Pharmacology and Medication Administration
Pharmacology questions test the rights of administration, accurate calculation, and recognition of high-alert drugs and their adverse effects. Cambodia's national guidelines rely on a short list of essential medicines, so know those well.
Rights and checks
Right patient, drug, dose, route, time, documentation and reason, plus the right to refuse. Check allergies, weight, renal and hepatic function, and interactions. High-alert medicines - insulin, oxytocin, magnesium sulfate, potassium chloride, heparin, opioids and chemotherapy - require an independent double-check and clear labelling.
Calculation method
Dose required ÷ stock strength × stock volume. Convert to the same unit first, and estimate the answer before calculating so a tenfold error is obvious.
Worked example
A 12 kg child needs paracetamol 15 mg/kg per dose. Required dose = 15 × 12 = 180 mg. Stock is syrup 120 mg/5 mL, so volume = 180 ÷ 120 × 5 = 7.5 mL. Reasonableness check: 180 mg is one and a half times the 120 mg contained in 5 mL, so 7.5 mL fits.
Traps
Confusing milligrams with millilitres; forgetting that a paediatric dose is per kilogram per dose, not per day; giving potassium chloride as a bolus (it must be diluted and infused); stopping tuberculosis treatment when the patient feels better; ignoring the maximum dose in an obese adult.