APC APC Drug Interactions and Contraindications

Question 1

Which combination is a well-known clinically significant drug interaction that can increase the risk of serotonin syndrome?

Accepted Answer

SSRIs and MAOIs

Answer

Combining SSRIs with MAOIs inhibits serotonin breakdown while increasing its release, leading to potentially fatal serotonin syndrome.

Question 2

Warfarin's anticoagulant effect is significantly enhanced when co-administered with which of the following?

Accepted Answer

Fluconazole

Answer

Fluconazole inhibits CYP2C9, the primary enzyme responsible for warfarin metabolism, thereby increasing warfarin plasma levels and bleeding risk.

Question 3

Methotrexate toxicity is significantly increased when given concurrently with which drug class?

Accepted Answer

NSAIDs

Answer

NSAIDs reduce renal clearance of methotrexate by inhibiting prostaglandin-dependent tubular secretion, leading to toxic accumulation.

Question 4

Which drug is absolutely contraindicated with sildenafil due to risk of severe hypotension?

Accepted Answer

Organic nitrates

Answer

Both sildenafil and organic nitrates increase cGMP levels, causing profound additive vasodilation and potentially fatal hypotension.

Question 5

In the APC competency framework, identifying drug-drug interactions requires the pharmacist to review which primary resource first?

Accepted Answer

Patient prescription history and current medication list

Answer

A complete current medication list is the essential starting point for identifying potential drug-drug interactions before dispensing.

(APC) Australian Pharmacy Council Practice Test