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Study after study shows that there are no clinically significant drug interactions* between the vast majority of antibiotics and the Birth Control pill. Anecdotal evidence from health care providers has led some to recommend using a backup method of birth control for a week after using antibiotics. Long-term use (as for acne) does not increase the risk of pregnancy. There are a few antibiotics, such as rifampin and griseofulvin and some HIV medications, that do interact. The safest approach is to check with your health care provider or pharmacist for advice specific to your situation.
*While some antibiotics may slightly change the absorption of estrogen in the gut, these changes are not enough to change how well the birth control pill works, with the exceptions noted above.
Taken from the newsletter: "Pharmacist's Letter" November 11, 2002
TRUTH:
Women have been warned for decades to use backup contraception when taking oral contraceptives and antibiotics together.
This all started back in the '70s when a few women on oral contraceptives took rifampin and then got pregnant.
Additional anecdotal reports started popping up, suggesting that other antibiotics might be related to unwanted pregnancies in women taking oral contraceptives.
One theory was that antibiotics killed gut bacteria, which are involved in estrogen absorption.
Researchers later discovered that rifampin and griseofulvin actually increase the metabolism of oral contraceptives, making them less effective.
But the evidence for other antibiotics is shaky.
In fact, oral contraceptive levels are not DECREASED by most antibiotics...tetracycline, doxycycline, ampicillin, quinolones, and metronidazole.
Oral contraceptive levels are actually INCREASED by some antibiotics...erythromycin...clarithromycin...and trimethoprim-sulfamethoxazole.
There's growing evidence that most women taking antibiotics with oral contraceptives do NOT have an increased risk of getting pregnant.
But most package inserts still warn that another form of contraception is needed when starting antibiotics.
Explain to women taking oral contraceptives that there can be up to a 3% failure rate, regardless of antibiotic use.
A small number of women might be predisposed to a higher failure rate due to genetic metabolic variations...but it's difficult to determine who these women are.
To be on the safe side, tell women to continue using backup contraception during the entire course of antibiotics and for 7 days after.
Explain that sickness or antibiotic side effects such as diarrhea or vomiting can increase oral contraceptive failure.
What else can I help you with?
Does penicillin affect birth control?
Penicillin does not affect birth control.
Does Motrin IB affect birth control pills?
Asprin doesn't affect birth control.
Does cortisone affect the birth control pill?
Cortisone does not affect how well the birth control pill works.
Does augmentin affect the birth control pill?
Augmentin does not affect how well the birth control pill works.
Does topical Clindamycin affect the birth control pill?
No, clindamycin topical for acne does not affect the birth control pill
Do antibiotics affect the mesigyna birth control shot?
Antibiotics rarely affect the birth control pill in general.
Can glass affect birth control?
I can't think of any way that glass would affect birth control.
Does caffeine affect birth control?
Caffeine does not affect how well birth control works. Thank goodness!
How does the consumption of stevia affect the effectiveness of birth control methods?
Consuming stevia does not affect the effectiveness of birth control methods.
Does Hydrocortisone affect the birth control pill?
Nasacort and other inhaled steroids do not affect the birth control pill
Does acidophilus affect birth control?
no
Does Zyban affect birth control?
no
