Interactions between cycrin(medroxyPROGESTERone) and Atazanavir (atazanavir)
medroxyPROGESTERone and atazanavir (Moderate Drug-Drug)
GENERALLY AVOID: Coadministration with atazanavir may increase the plasma concentrations of ethinyl estradiol and norethindrone and possibly other contraceptive hormones. The mechanism is atazanavir inhibition of CYP450 3A4 and UGT1A1, the enzymes responsible for the metabolic clearance of contraceptive hormones. In 19 study subjects, atazanavir (400 mg once a day for 14 days) increased the mean steady-state peak plasma concentration (Cmax), area under the concentration-time curve (AUC) and trough plasma concentration (Cmin) of ethinyl estradiol (Ortho-Novum 7/7/7) by 15%, 48% and 91%, respectively, compared to administration of the oral contraceptive alone. The Cmax, AUC and Cmin of norethindrone were increased by 67%, 110% and 262%, respectively. Decreased HDL or increased insulin resistance may be associated with elevated plasma concentrations of norethindrone.
MANAGEMENT: The manufacturer recommends alternate methods of nonhormonal contraception during atazanavir or atazanavir-ritonavir therapy.
