Pharmacology and Medication Safety
Medication questions test the rights of administration, pharmacokinetics, and recognition of adverse effects. The classic rights: right patient (two identifiers), right drug, right dose, right route, right time, right documentation - plus right reason and right to refuse.
High-alert medications: insulin, anticoagulants, opioids, chemotherapy and concentrated electrolytes carry the highest harm risk. They require independent double-checks, standard concentrations and clear labelling. Never administer a drug prepared by someone else without verification.
Key concepts:
- Pharmacokinetics: absorption, distribution, metabolism (liver), excretion (kidney). Renal or hepatic impairment alters dosing.
- Therapeutic index: narrow-index drugs (digoxin, warfarin, lithium, gentamicin) require monitoring levels.
- Adverse effects: know the classic ones - aminoglycosides (ototoxicity, nephrotoxicity), NSAIDs (GI bleeding, renal effects), ACE inhibitors (dry cough, hyperkalaemia), opioids (respiratory depression - naloxone antidote), benzodiazepines (sedation - flumazenil), paracetamol overdose (liver damage - acetylcysteine).
- Interactions: grapefruit with statins, warfarin with many drugs and vitamin K-rich foods.
Error prevention: question illegible or unusual orders, use the rights, report errors honestly through incident systems, and document. Look-alike/sound-alike names are a known hazard.
Traps
- Administering a dose outside the safe range without clarification.
- Choosing to "hold" a drug without checking parameters (e.g., digoxin and pulse, anticoagulants and INR).
- Forgetting to check allergies before administration.
Rule of thumb
If a dose or order seems wrong or unclear, stop and clarify with the prescriber - the safe answer is almost never "give it anyway".