It has been discovered that the antibiotic, Rifampin, rarely used for anything aside from TB, does interfere with the effectiveness of oral contraceptives. This caused us to become concerned that perhaps all antibiotics could have this effect and warnings were issues. Since that time, however, it has been generally accepted that it is a rare event, occurring pretty much with Rifampin only.
Theoretically, other antibiotics, particularly penicillin and tetracycline derivatives, could impair the effectiveness of birth control pills, but no large studies have proved such an effect.
It is possible that some women could be affected by an interaction but as a whole the fear has been considered to be overstated. Of course if you are determined NOT to get pregnant, such advice (using a barrier method for the week) would always be the safest course. In your case, I would not be alarmed.
The answers in online forums are for information only and are not intended to substitute for medical advice and care. Please see your personal health care provider for further evaluation of your individual case.
Debbie Miller, RN