrenergic Antagonists
Cholinergic Agonists
Cholinergic Antagonists

Comparison of the Sympathetic and Parasympathetic Nervous system Rest and Digest Fight or flight General response Acetylcholine-ESTERASE MAO, COMT Enzyme for NTA Acetylcholine Epi and NE Post-ganglionic NTA Short axon Long axon Post-ganglionic neuron Near target organ Next to spinal cord Ganglia location Acetylcholine Acetylcholine Pre-ganglionic NTA Long axon Short axon Pre-ganglionic neuron Cranio-Sacral spinal cord Thoraco-lumbar spinal cord CNS origin Parasympathetic Sympathetic Characteristics

The autonomic drugs
Pharmacologic use depends on their EFFECTS on the body
They can STIMULATE= agonists OR mimetics
They can DECREASE THE RESPONSE= antagonists OR blockers

The autonomic drugs
They can STIMULATE= agonists OR mimetics
DIRECT STIMULATION by binding with receptors
INDIRECT STIMULATION by blocking the enzymes that degrade the neurotransmitters or increasing the release of neurotransmitters

The autonomic drugs
They can DECREASE THE RESPONSE= antagonists OR blockers
DIRECT blockage by removing the neurotransmitter or competing with the neurotransmitter
Binding with the receptor and NO RESPONSE will happen

The autonomic drugs
They can be
NON-SELECTIVE when they stimulate or block many receptors
SELECTIVE when they stimulate or block specific receptors
SPECIFIC when only ONE type of receptor is stimulated or blocked

The autonomic drugs: Pharmacologic use depends on their EFFECTS on the body Used for HYPERTENSION and Tachycardia Decreases BP and heart rate Used for SHOCK where there is LOW BP Increases BP Therapeutic use Effect on the body

The Adrenergic AGONISTS
Also called SYMPATHOMIMETIC agents
These drugs MIMIC the effects of the sympathetic nervous system

They usually stimulate DIRECTLY the receptors of the adrenergic system

Alpha and Beta agonists (non-selective)
Prototype: Epinephrine
Alpha Agonists (Selective)
Prototype: Phenylephrine
Beta Agonists (Selective)
Prototype: Isoproterenol

Alpha and Beta agonists (non-selective)
Pharmacodynamics:
These agents stimulate ALL types of adrenergic receptors in the body by direct interaction or by releasing neurotransmitters from the nerve cells

Alpha and Beta agonists
Prototype: Epinephrine
1. Ephedrine
2. Epinephrine
3. Metaraminol
4. Norepinephrine
5. Dobutamine (sometimes a B1 specific)
6. Dopamine

Alpha and Beta agonists: Clinical Use
1. Dopamine- used in shock
2. Epinephrine- drug of choice of anaphylaxis, Status asthmaticus
3. Norepinephrine- used in shock
4. Dobutamine- used in CHF
5. Ephedrine- used in shock, asthma and rhinitis

Alpha and Beta agonists: Desirable effects
Increased myocardial contractility
Bronchial DILATATION
Vaso constriction
Increased blood pressure
Decreased intraocular pressure
Pupillary dilatation

Alpha and Beta agonists: Contraindications
Pheochromocytoma
Tachyarrhythmias
With halogenated anesthesia- increased sensitivity to adrenergic drugs

Alpha and Beta agonists: Adverse effects
Sympathetic stimulation effects
CVS- hypertension, tachycardia, palpitations
Respi- tachypnea
GI- nausea, vomiting
Others- sweating, headache, piloerection

Alpha and Beta agonists: Nursing considerations
Monitor patient response to the drug
Emphasize to avoid the use with MAOIs and TCA
Maintain phentolamine (alpha blocker) to manage extravasation of IV drug
Usually given IV

Alpha and Beta agonists: Nursing considerations
Determine effectiveness of the drug:
Increased BP in shock
Relief of anaphylaxis and asthma attack
Relief of nasal congestion

Alpha Agonists (selective)
Prototype: phenylephrine
clonidine (alpha-2 specific)

Alpha Agonists Pharmacodynamics:
These agents bind primarily to the alpha receptors in the body
Clonidine
Stimulating the ALPHA-2 receptor causes decreased sympathetic outflow from the CNS/ decreased release of NE

Alpha Agonists: Clinical use
Phenylephrine- vasoconstricting drug, used topically to decrease the symptoms of rhinitis
Clonidine- for hypertension

Alpha Agonists: Contraindication
Allergy to drug
Caution in the following conditions:
Hyperthyroidism-aggravation of symptoms
Diabetes- increased glucose levels
Tachyarrhythmias- possible additive effect

Alpha Agonists: Adverse effects
CNS- anxiety, depression , fatigue
CVS- palpitations
GI- nausea, vomiting and anorexia
GU- oliguria, dysuria

Alpha Agonists: Nursing considerations
1. DO NOT discontinue drug abruptly to prevent rebound effect
2. Maintain phentolamine if giving IV drug
3. Provide comfort measures- rest, quiet environment, analgesics

