Birth control pills and other medications

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Birth control pills and other medications

Some medications can interfere with how birth control pills work. For example, you may not be protected from pregnancy while you are taking other medications that affect liver metabolism. The vaginal ring and skin patch contain combination hormones and may also interact with some medications. Discuss this with your health professional.

The following medications can reduce the effectiveness of birth control pills. Use another method of birth control when you are taking:

• The herbal medication St. John's wort.¹
• Certain antibiotics such as rifampin (Rifadin) and griseofulvin (Fulvicin). Other antibiotics, such as penicillins (ampicillin, amoxicillin), tetracyclines, or metronidazole (Flagyl), do not change the effectiveness of birth control pills.²
• Anticonvulsants, such as carbamazepine (Tegretol), phenobarbital, phenytoin (Dilantin), and primidone (Mysoline).
• Narcolepsy medications, such as modafinil (Provigil).
• Antiretroviral protease inhibitors used to treat HIV, such as Ritonavir.

Birth control pills may decrease the effectiveness of the following medications. An increased dose of the medication may be needed.

• Salicylates (aspirin products)
• Antiviral medications, such as nevirapine (Viramune)

Birth control pills may increase the effectiveness of the following medications. A decreased dose of the medication may be needed.

• Benzodiazepines, such as Valium
• Beta-blockers, such as Inderal
• Corticosteroids, such as prednisone
• Theophylline, such as Theodur
• Tricyclic antidepressants, such as Elavil

If you are using birth control pills and taking other medications, talk with your health professional about all the medications you use.

Birth control pills may increase your sensitivity to the effects of caffeine.

References

Citations

1. Hatcher RA, Nelson A (2004). Combined hormonal contraceptive methods. In RA Hatcher et al., eds., Contraceptive Technology, 18th ed., pp. 391–460. New York: Ardent Media.

2. American College of Obstetricians and Gynecologists (2000). The use of hormonal contraception in women with coexisting medical conditions. ACOG Practice Bulletin No. 18. Obstetrics and Gynecology, 96(1): 1–13.

Credits

Last updated:	May 23, 2006
Author:	Merrill Hayden
Reviewed By:	Joy Melnikow, MD, MPH - Family Medicine, Kirtly Jones, MD - Obstetrics and Gynecology
Editors:	Kathleen M. Ariss, MS, Terrina Vail