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A 37-year-old member asked:

Can the antibiotic "bactrim" affect my birth control pills in any way?

1 doctor answer1 doctor weighed in
Dr. David Krulak
Family Medicine 23 years experience
Bactrim (sulfamethoxazole and trimethoprim): This medication may actually increase plasma levels of ethinyl estradiol, the medicine found in many contraceptives.

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Similar questions

A 47-year-old member asked:

How long will antibiotics affect my birth control pills?

1 doctor answer1 doctor weighed in
Dr. CESAR HOLGADO
Obstetrics and Gynecology 39 years experience
Antibiotics: Some antibiotics decrease effectivity of birth control pills. This means that you have to use caution and protection for the rest of month that you are on antibiotics. The next month or cycle on birth contol pills should provide adequate coverage as long as you are not on antibiotics.
A 37-year-old member asked:

Can antibiotics really affect the effectiveness of birth control pills?

1 doctor answer2 doctors weighed in
Dr. Cornelia Franz
Specializes in Pediatrics
Yes: They affect absorption...Reducing absorption so pills are not as effective.
MA
A 21-year-old member asked:

Is azithormycin a known antibiotic to affect birth control pills?

2 doctor answers4 doctors weighed in
Dr. Oscar Novick
Pediatrics 58 years experience
Azithromycin: This antibiotic is not known to interact with birth control pills
A 34-year-old member asked:

What is it about antibiotics that causes birth control pills to be ineffective?

1 doctor answer1 doctor weighed in
Dr. Peter Karsant
Dentistry 39 years experience
Bacteria: The bacteria in your gut that make the pill effective by converting it from inactive to active form are killed off by antibiotics.
A 41-year-old member asked:

How long do birth control pills and antibiotics interact?

1 doctor answer1 doctor weighed in
Dr. Nicholas Fogelson
Specializes in Gynecology
Varies: There are only a few antibiotics that interfere with birth control pills, and fortunately they are rarely used. For antibiotics that do have an impact (rifampin, griseofulvin) effect though depends on when the antibiotics are taken in the cycle. The chemical effect is short, but if that short effect results in unintended ovulation, the impact may last the entire cycle.

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Last updated Jul 12, 2014

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