Nuvaring

See Contraindications. ALT elevations with HCV regimen ombitasvir/paritaprevir/ritonavir, with or without dasabuvir; discontinue Nuvaring prior to starting HCV regimen and restart 2wks after completion. Do not use with female barrier methods (eg, diaphragm, cervical cap, female condom); ring device may interfere with their placement and position. Antagonized by hepatic enzyme inducing drugs (eg, phenytoin, barbiturates, carbamazepine, bosentan, felbamate, griseofulvin, oxcarbazepine, rifampicin, topiramate, rifabutin, rufinamide, aprepitant, St. John's wort); use non-hormonal method or a backup contraception. May be potentiated by atorvastatin, acetaminophen, ascorbic acid, vaginal miconazole, or strong/moderate CYP3A4 inhibitors (eg, itraconazole, ketoconazole, voriconazole, fluconazole, grapefruit juice). May be affected by HIV/HCV protease inhibitors or NNRTIs. May antagonize acetaminophen, temazepam, salicylic acid, morphine, clofibric acid, lamotrigine. May potentiate cyclosporine, prednisolone, theophylline, tizanidine, voriconazole. May need dose adjustment of thyroid hormones. May affect lab tests (eg, coagulation factors, lipids, glucose tolerance, binding proteins, hormone binding globulins).