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A member asked:

How long does bactrim (sulfamethoxazole and trimethoprim) stay in your system?

A doctor has provided 1 answer
Dr. Michael Ein answered

Specializes in Infectious Disease

55 hours: Bactrim (sulfamethoxazole and trimethoprim) contains trimethoprim and sulfamethoxazole. The half life of trimethoprim (time to elimination of half the drug) is 10 hours in healthy people. The half life of sulfamethoxazole is 11 hours in the healthy. A drug is considered eliminated 5 half lives after the last dose was taken. Therefore Bactrim (sulfamethoxazole and trimethoprim) would be eliminated about 55 hours after taking the last dose.

Answered 6/22/2020

4.8k views

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