citrate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.magnesium hydroxideMinor (1)estradiol decreases levels of magnesium hydroxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.magnesium oxideMinor (1)estradiol decreases levels of magnesium oxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.magnesium sulfateMinor (1)estradiol decreases levels of magnesium sulfate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.maprotilineMinor (1)estradiol, maprotiline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.marijuanaMonitor Closely (1)marijuana will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.meropenemMonitor Closely (1)meropenem will decrease the level or effect of estradiol 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 estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.metforminMonitor Closely (1)estradiol decreases effects of metformin by pharmacodynamic antagonism. Use Caution/Monitor.methylprednisoloneMonitor Closely (1)methylprednisolone will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.metronidazoleMonitor Closely (2)metronidazole will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. metronidazole will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.metyraponeMinor (1)estradiol decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.miconazole vaginalMonitor Closely (1)miconazole vaginal will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.mifepristoneMonitor Closely (1)mifepristone will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.minocyclineMonitor Closely (1)minocycline will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.mitotaneMonitor Closely (1)mitotane decreases levels of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.moxifloxacinMonitor Closely (1)moxifloxacin will decrease the level or effect of estradiol 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 estradiol by unknown mechanism. Minor/Significance Unknown. Clinical significance unclear.nafcillinMonitor Closely (2)nafcillin will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. nafcillin will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.nefazodoneMonitor Closely (1)nefazodone will increase the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)nefazodone will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.nelfinavirMonitor Closely (1)nelfinavir will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.neomycin POMonitor Closely (1)neomycin PO will decrease the level or effect of estradiol 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 estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.nicardipineMonitor Closely (1)nicardipine will increase the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.nifedipineMonitor Closely (2)nifedipine will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. nifedipine will decrease the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.nilotinibMonitor Closely (2)nilotinib will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. nilotinib will increase the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.nitrofurantoinMonitor Closely (1)nitrofurantoin will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.nortriptylineMinor (1)estradiol, 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 estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.ospemifeneContraindicated (1)ospemifene, estradiol. Either increases effects of the other by pharmacodynamic synergism. Contraindicated.oxcarbazepineMonitor Closely (1)oxcarbazepine will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.oxytetracyclineMonitor Closely (1)oxytetracycline will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.pacritinibSerious - Use Alternative (1)estradiol will decrease the level or effect of pacritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.paromomycinMonitor Closely (1)paromomycin will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.pentobarbitalMonitor Closely (1)pentobarbital will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.phenindioneSerious - Use Alternative (1)estradiol decreases effects of phenindione by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.phenobarbitalMonitor Closely (2)phenobarbital will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. phenobarbital will decrease the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.phenytoinMonitor Closely (2)phenytoin will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. phenytoin will decrease the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.phytoestrogensMinor (1)phytoestrogens decreases effects of estradiol by pharmacodynamic antagonism. Minor/Significance Unknown.pivmecillinamMonitor Closely (1)pivmecillinam will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.pleurisy rootMinor (1)pleurisy root decreases effects of estradiol by unspecified interaction mechanism. Minor/Significance Unknown. Theoretical interaction.ponatinibMonitor Closely (1)ponatinib increases levels of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.posaconazoleMonitor Closely (1)posaconazole will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.prednisoneMonitor Closely (1)prednisone will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.primidoneMonitor Closely (1)primidone will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.protamineSerious - Use Alternative (1)estradiol decreases effects of protamine by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.protriptylineMinor (1)estradiol, protriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.pyridoxineMinor (1)estradiol decreases levels of pyridoxine by altering metabolism. Minor/Significance Unknown.pyridoxine (Antidote)Minor (1)estradiol decreases levels of pyridoxine (Antidote) by altering metabolism. Minor/Significance Unknown.quercetinMonitor Closely (1)quercetin will decrease the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.quinidineSerious - Use Alternative (1)quinidine will increase the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.quinupristin/dalfopristinMonitor Closely (2)quinupristin/dalfopristin will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. quinupristin/dalfopristin will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.ranolazineMonitor Closely (1)ranolazine will increase the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.ribociclibMonitor Closely (1)ribociclib will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.rifabutinSerious - Use Alternative (1)rifabutin will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.rifampinMonitor Closely (1)rifampin will decrease the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)rifampin will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.rifapentineMonitor Closely (1)rifapentine will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ritonavirMonitor Closely (2)ritonavir will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. ritonavir will increase the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.ropiniroleMinor (1)estradiol increases levels of ropinirole by unspecified interaction mechanism. Minor/Significance Unknown.rose hipsMinor (1)estradiol decreases levels of rose hips by increasing elimination. Minor/Significance Unknown.roxithromycinMonitor Closely (1)roxithromycin will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.rufinamideMonitor Closely (1)rufinamide will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.secobarbitalMonitor Closely (1)secobarbital will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.simvastatinMonitor Closely (1)simvastatin will increase the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.sirolimusMonitor Closely (1)sirolimus will increase the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.somapacitanMonitor Closely (1)estradiol decreases effects of somapacitan by Other (see comment). Modify Therapy/Monitor Closely. Comment: Oral estrogens may reduce the serum IGF-1 response to somapacitan. Patients may require higher somapacitan dosages. See drug monograph for starting dose recommendations.St John's WortMonitor Closely (1)St John's Wort will decrease the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Serious - Use Alternative (1)St John's Wort will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.stiripentolMonitor Closely (1)stiripentol, estradiol. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP1A2 inhibitor and inducer. Monitor CYP1A2 substrates coadministered with stiripentol for increased or decreased effects. CYP1A2 substrates may require dosage adjustment.streptomycinMonitor Closely (1)streptomycin will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.sulfadiazineMonitor Closely (1)sulfadiazine will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.sulfamethoxazoleMonitor Closely (1)sulfamethoxazole will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.sulfisoxazoleMonitor Closely (1)sulfisoxazole will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.tacrolimusMonitor Closely (1)tacrolimus will increase the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.tazemetostatMonitor Closely (1)tazemetostat will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tecovirimatMonitor Closely (1)tecovirimat will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.teicoplaninMonitor Closely (1)teicoplanin will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.temocillinMonitor Closely (1)temocillin will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.teriflunomideMonitor Closely (1)teriflunomide decreases levels of estradiol by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.tetracyclineMonitor Closely (1)tetracycline will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.ticarcillinMonitor Closely (1)ticarcillin will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.tigecyclineMonitor Closely (1)tigecycline will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.tobramycinMonitor Closely (1)tobramycin will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.tolvaptanMonitor Closely (1)tolvaptan will increase the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.topiramateMonitor Closely (1)topiramate will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.trazodoneMonitor Closely (1)trazodone will decrease the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.Minor (1)estradiol, trazodone. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.trimethoprimMonitor Closely (1)trimethoprim will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.trimipramineMinor