Drug Interactions between ethinyl estradiol and Viekira XR

Ritonavir may reduce the blood levels and effects of ethinyl estradiol. If you are using birth control pills or another hormone-type contraceptive such as a patch, shot, vaginal ring or implant, you should talk to your doctor before taking ritonavir. You may need an alternative or additional method of birth control during and for at least two weeks after treatment with ritonavir in order to avoid an unintended pregnancy. Let your doctor know if you experience bleeding outside of your menstrual cycle, since it may indicate reduced effectiveness of ethinyl estradiol. 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.

CONTRAINDICATED: Coadministration of ethinyl estradiol-, mestranol-, or estetrol-containing products may increase the risk of liver enzyme elevations associated with the use of ombitasvir/paritaprevir/ritonavir, with or without dasabuvir. The proposed mechanism is the inhibition of UDP-glucuronosyltransferase (UGT) by ombitasvir, paritaprevir, and dasabuvir. During clinical trials, approximately 1% of all subjects experienced post-baseline serum ALT levels greater than 5 times the upper limit of normal (ULN) after starting treatment, with or without ribavirin. However, the incidence increased to 25% (4/16) among women taking a concomitant medication containing ethinyl estradiol. The incidence of clinically relevant ALT elevations among women using estrogens other than mestranol or ethinyl estradiol, such as estradiol and conjugated estrogens used in hormone replacement therapy, was 3% (2/59). In general, ALT elevations were asymptomatic, occurred during the first 4 weeks of treatment (mean 20 days; range 8 to 57 days), and declined within two to eight weeks of onset despite continued therapy. Elevations in ALT were typically not associated with bilirubin elevations, and cirrhosis was not a risk factor. Data are not available for estetrol but the possibility of a similar interaction should be considered.

MANAGEMENT: Ethinyl estradiol-, mestranol-, or estetrol-containing medications must be discontinued prior to starting therapy with ombitasvir/paritaprevir/ritonavir, with or without dasabuvir. Alternative contraception such as progestin-only contraceptives or non-hormonal methods are recommended. Ethinyl estradiol-, mestranol-, or estetrol-containing medications can be restarted approximately 2 weeks following completion of the hepatitis C treatment. Liver function tests should be performed on all patients during the first 4 weeks of treatment and as clinically indicated thereafter. If ALT is elevated above baseline at any time during treatment, the test should be repeated and monitored closely. Therapy should be discontinued if ALT levels remain persistently greater than 10 times the ULN, or if ALT elevations are accompanied by signs or symptoms of liver inflammation or increasing conjugated bilirubin, alkaline phosphatase, or INR. Patients should be advised to seek medical attention if they experience potential signs and symptoms of hepatotoxicity such as fever, rash, itching, anorexia, nausea, vomiting, fatigue, malaise, right upper quadrant pain, dark urine, pale stools, and jaundice.

Using ethinyl estradiol together with paritaprevir is not recommended. Products containing ethinyl estradiol, mestranol, or estetrol may increase the risk of liver problems associated with the use of paritaprevir. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact. You should seek immediate medical attention if you develop fever, chills, joint pain or swelling, unusual bleeding or bruising, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, dark colored urine, light colored stools, and/or yellowing of the skin or eyes, as these may be signs and symptoms of liver damage. You may resume using ethinyl estradiol two weeks after completing paritaprevir. 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.

Using ethinyl estradiol together with dasabuvir is not recommended. Products containing ethinyl estradiol, mestranol, or estetrol may increase the risk of liver problems associated with the use of dasabuvir. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact. You should seek immediate medical attention if you develop fever, chills, joint pain or swelling, unusual bleeding or bruising, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, dark colored urine, light colored stools, and/or yellowing of the skin or eyes, as these may be signs and symptoms of liver damage. You may resume using ethinyl estradiol two weeks after completing dasabuvir. 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.