or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.fexinidazoleSerious - Use Alternative (1)fexinidazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates. fezolinetantContraindicated (1)conjugated estrogens will increase the level or effect of fezolinetant by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated. Fezolinetant AUC and peak plasma concentration are increased if coadministered with drugs that are weak, moderate, or strong CYP1A2 inhibitorsfleroxacinMonitor Closely (1)fleroxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.fluconazoleMonitor Closely (1)fluconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fludrocortisoneMonitor Closely (1)fludrocortisone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.folic acidMinor (1)conjugated estrogens decreases levels of folic acid by altering metabolism. Minor/Significance Unknown.fondaparinuxSerious - Use Alternative (1)conjugated estrogens decreases effects of fondaparinux by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.fosamprenavirMonitor Closely (1)fosamprenavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fosaprepitantMonitor Closely (1)fosaprepitant will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fosfomycinMonitor Closely (1)fosfomycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.fosphenytoinMonitor Closely (2)fosphenytoin will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. fosphenytoin will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.gemifloxacinMonitor Closely (1)gemifloxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.gentamicinMonitor Closely (1)gentamicin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.givosiranSerious - Use Alternative (1)givosiran will increase the level or effect of conjugated estrogens by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP1A2 substrates with givosiran. If unavoidable, decrease the CYP1A2 substrate dosage in accordance with approved product labeling.grapefruitMonitor Closely (1)grapefruit will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.griseofulvinMonitor Closely (1)griseofulvin will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.heminMonitor Closely (1)conjugated estrogens decreases effects of hemin by pharmacodynamic antagonism. Use Caution/Monitor. Drugs that increase delta-aminolevulinic acid synthetase may decrease hemin effect.heparinSerious - Use Alternative (1)conjugated estrogens decreases effects of heparin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.hyaluronidaseMonitor Closely (1)conjugated estrogens decreases effects of hyaluronidase by Other (see comment). Use Caution/Monitor. Comment: Enhanced tissue resistance to hyaluronidase.hydrocortisoneMonitor Closely (1)hydrocortisone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.idelalisibSerious - Use Alternative (1)idelalisib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substratesimipramineMinor (1)conjugated estrogens, imipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.indinavirMonitor Closely (2)indinavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. indinavir will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.insulin degludecMonitor Closely (1)conjugated estrogens decreases effects of insulin degludec by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may impair glucose tolerance.insulin degludec/insulin aspartMonitor Closely (1)conjugated estrogens decreases effects of insulin degludec/insulin aspart by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may impair glucose tolerance.insulin inhaledMonitor Closely (1)conjugated estrogens decreases effects of insulin inhaled by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may impair glucose tolerance.isavuconazonium sulfateMonitor Closely (1)conjugated estrogens will decrease the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.isoniazidMinor (1)isoniazid will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.istradefyllineMonitor Closely (1)istradefylline will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.itraconazoleSerious - Use Alternative (1)itraconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.ivosidenibMonitor Closely (1)ivosidenib will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ketoconazoleMonitor Closely (2)ketoconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. ketoconazole will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.L-methylfolateMinor (1)conjugated estrogens decreases levels of L-methylfolate by altering metabolism. Minor/Significance Unknown.lamotrigineMonitor Closely (1)conjugated estrogens decreases levels of lamotrigine by increasing hepatic clearance. Use Caution/Monitor.lapatinibMonitor Closely (2)lapatinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. lapatinib will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.larotrectinibMinor (1)larotrectinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.lenacapavirMonitor Closely (1)lenacapavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir (a moderate CYP3A4 inhibitor) may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.levofloxacinMonitor Closely (1)levofloxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.levoketoconazoleMonitor Closely (2)levoketoconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. levoketoconazole will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.linezolidMonitor Closely (1)linezolid will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.liraglutideMonitor Closely (1)conjugated estrogens decreases effects of liraglutide by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may decrease hypoglycemic effects of antidiabetics by impairing glucose tolerance. Monitor for glycemic control in diabetic patients.lofepramineMinor (1)conjugated estrogens, lofepramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.lonapegsomatropinMonitor Closely (1)conjugated estrogens will decrease the level or effect of lonapegsomatropin by Other (see comment). Use Caution/Monitor. Oral estrogens may reduce serum insulin-like growth factor-1 response to lonapegsomatropin. Patients receiving oral estrogen replacement may require higher lonapegsomatropin dosages.lopinavirMonitor Closely (1)lopinavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.loratadineMonitor Closely (1)loratadine will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.lorlatinibSerious - Use Alternative (1)lorlatinib will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.lovastatinMonitor Closely (1)lovastatin will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.lumefantrineMonitor Closely (1)lumefantrine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.magnesium chlorideMinor (1)conjugated estrogens decreases levels of magnesium chloride by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.magnesium citrateMinor (1)conjugated estrogens decreases levels of magnesium citrate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.magnesium hydroxideMinor (1)conjugated estrogens decreases levels of magnesium hydroxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.magnesium oxideMinor (1)conjugated estrogens decreases levels of magnesium oxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.magnesium sulfateMinor (1)conjugated estrogens decreases levels of magnesium sulfate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.maprotilineMinor (1)conjugated estrogens, maprotiline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.maravirocMonitor Closely (1)conjugated estrogens increases levels of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .marijuanaMonitor Closely (1)marijuana will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.meropenemMonitor Closely (1)meropenem will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.meropenem/vaborbactamMonitor Closely (1)meropenem/vaborbactam will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.metforminMonitor Closely (1)conjugated estrogens decreases effects of metformin by pharmacodynamic antagonism. Use Caution/Monitor.methylprednisoloneMonitor Closely (1)methylprednisolone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.metronidazoleMonitor Closely (2)metronidazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. metronidazole will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.metyraponeMinor (1)conjugated estrogens decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.miconazole vaginalMonitor Closely (1)miconazole vaginal will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.mifepristoneMonitor Closely (1)mifepristone will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.minocyclineMonitor Closely (1)minocycline will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.mitotaneSerious - Use Alternative (1)mitotane will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.moxifloxacinMonitor Closely (1)moxifloxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.mycophenolateMinor (1)mycophenolate decreases effects of conjugated estrogens by unknown mechanism. Minor/Significance Unknown. Clinical significance unclear.nefazodoneMonitor Closely (1)nefazodone will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.nelfinavirMonitor Closely (1)nelfinavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.neomycin POMonitor Closely (1)neomycin PO will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.nevirapineMonitor Closely (1)nevirapine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.nicardipineMonitor Closely (1)nicardipine will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.nifedipineMonitor Closely (2)nifedipine will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. nifedipine will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.nilotinibMonitor Closely (2)nilotinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. nilotinib will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.nitrofurantoinMonitor Closely (1)nitrofurantoin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.nortriptylineMinor (1)conjugated estrogens, nortriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.ofloxacinMonitor Closely (1)ofloxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.ospemifeneContraindicated (1)ospemifene, conjugated estrogens. Either increases effects of the other by pharmacodynamic synergism. Contraindicated.oxcarbazepineMonitor Closely (1)oxcarbazepine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.oxytetracyclineMonitor Closely (1)oxytetracycline will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.pacritinibSerious - Use Alternative (1)conjugated estrogens