American Board of Internal Medicine (ABIM) Certification Practice Exam

What is a relative contraindication to the use of colchicine?

1. Use of allopurinol

2. Use of diltiazem

3. Use of NSAIDs

4. Use of corticosteroids

The correct answer is: Use of diltiazem

Colchicine is a medication commonly used to treat gout and is known for its mechanism in disrupting the inflammatory response. While it has several uses, there are certain interactions and contraindications to consider when prescribing it. The use of diltiazem, a calcium channel blocker, is considered a relative contraindication to colchicine because diltiazem can inhibit the metabolism of colchicine through the cytochrome P450 system, particularly CYP3A4. When diltiazem is administered alongside colchicine, there is an increased risk of colchicine toxicity due to elevated serum levels, which can lead to serious side effects such as gastrointestinal distress, myopathy, and potentially fatal complications. This interaction is critical to be aware of, especially in patients who may already have compromised renal function or other risk factors for colchicine toxicity. Other medications listed, including allopurinol, NSAIDs, and corticosteroids, can generally be used in conjunction with colchicine, but care should be taken with dosages and patient-specific factors. For instance, while NSAIDs and corticosteroids may complement the anti-inflammatory effects of colchicine in gout management, allopurinol is typically used for chronic management of hyperuricemia and can be safely prescribed but usually not