Some medicines can interfere with how
birth control pills work. For example, you may not be
protected from pregnancy while you are taking other medicines that affect liver
metabolism. The vaginal ring and skin patch contain combination hormones and
may also interact with some medicines. The progestin-only pills, implant
(Implanon), and shot (Depo-Provera) also contain hormones that may interact
with some medicines.
Taking medicines while you
are using hormonal birth control may increase your risk of problems. Some
combinations of medicine may affect the birth control hormones in your body,
making them too strong or too weak. This may increase your chance of getting
pregnant. Or a new medicine may be less likely to work because you have birth
control hormones in your body. Talk with your doctor or pharmacist to make sure
that any medicines you take are not causing problems when you are using
hormonal birth control.
Birth control pills may increase your sensitivity
to the effects of caffeine.