What antibiotic prophylaxis is required for a patient with a history of deep vein thrombosis?

Correct answer: A. None

• A. CORRECT. Deep vein thrombosis is a venous thromboembolic condition. It is not among the cardiac conditions for which the American Heart Association suggests endocarditis prophylaxis, and no antibiotic is indicated.
• B. Clindamycin is no longer recommended for endocarditis prophylaxis at all under the 2021 AHA statement, and prophylaxis is not indicated here in any case.
• C. Amoxicillin 2 g is the standard regimen, but only for patients who meet the cardiac criteria — which this patient does not.
• D. Cephalexin 2 g is a penicillin-allergy alternative, again only where prophylaxis is genuinely indicated.

Note: The real management question with a DVT history is ANTICOAGULATION, not antibiotics. Find out whether the patient is on warfarin (check a recent INR, treat if under 3.5 for routine procedures) or a DOAC such as apixaban or rivaroxaban (usually no interruption for routine dentistry; consider timing the appointment for the trough). Manage bleeding locally rather than by stopping the drug.