Pharmacology, Rational Drug Use, and Prescription Standards
What candidates must know
Candidates must know pharmacokinetics (absorption, distribution, metabolism, excretion) and pharmacodynamics (receptors, agonists, antagonists, dose-response). Learn major drug classes: antibiotics, antihypertensives, antidiabetics, anticoagulants, analgesics, and emergency drugs. Rational drug use means choosing the right drug, dose, route, and duration based on evidence, avoiding unnecessary antibiotics, and considering interactions, renal and hepatic adjustment, pregnancy safety, and pediatric dosing. Prescription standards cover legal requirements: prescriber details, patient identification, drug name, dose, formulation, directions, quantity, and signature, plus rules for controlled substances and prescription validity.
Traps in questions
Common traps include interaction questions (for example, warfarin with enzyme inhibitors or inducers), prescribing to pregnant patients with contraindicated drugs, and failing to adjust doses in renal impairment. Another trap is the assumption that a broad-spectrum antibiotic is always better; rational use favors the narrowest effective agent. Questions may test the difference between adverse drug reaction and medication error. Watch for duplicate therapy and for over-the-counter interactions.
Worked example: rule of thumb
A patient on warfarin develops an infection and is prescribed a macrolide: anticipate a rise in INR and plan monitoring. Rule of thumb: any new drug in a patient on a narrow-therapeutic-index medication demands an interaction check. For prescriptions, verify all legally required elements; an incomplete prescription is not merely a clerical issue but a legal and safety failure.