NAPLEX (North American Pharmacist Licensure Examination) Practice Exam

Disable ads (and more) with a membership for a one time $4.99 payment

Ace your North American Pharmacist Licensure Examination (NAPLEX) with our comprehensive practice test. Features include interactive flashcards, multiple-choice questions, with detailed hints and explanations. Fast-track your pharmacy career today!

Practice this question and more.


Which side effect is associated with Bactrim (sulfamethoxazole/trimethoprim)?

  1. QT prolongation

  2. Increased INR with warfarin

  3. Infusion reaction

  4. Myopathy

The correct answer is: Increased INR with warfarin

Bactrim (sulfamethoxazole/trimethoprim) is known to interact with warfarin, leading to an increase in INR (International Normalized Ratio). Warfarin is a commonly used anticoagulant medication, and when taken concomitantly with Bactrim, it can potentiate the effects of warfarin, resulting in an increased risk of bleeding. Monitoring of INR levels is crucial when these medications are used together to prevent complications related to overanticoagulation. This is why the correct answer is B. The other options are not typically associated with Bactrim: - A. QT prolongation is a potential side effect of certain antibiotics like macrolides and quinolones, but not commonly seen with Bactrim. - C. Infusion reactions are more common with medications given intravenously rather than orally, and Bactrim is usually administered orally. - D. Myopathy is not a commonly reported side effect of Bactrim; however, muscle-related side effects may occur rarely in some individuals.