Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
When these two medicines are taken together, your body may process estrogen faster.
What might happen:
The effects of your birth control pills may decrease and cause breakthrough bleeding, spotting, or pregnancy. The effects of your estrogen replacement therapy may decrease. The effects of the interaction may last for several weeks after you stop taking rifampin.
What you should do about this interaction:
Talk to your healthcare professional (e.g. doctor, pharmacist) as soon as possible about using a different form of birth control. Contact your doctor if you experience breakthrough bleeding, spotting, or pregnancy.If you are taking estrogen-replacement therapy, let your doctor know if you have any menopausal symptoms.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
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