Hypothyroidism is caused by an abnormality in the thyroid gland that prevents the release or production of thyroid hormones. Symptoms include decreased metabolism, goiter, hair loss, and constipation. Levothyroxine is used to treat hypothyroidism but can cause cardiac issues or palpitations if not taken properly. A thyroidectomy can potentially cause complications from an overdose of thyroid replacement drugs. Medications can be administered by different routes that affect their absorption rate and extent. Oral medications pass through the stomach and liver first, while sublingual and parenteral routes provide faster absorption. The major organ systems involved in drug excretion are the liver, kidneys, intestines

1. Study Guide – Pharmacology Test #1
Thyroid Gland and hypothyroidism: Abnormality in the thyroid gland. Unable to release thyroid hormones from their storage
sites, coupling iodine with tyrosine, trapping iodine, or converting iodide to iodine or any combination. Pituitary gland dsfx and
does not secrete TSH to trigger release of T3 and T4. Or level of thyrotropin releasing hormone TRP secreted from hypothalamus
is reduced, which results in decreased TSH levels
Symptoms: decreased BMR, goiter, thickened skin, hair loss, lethargy, constipation and anorexia.
Synthroid (levothyroxine)
SE/AE: What does it cause? Cardiac dysrhythmia , palpitations, weight loss
Primary teaching points: Do not d/c meds, take at the same time every day, do not switch brands, report chest
pain/palpitations, effects may take several months to occur. Always consult your physician before taking OTC meds with
levothyroxine.
Thyroidectomy, potential complications/symptoms: OD of thyroid replacement drugs.
Agonist vs. Antagonist
Agonist: binds/stimulates the activity of one or more biochemical receptors in the body…elicits a response
Antagonist: binds to and inhibits the activity of one or more biochemical receptors (inhibitors).
Define forms of meds:
Compressed: scored/shiny coat; keeps dust from forming and keeps from sticking to throat
Sustained release (SR): releases drug in controlled/predictable manner; enteric coating to create barrier against stomach
acids
Osmotic pump: tabs with semiperm. Membrane which allows H20 to enter and drug leave slowly through small hole
made by laser when forming the tablet
Repeat action: second dose within inner shell
Why meds are given one route vs. another
Its route of administration effects the rate and extent of absorption of that drug.
Enteral: absorbed into systemic circulation through oral/gastric mucosa, small int. or rectum. Absorbed from GI into
portal circulation (liver). It may be extensively metabolized by liver before reaching systemic circ
Oral: stomach can alter meds, pH, food, etc. Exercise/sepsis cause blood flow to GI tract to be reduced
Sublingual: rapid absorption
Parenteral: fastest route followed by enteral and topical routes. Refers to any route of admin other than GI tract.
SubQ and IM: long acting dosages that take several hours to absorb.
Topical: long lasting, local effects with some drugs, but slow in onset and prolonged in offset.
Transdermal: bypasses liver and first pass effect, and suitable for pt. who cannot tolerate PO
Inhalation: Pulmonary; absorption occurs at the pulmonary alveolus in contact w/ capillaries.
Med errors as a nurse – how to reduce risk
What is a medication error? “ Any preventable event that may cause or lead to inappropriate med use or pt. harm while the
med. Is in control of the healthcare providers, pt. or consumer…”
Assessing all parameters w/pt. (vitals, labs & document).
Assessing pt. for effects of drugs and consulting reference materials or colleages.
Completing ME reporting forms after contacting MD or charge nurse.
Monitor pt. progress/condition.
Think/act critically to prevent further errors.
Conducting detailed RCE (root cause errors).
Analyze methods to reduce complexity of drug administration.
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2. Transcribing MED order, you can’t read it. What action do you take?
Repeat order to confirm with prescriber – never assume!
Definitions:
Adverse drug event: an injury caused by a medicine or failure to admin. Intended med (may/not be preventable and
may/not cause harm)
Adverse drug reaction: an unexpected, unintended, undesired or excessive response to a med. (may/not be preventable; i.e.
error)
Allergic reaction: immunologic hypersensitivity reaction resulting from unusual sensitivity of pt. to a drug.
Idiosyncratic reaction: abnormal/unexpected susceptibility to a medication (other than allergy) peculiar to an individual
patient.
Pharmacuetics: Science of drug dosage form design.
Pharmacodynamics: Study of biochemical/physiologic interaction of drugs.
