Patient Counselling & Drug Interactions Flashcards
6 cards from real PSI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Patient Counselling & Drug Interactions flashcards as text
A patient is prescribed ACE inhibitor ramipril and potassium-sparing diuretic spironolactone together. The risk is:
Answer: Hyperkalaemia — both drugs increase serum potassium
Both ACE inhibitors (reduce aldosterone-driven potassium excretion) and spironolactone (block aldosterone receptors) raise serum potassium. Combination increases hyperkalaemia risk — monitor electrolytes closely.
When counselling a patient on oral combined contraceptive pills (COC), which advice is most important regarding missed pills?
Answer: If 2 or more pills are missed, use additional contraception for 7 days and consider emergency contraception depending on timing
Current FSRH guidance: if 2+ pills missed, contraceptive efficacy is reduced. Additional barrier contraception for 7 days and consideration of emergency contraception (if unprotected sex during pill-free week or start of pack) is advised.
A patient on MAO inhibitor phenelzine is brought into the pharmacy having eaten aged cheese. They complain of severe headache. This suggests:
Answer: Hypertensive crisis due to tyramine interaction (cheese reaction)
MAO inhibitors block breakdown of dietary tyramine (found in aged cheese, fermented foods, red wine). Tyramine accumulation causes massive noradrenaline release, causing hypertensive crisis — a potentially fatal emergency.
Which interaction should a pharmacist counsel a patient about when dispensing sildenafil for erectile dysfunction?
Answer: Absolute contraindication with organic nitrates (GTN, isosorbide) — risk of fatal hypotension
Both sildenafil (PDE-5 inhibition) and nitrates (cGMP elevation via guanylate cyclase) cause vasodilation. Combined, they produce profound, potentially fatal hypotension. Nitrates are an absolute contraindication.
A patient on warfarin asks about taking cranberry juice. The pharmacist should advise:
Answer: Avoid large amounts — cranberry juice may inhibit CYP2C9, raising warfarin levels and INR
Cranberry juice, especially in large quantities, may inhibit CYP2C9 (warfarin's main metabolic pathway), increasing INR and bleeding risk. Case reports and pharmacovigilance data support caution with regular large intakes.
Which counselling point must be given to a patient starting metronidazole?
Answer: Avoid alcohol completely during treatment and for 48 hours after — causes disulfiram-like reaction
Metronidazole inhibits acetaldehyde dehydrogenase. Alcohol consumption causes acetaldehyde accumulation producing flushing, nausea, vomiting, palpitations and hypotension — the disulfiram-like reaction.