Drug Interactions between boceprevir and Premphase 14/14

Boceprevir may reduce the blood levels and effects of medroxyPROGESTERone, which may make it less reliable as a form of birth control. You may continue to use medroxyPROGESTERone if desired, but two alternative, non-hormonal methods of birth control should be used during and for two weeks after treatment with boceprevir to avoid unintended pregnancy. This is particularly important because one of the other hepatitis C medications that you must use, ribavirin, is known to cause major birth defects or even death in the unborn child. Examples of non-hormonal methods of birth control include: a male condom with spermicidal jelly OR a female condom with spermicidal jelly--a combination of a male condom and a female condom is not suitable; a diaphragm with spermicidal jelly; a cervical cap with spermicidal jelly; or an intrauterine device (IUD). Talk to your gynecologist or other healthcare professional for help in selecting effective methods of birth control that work best for you. If you take hormone replacement for menopause, you should contact your doctor if you experience increased frequency or worsening of your symptoms such as hot flashes, vaginal dryness, or abnormal bleeding. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Consumer information for this interaction is not currently available.

MONITOR: Coadministration with the hepatitis C virus (HCV) NS3/4A protease inhibitors, boceprevir and telaprevir, may decrease the plasma concentrations and efficacy of estrogens used for hormonal replacement therapy. The mechanism involves induction of CYP450 3A4, the isoenzyme primarily responsible for the metabolic clearance of sex hormones. When an oral contraceptive containing drospirenone-ethinyl estradiol (3 mg-0.02 mg daily for 14 days) was given in combination with boceprevir (800 mg three times daily for 7 days), ethinyl estradiol systemic exposure (AUC) decreased by approximately 25%, with no change in the peak plasma concentration (Cmax). In a study of 24 subjects who were administered an oral contraceptive containing ethinyl estradiol-norethindrone (0.035 mg-0.5 mg daily) concomitantly with telaprevir (750 mg every 8 hours) for 21 days, the Cmax and AUC of ethinyl estradiol decreased by 26% and 28%, respectively. In addition, there was a 33% reduction in the trough plasma concentration (Cmin) of ethinyl estradiol.

MANAGEMENT: Dosage adjustments as well as increased clinical and laboratory monitoring for estrogen deficiency should be considered whenever boceprevir or telaprevir is used concomitantly with estrogens used for hormonal replacement therapy.