DRUG INTERACTIONS: Certain drugs can decrease the effectiveness of combination-type birth control pills by decreasing the amount of birth control pill hormones in your system (impaired enterohepatic recirculation or hepatic induction). This can result in pregnancy. Consult your doctor or pharmacist for details. Drugs that may cause this effect include: many antibiotics (e.g., cephalosporins, chloramphenicol, macrolides, penicillins, tetracyclines, sulfas), aprepitant, bexarotene, bosentan, dapsone, griseofulvin, certain HIV protease inhibitors (e.g., amprenavir, nelfinavir, ritonavir), modafinil, nevirapine, rifamycins (e.g., rifampin), many seizure medications (e.g., barbiturates, carbamazepine, phenytoin, primidone, topiramate), St. John's wort. Ask your doctor if you should use additional reliable birth control methods while taking any of the drugs mentioned above while also taking birth control pills. Before taking this medication, tell your doctor or pharmacist of all prescription and non-prescription medications you may use, especially of: thyroid hormone drugs, certain benzodiazepines (e.g., diazepam, chlordiazepoxide), prednisone-like drugs, certain antidepressants (e.g., tricyclics), beta-blockers (e.g., metoprolol), "blood thinners" (anticoagulants such as warfarin), insulin. This product can affect the results of certain lab tests (e.g., thyroid). Inform all laboratory personnel that you use this drug. Birth control pills may significantly intensify the effects of alcohol. Consult your doctor or pharmacist about this. Do not start or stop any medicine without doctor or pharmacist approval.

OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US national poison hotline at 1-800-222-1222. Canadian residents should call their local poison control center directly. Symptoms of overdose may include nausea and vomiting. Females may experience vaginal bleeding.