trimethoprim--sulfamethoxazole-drug-combination and Atrial-Fibrillation

Topics: Anti-Infective Agents; Atrial Fibrillation; Ceftriaxone; Cell Transformation, Neoplastic; Coronary Artery Disease; Diagnosis, Differential; Humans; Hyperlipidemias; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphoma; Male; Middle Aged; Neoplasm Recurrence, Local; Nocardia Infections; Seizures; Smoking; Trimethoprim, Sulfamethoxazole Drug Combination

The following report illustrates a case of trimethoprim/sulfamethoxazole-induced hypoprothrombinemia in a patient receiving ongoing warfarin therapy for atrial fibrillation and aortic valve replacement. He was treated with trimethoprim/sulfamethoxazole (TMP/SMX) for sinusitis. During this time, the patient's prothrombin time international normalized ratio (INR) increased 3.5 times higher than the baseline value. The INR values decreased when the antibiotic was discontinued. If a patient is on warfarin and TMP/SMX is added, INR values should be monitored closely.

Topics: Aged; Aortic Valve; Atrial Fibrillation; Drug Interactions; Heart Valve Prosthesis; Humans; Hypoprothrombinemias; Male; Prothrombin Time; Sinusitis; Trimethoprim, Sulfamethoxazole Drug Combination; Warfarin