DHA Pharmacy & Medication Management 5 — Questions and Answers
Question 1: A patient taking sildenafil for erectile dysfunction is prescribed isosorbide mononitrate for angina. What is the pharmacist's correct action?
- Dispense both with a food interaction warning
- Contact the prescriber — concurrent use is absolutely contraindicated due to severe hypotension risk (Correct answer)
- Counsel the patient to separate doses by 2 hours
- Dispense with a blood pressure monitoring plan
Correct answer: Contact the prescriber — concurrent use is absolutely contraindicated due to severe hypotension risk
PDE5 inhibitors combined with nitrates cause a potentially fatal synergistic hypotensive effect and are absolutely contraindicated together.
Question 2: According to DHA pharmacy standards, what is the minimum record retention period for prescription records in Dubai?
- 1 year
- 3 years
- 5 years (Correct answer)
- 10 years
Correct answer: 5 years
DHA regulations require pharmacy prescription records to be retained for a minimum of 5 years for audit and regulatory compliance purposes.
Question 3: A patient on phenytoin is started on fluconazole. What pharmacokinetic interaction should the pharmacist anticipate?
- Fluconazole induces CYP2C9, lowering phenytoin levels
- Fluconazole inhibits CYP2C9, increasing phenytoin levels and toxicity risk (Correct answer)
- No significant interaction exists between these agents
- Fluconazole reduces phenytoin absorption from the GI tract
Correct answer: Fluconazole inhibits CYP2C9, increasing phenytoin levels and toxicity risk
Fluconazole is a potent CYP2C9 inhibitor, which decreases phenytoin metabolism and can cause toxic phenytoin levels.
Question 4: Which of the following is the correct technique for dispensing cytotoxic medications in a DHA-licensed pharmacy?
- Preparation on any clean counter with gloves only
- Preparation in a dedicated biological safety cabinet (BSC) with appropriate PPE (Correct answer)
- Preparation in any negative-pressure room
- Preparation by any staff member with a pharmacy degree
Correct answer: Preparation in a dedicated biological safety cabinet (BSC) with appropriate PPE
Cytotoxic drugs must be prepared in a validated biological safety cabinet with full PPE (gloves, gown, mask) to protect staff from hazardous exposure.
Question 5: A 70-year-old patient taking digoxin develops nausea, visual disturbances, and bradycardia. The serum digoxin level is 3.2 ng/mL. What is the most appropriate immediate action?
- Reduce digoxin dose by half and recheck levels in one week
- Hold digoxin, notify the physician immediately, and prepare for potential digoxin-specific antibody (Fab) therapy (Correct answer)
- Administer activated charcoal and continue digoxin at a lower dose
- Increase potassium supplementation and continue digoxin
Correct answer: Hold digoxin, notify the physician immediately, and prepare for potential digoxin-specific antibody (Fab) therapy
A digoxin level above the therapeutic range (0.5–2 ng/mL) with toxicity symptoms (GI, visual, cardiac) requires immediate drug cessation, physician notification, and potential Fab antidote administration.
Question 6: Under UAE regulations, which of the following is a requirement before dispensing a prescription-only medication (POM) without a prescription in an emergency?
- Verbal authorization from any nurse is sufficient
- The pharmacist may dispense a limited emergency supply and must obtain a valid prescription within 72 hours (Correct answer)
- POMs can never be dispensed without a written prescription under any circumstances
- Dispensing is allowed freely if the patient claims they are a healthcare worker
Correct answer: The pharmacist may dispense a limited emergency supply and must obtain a valid prescription within 72 hours
UAE health regulations allow pharmacists to supply a limited emergency quantity of a POM without a prescription, provided a valid prescription is obtained within 72 hours.
Question 7: What is the primary reason metronidazole should not be combined with alcohol or alcohol-containing products?
- Alcohol reduces metronidazole's antibacterial spectrum
- Metronidazole inhibits aldehyde dehydrogenase, causing a disulfiram-like reaction (Correct answer)
- Alcohol increases metronidazole renal clearance, reducing efficacy
- The combination causes severe hepatotoxicity within 24 hours
Correct answer: Metronidazole inhibits aldehyde dehydrogenase, causing a disulfiram-like reaction
Metronidazole inhibits aldehyde dehydrogenase, causing acetaldehyde accumulation when alcohol is consumed, leading to flushing, nausea, tachycardia, and hypotension (disulfiram-like reaction).
DHA Pharmacy & Medication Management 5
A patient taking sildenafil for erectile dysfunction is prescribed isosorbide mononitrate for angina.
What is the pharmacist's correct action?