Pharmacogenetics: study of genetic factors & their influence on drug response (absence, overabundance, insufficiency of
drug metabolism enzymes).
Pharmacognosy: study of drugs obtained from natural/plant resources.
Pharmacokinetics: study of drug distribution rates between various body compartments, after drug has entered body
including (Absorption, Distribution, Metabolism, and Excretion).
Empiric theory: admin of antibiotics based on most likely pathogens causing infx.
Prophylactic antiB therapy: taken before anticipated exposure
Host factor: unique to the body of particular pt. I.e: pregnancy, genetics, site of infx, host defenses, determines success or
failure of antiB therapy.
B receptors: heart rate increases and bronchial relaxation
B1: cardiac, B2: smooth muscle, glands and lungs.
Excretion: properties of elimination, which organ systems are involved and how do they excrete?
Drugs metabolized by liver are more polar and H20 soluable…by glucuronidasees and hydroxylation/acetylation) Kidneys
themselves can form glucorunides and sulfates from various drugs and their metabolites. Filtered via glomerlar filtration,
reabsorptiona nd tubular secretion – go through glom. Filtration between the blood vessels and afferent arterioles &
glomeruli.
Intestines: fat soluble drugs; once in bile, resorbed into bloodstream, returned to liver & again secreted into the bile…this
is called enterohepatic circulation
Lungs, sweat, salivary and mammary glands excrete drugs.
What is distinctive about each of these medications?
Erythromycin: (Macrolide)
Inhibits protein synth. @ 50S ribosome
Contraindicted: hepatic/renal dysfx
Upset GI
Azythromycin (Zithromax) (Macrolide)
Inhibits protein synth @ 50S ribosome
Trimethoprimsulfamethoxazole (Septra) (Sulfanamide)
Inhibits metabolism of folic acid
Prevents prophylaxis of HIV
Bronchitis
Gonorrhea
Rapid PO
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3. Tetracycline
Inhibits bacteria @ 30S
Discolors teeth in children
Photosensitivity and avoid DAIRY
Contraindicted in pregnancy, and children < 8
Allupurinol
Inhibits (xanthine oxidase) production of uric acid – lowering serum uric acid
Contraindictions: oral hypoglycemic/warfarin increase efx of drugs
*watch kidney fx (toxicity)
Cefazolin (Ancef) Cehpalosporin
IM or IV
Contraindicted: penicillin allergies
Gentamycin (Aminoglycoside) gram (-) and (+)
*serious toxicities NEPHRO/OTO
Interactions: diuretics, skeletal musc. relaxants, anticoags.
Tobramycin (Aminoglycoside) gram (-) and (+)
*serious toxicities NEPHRO/OTO
psueudomonas
Interactions: diuretics, skeletal musc. relaxants, anticoags.
Ciprofloxin (Cipro) Fluroquinolone gram (+) and (-)
Inhibits DNA gyrase
s. aureus
Contraindicted: Pregnancy/child..alters efx of warfarin, inc. BUN and serum creatinine labs
Vancomycin (Fluroquinolone) gram (+) and (-)
Inhibits DNA gyrase
MRSA
Contraindicted: Pregnancy/child..alters efx of warfarin, inc. BUN and serum creatinine labs
Amoxicillin
Ped. Drops/tabs
Infx: ears, nose throat, GU, skin
Contraindictions: PKL, watch renal insuff. Decreases contraceptives (warfarin)
Insulin lispro (Humalog)
Rapid acting: onset 15m, peak 60-90m, dur 3-4h
Regular insulin (Humulin R)
Short acting: onset 30m, peak 2-3h, dur. 4-6 h
NPH (Lente)
Intermediate acting: onset 2 h, peak 6-8h, dur 12-16h
Humulin U (Ultralente)
Long-acting: onset 2 h., peak 16-20h, dur 24+h
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4. Sulfonylureas: increase secretion of insulin (stimulate B cells of pancreas). Pt. must have firing pancreas & no sulfa
allergies
A/E: hypoglycemia
Salicylates (Acetic acids) fever, pain, arthritis, thrombolytic; NSAIDs blocks the LT (except ASA) and PG pathway specifically
by blocking COX or lipooxygenase
Proprionic Acids – tx of rheumatoid arthritis, etc. not for nursing women, preg. Cat D
Alpha – glucagons
Beta – insulin
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