Alpha Agonists: Nursing considerations
Evaluate effectiveness:
Decreased BP
Decreased Nasal congestion

Beta Agonists (Selective): ANTI-ASTHMA DRUGS
Prototype: isoproterenol (B1 and B2)
salbutamol (Ventolin)= B2 specific
Ritodrine (B2 specific)
“ terol”- albuterol, salmeterol, bitolterol
Terbutaline (B2)

Beta Agonists Pharmacodynamics
These agents bind to the BETA receptors causing the sympathetic manifestations and effects

Beta Agonists Clinical use
Asthma- due to the bronchodilation !
Preterm labor- ritodrine is given to relax the uterine muscles
Shock= To increase BP

Beta Agonists Adverse effects
CNS- restlessness, headache, anxiety , tremors
CVS- tachycardia , angina, palpitations
GI- nausea, vomiting and anorexia
Others- pupilary dilation, rash, sweating, pulmonary edema

Beta Agonists Nursing considerations
Monitor VS when giving the drug
Remind mothers to lie on the left side during ritodrine administration
Maintain a beta blocker on stand by
Provide comfort- quiet environment, rest, analgesics.
Prevent over-hydration to avoid pulmonary edema

Beta Agonists Nursing considerations
These are given usually inhalational for asthma attack
Instruct on how to use inhalers and nebulizers
Normal RR
Clear breath sounds

The Adrenergic ANTAGONISTS
These are called adrenergic blockers
They can be Alpha Blockers (selective)
Beta Blockers (selective)
Both Alpha & Beta Blockers
(non-selective)

The alpha blockers (selective)
Prototype: Phentolamine
Phenoxybenzamine
“ zosin”- prazosin, doxazosin, terazosin- these are alpha 1 blockers

The alpha blockers: Pharmacodynamics
These agents have affinity for the ALPHA receptors
Blocking the alpha receptors will cause:
Vasodilation
Sphincter relaxation in the bladder

The alpha blockers: Clinical use
Phenoxybenzamine- used in pheochromocytoma
Phentolamine- also used in pheochomocytoma
“ zosin” drugs- are used to decrease blood pressure and to relax the urinary sphincter in BPH!

The alpha blockers: Contraindications
Myocardial infarction
Allergy

The alpha blockers: Adverse Effects
CVS- hypotension, reflex tachycardia, flushing
CNS- dizziness, weakness, fatigue, drowsiness
Others- nasal congestion, reddened eyes, priapism

The alpha blockers: nursing consideration
Monitor heart rate and BP
Caution to change position slowly
Advise to avoid hazardous activities
Provide supportive measures like quiet environment, rest and analgesics
Monitor response to the drug- improvement of blood pressure readings and urination

The Beta blockers
These are agents used to treat cardiovascular problems- Hypertension, CHF, angina
Blocking beta receptor will cause
decreased heart rate
decreased BP

The Beta blocker or The “olol”s
They can be beta 1 blockers, beta 2 blockers or Both
Prototype of non-selective: propranOLOL (beta 1 and 2)
carteOLOL
nadOLOL
penbutOLOL
sotaLOL

The Beta blocker or The “olol”s
They can be beta 1 blockers, beta 2 blockers or Both
Prototype of B1 selective : atenOLOL
acebutOLOL
betaxOLOL
esmOLOL
metoprOLOL

The Beta blockers: pharmacodynamics
These agents block the beta receptors of the sympathetic system. The selective B1 antagonists block the B1 receptors, especially in the heart and the kidney

The Beta blockers: Clinical use
Hypertension
Angina and MI
Cardiac arrhythmias
Migraine headache
HYPERTHYROIDISM

The Beta blockers: Clinical use
to decrease the tachycardia HYPERTHYROIDISM to cause vasoconstriction in the cranial vessels Migraine headache to terminate arrhythmias Cardiac tachyarrhythmias to decrease cardiac workload Angina and MI to decrease BP Hypertension

The Beta blockers: contraindications
Allergy
Heart blocks
Bradycardia
COPD
Precaution in DM

The Beta blockers: Adverse effects
CVS- bradycardia, hypotension, heart block
CNS- fatigue, dizziness, depression
Respi- bronchospasm , pulmonary edema
GI- nausea, vomiting, diarrhea, hypoglycemia
GU- decreased libido , impotence, dysuria

The Beta blockers: nursing considerations
Emphasize NOT to stop abruptly the drug intake
Give with FOODS to improve absorption
Provide comfort measures
Adequate rest periods
Avoidance of hazardous activities
Change position slowly

The Beta blockers: nursing considerations
Decreased BP in hypertension
Decreased HR in hyperthyroidism
Decreased PAIN angina

Drugs for the parasympathetic system (cholinergic drugs)

The Cholinergic Agonists
These are also called parasympathomimetic agents
Their action mimics the parasympathetic nervous system

