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:
How this interaction occurs is not known.
What might happen:
Hormonal contraceptive products (such as "the pill", the "mini-pill", Norplant, birth control injections, and the patch) may not prevent you from becoming pregnant while you are taking telaprevir. Telaprevir is used with another medicine, ribavirin, which may cause birth defects.
What you should do about this interaction:
You should not rely on a hormonal contraceptive agent as your method of birth control while taking telaprevir. Discuss birth control options with the doctor that prescribed telaprevir for you and with your gynecologist (OB/GYN). You should use two other methods of birth control (such as an intrauterine device [IUD] and/or barrier methods) while taking telaprevir and ribavirin and for six months after finishing your therapy. Be sure to undergo a pregnancy test every month. If you think that you may be pregnant, contact your doctor right away.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.
1.Incivek (telaprevir) US prescribing information. Vertex Pharmaceuticals Incorporated October, 2013.
2.Garg V, van Heeswijk R, Yang Y, Kauffman R, Smith F, Adda N. The Pharmacokinetic Interaction Between an Oral Contraceptive Containing Ethinyl Estradiol and Norethindrone and the HCV Protease Inhibitor Telaprevir. J Clin Pharmacol 2011 Oct 30.