PSA Medication Safety 3 — Questions and Answers
Question 1: Before initiating amiodarone therapy, which baseline investigations are most essential?
- Full blood count and ESR only
- Thyroid function tests, liver function tests, and chest X-ray (Correct answer)
- Random glucose and HbA1c
- Renal function and urine dipstick only
Correct answer: Thyroid function tests, liver function tests, and chest X-ray
Amiodarone is iodine-rich and can cause thyroid dysfunction, hepatotoxicity, and pulmonary toxicity, so TFTs, LFTs, and CXR are mandatory at baseline.
Question 2: A patient on lithium presents with coarse tremor, vomiting, diarrhea, and confusion. What is the most likely cause?
- Acute psychosis exacerbation requiring dose increase
- Lithium toxicity (Correct answer)
- Serotonin syndrome from an unidentified drug
- Severe dehydration alone without drug accumulation
Correct answer: Lithium toxicity
Coarse tremor, GI upset, and neurotoxicity are hallmarks of lithium toxicity requiring urgent assessment and management.
Question 3: A patient on long-term methotrexate for rheumatoid arthritis requires regular monitoring. Which combination of tests is most important?
- Weekly ECG and blood pressure monitoring
- Full blood count and liver function tests at regular intervals (Correct answer)
- Monthly INR and serum albumin
- Daily blood glucose and HbA1c
Correct answer: Full blood count and liver function tests at regular intervals
Methotrexate causes bone marrow suppression and hepatotoxicity, making regular FBC and LFTs essential for safe long-term use.
Question 4: A patient is being initiated on clozapine for treatment-resistant schizophrenia. Which monitoring is mandatory due to a life-threatening adverse effect?
- Monthly thyroid function tests for hypothyroidism
- Regular white blood cell count to detect agranulocytosis (Correct answer)
- Weekly renal function tests for nephrotoxicity
- Daily ECG monitoring for the first month
Correct answer: Regular white blood cell count to detect agranulocytosis
Clozapine carries a mandatory WBC and neutrophil monitoring program because it can cause potentially fatal agranulocytosis in 1-2% of patients.
Question 5: A patient on ramipril for hypertension develops a persistent dry cough. What is the most appropriate next step?
- Add codeine linctus as a cough suppressant and continue ramipril
- Switch to an angiotensin receptor blocker such as losartan (Correct answer)
- Halve the dose of ramipril and reassess in four weeks
- Add a daily antihistamine and review in six weeks
Correct answer: Switch to an angiotensin receptor blocker such as losartan
ACE inhibitor-induced cough is a class effect caused by bradykinin accumulation; switching to an ARB eliminates the cough while maintaining antihypertensive efficacy.
Question 6: Stevens-Johnson syndrome is a severe mucocutaneous adverse drug reaction most classically associated with which medication?
- Amoxicillin
- Standard-dose ibuprofen
- Carbamazepine (Correct answer)
- Metformin
Correct answer: Carbamazepine
Carbamazepine and other aromatic anticonvulsants, along with allopurinol and sulfonamides, are strongly associated with Stevens-Johnson syndrome and toxic epidermal necrolysis.
Question 7: A patient receiving gentamicin for sepsis should be monitored primarily for which two toxicities?
- Hepatotoxicity and pancreatitis
- Nephrotoxicity and ototoxicity via serum creatinine and drug levels (Correct answer)
- Bone marrow suppression and alopecia
- Pulmonary toxicity and photosensitivity
Correct answer: Nephrotoxicity and ototoxicity via serum creatinine and drug levels
Aminoglycosides like gentamicin are dose-dependently nephrotoxic and ototoxic; serum creatinine and trough/peak drug levels must be monitored regularly.
PSA Medication Safety 3
Before initiating amiodarone therapy, which baseline investigations are most essential?