Pharmacology and Medication Administration
What this domain tests
Pharmacology and Medication Administration tests the rights of administration, pharmacokinetics, high-alert medications, calculations, and recognition of adverse effects and antidotes.
Core rules
- Rights: right patient, drug, dose, route, time, documentation, reason, and response; many services add the right to refuse.
- High-alert medications include insulin, heparin, opioids, chemotherapy, and concentrated electrolytes. Independent double-checks and standardized concentrations reduce harm.
- Pharmacokinetics: absorption, distribution, metabolism (mostly hepatic), excretion (mostly renal). Adjust doses in renal and hepatic impairment.
- Never give IV push potassium, never give oral medications to a patient who cannot swallow safely, and never crush extended-release tablets without verification.
- Antidotes: naloxone for opioids, flumazenil for benzodiazepines, protamine for heparin, vitamin K for warfarin, acetylcysteine for acetaminophen, calcium gluconate for magnesium toxicity.
- Calculate by dimensional analysis and check the result against the safe dose range.
Worked example
Order: dopamine 5 mcg/kg/min for an 80 kg adult. Pharmacy supplies 400 mg in 250 mL. What rate in mL/hr? Reasoning: dose = 5 x 80 = 400 mcg/min = 24,000 mcg/hr. Concentration = 400,000 mcg in 250 mL = 1,600 mcg/mL. Rate = 24,000 / 1,600 = 15 mL/hr. Estimate to check: each mL delivers four minutes of the dose at 400 mcg/min, so 15 mL/hr is consistent.
Traps
- Rounding mid-calculation and reporting an unsafe volume.
- Confusing milligrams and micrograms, a common source of tenfold errors.
- Giving IV push medications faster than the recommended rate.
- Monitoring for therapeutic effect but not toxicity, such as digoxin bradycardia or aminoglycoside nephrotoxicity.