These agents INCREASE the activity of acetylcholine in the acetylcholine receptors
DIRECTLY by occupying the receptor
INDIRECTLY by blocking the enzyme that degrades the acetylcholine, preventing it from breakdown - the enzyme: acetylcholin ESTERASE

Direct acting cholinergic agonists
Prototype: BetaneCHOL
CarbaCHOL
Pilocarpine
Indirect acting cholinergics
Prototype: Pyridostigmine
Neostigmine
Endrophonium (Tensilon)

Pharmacodynamics
They are similar to acetylcholine and directly act on the acetylcholine receptors

Parasympathetic stimulation will cause:
DUMBELS
urination
miosis (pupil constriction)

Direct acting cholinergic agonists: Clinical use
Post operative and post partum urinary retention and to treat neurogenic bladder
Relief of increased intraocular pressure of glaucoma by inducing miosis

Direct acting cholinergic agonists: Clinical use
The drugs INCREASE the bladder tone, RELAX the GI and urinary sphincters
The topical agent (pilocarpine) topically causes pupilary constriction to reduce IOP

Direct acting cholinergic agonists: Contraindications
Bradycardia
Hypotension
Asthma

Direct acting cholinergic agonists: Adverse effects (DUMBELS)
CVS- bradycardia , heart block, hypotension
GIT- nausea, vomiting, diarrhea, increased salivation, lacrimation
GUT- sense of urgency , sphincter relaxation
Others- increased sweating , headache, miosis

Direct acting cholinergic agonists: nursing considerations
Assure proper administration of ophthalmic preparations
Administer on EMPTY stomach
Provide safety precautions- because of poor visual acuity
Promote cool environment, maintain access to the bathroom (urination)

The Cholinergic Agonists: evaluate effectiveness Urination/ relief of bladder distention Betanechol/Carbachol Decreased IOP in glaucoma Pilocarpine effectiveness Drug

Indirect acting cholinergic agonists
Pharmacodynamics
These agents DO NOT react directly with the receptors but REACT chemically with the enzyme= acetylcholin esterase

Pharmacodynamics
The acetylcholine breakdown is prevented so that the effect of acetylcholine is prolonged!= increased muscle contraction
They are used IN myasthenia gravis

Clinical use
Myasthenia gravis
Physostigmine, pyridostigmine , Neostigmine, and endrophonium
2. Alzheimer's disease
Tacrine and Donepezil

Adverse effects
GI- nausea, vomiting, cramps, diarrhea, increased salivation , involuntary defection
CVS- bradycardia , heart block, hypotension
GU- urinary urgency
Others- blurred vision , miosis, headache, dizziness

Nursing considerations
Administer IV drug slowly
Administer with foods BUT better BEFORE meals
Maintain atropine sulfate as antidote
Discontinue the drug if excessive salivation, diarrhea, vomiting become problematic

Evaluate effectiveness
Decreased muscle weakness
Decreased dysphagia, ptosis
Increased muscular activity

The ANTI-cholinergics
These are drugs that BLOCK the effect of acetylcholine
They are also called parasympatholytic agents
In effect, the sympathetic system becomes unopposed!!!

Anticholinergics:
Prototype: Atropine
dicyclomine
glycopyrrolate
propantheline
scopolamine

Anticholinergics: pharmacodynamics
These agents work by BLOCKING or COMPETING with acetylcholine for the acetylcholine receptors
BEST taken BEFORE MEALS

Atropine
Depresses salivation
Decreases bronchial secretions
Mydriasis
Cyclopedia
Inhibits vagal response in the heart
Reverses cholinergic toxicity

Atropine Used in partly to control diarrhea (in Lomotil ) Constipation Used in Cholinergic and Organophosphate poisoning Reverses cholinergic toxicity Used in BRADYCARDIA and heart block Inhibits vagal response in the heart Used in cataract surgery Cyclopledia Used in cataract surgery Mydriasis Used as pre-op med Decreases bronchial secretions Used as pre-op med Depresses salivation Clinical use effects

Scopolamine
Decreases nausea and vomiting associated with motion sickness

Anticholinergic
Contraindications of anticholinergic
Known allergy
Glaucoma
Bladder obstruction (like PBH)

Anticholinergic
Adverse effects: anticholinergic effects
CNS- blurred vision, pupil DILATION, photophobia, cycloplegia and increased Intraocular pressure
GI- dry mouth , constipation, bloatedness
CVS- tachycardia, palpitations
GU- urinary retention
Others- decreased sweating, flushing

Anticholinergic
Provide comfort measures
Frequent mouth care
Provide increased fluids
Protect eyes form lights
Advise to avoid hazardous activities
Provide high-fiber diet and laxative
Avoid extremes of temperature
Instruct to void before administering the drug

Anticholinergic
2. Monitor for toxicity:
3. Ensure adequate hydration to prevent hyperpyrexia
Evaluate effectiveness of drug:
Increased HR in heart block
Decreased secretions in pre-op patients
Relief of motion sickness (scopolamine)

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NurseReview.Org Pharmacology Bullet Review

by Nurse ReviewDotOrg on Nov 10, 2007

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