Pharmacology and Nutrition
Pharmacology and Nutrition
Pharmacology tests drug classes, calculations, antidotes and interactions; Nutrition tests nutrients, deficiency diseases and therapeutic diets. Calculation questions are usually simple but must be shown stepwise.
Core rules
- Antidotes: paracetamol → N-acetylcysteine; opioid → naloxone; warfarin → vitamin K; heparin → protamine sulphate; organophosphate → atropine plus pralidoxime; digoxin → digoxin immune Fab.
- Dose formula: amount to give = (desired dose ÷ stock dose) × stock volume.
- Vitamins: A deficiency causes night blindness; B1 beriberi; B3 pellagra; C scurvy; D rickets; K bleeding tendency.
- Iron absorption improves with vitamin C and is reduced by tea and calcium.
- Therapeutic diets: diabetic low refined carbohydrate, renal low protein and low potassium, liver low fat.
Worked example
Order 250 mg; stock 500 mg in 5 mL. Amount = (250 ÷ 500) × 5 = 0.5 × 5 = 2.5 mL. Check the units match before calculating.
Traps
- Digoxin toxicity: bradycardia, nausea and yellow vision; check the apical pulse before giving.
- Warfarin INR target is usually 2–3.
- Tetracycline should not be taken with milk or antacids because absorption falls.