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

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