Seasonale is safe with most antibiotics.
However, there are certain antibiotics that either should definitely be avoided when on Seasonale (or users should seek a barrier method of contraception). These antibiotics have been proven to decrease the effectiveness of Seasonale in preventing ovulation and include:
-Rifabutin
-Rifampin
-Rifapentine
Other classes of antibiotics such as Clindamycin, Macrolides, Metranidazole, Nitrofurantoin, Penicillins, Quinolones, Sulfonamides, and Tetracyclines have been flagged with a caution as they MAY theoretically decrease the hormonal contraceptive’s efficacy. However, there have never been any proven cases to document a definitive decrease the effects of Seasonale.
But, if you are on Seasonale while taking an antibiotic, I would recommend using a barrier contraceptive during the course of the antibiotic just in case.