A number of medications including certain antibiotics decrease the levels of oral contraceptives in the blood. The actuaal decrease in the effectiveness of the oral contraceptive pill due to antibiotics has not been studied.
Because of a theoretical increased chances of pregnancy when using antibiotics with birth control pills, I would advise additional methods of protection like condoms.
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.