lamotrigine levels to decrease by almost 50%. Dose adjustment is required.lapatiniblapatinib will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.lenacapavirlenacapavir will increase the level or effect of estrogens esterified 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.levoketoconazolelevoketoconazole will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.levoketoconazole will increase the level or effect of estrogens esterified by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.liraglutideestrogens esterified 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.lonapegsomatropinestrogens esterified 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.lopinavirlopinavir will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.maravirocestrogens esterified increases levels of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .meropenem/vaborbactammeropenem/vaborbactam will decrease the level or effect of estrogens esterified by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.miconazole vaginalmiconazole vaginal will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.mifepristonemifepristone will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.mitotanemitotane decreases levels of estrogens esterified 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.nafcillinnafcillin will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.nefazodonenefazodone will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.nelfinavirnelfinavir will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.nevirapinenevirapine will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.oxcarbazepineoxcarbazepine will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.pentobarbitalpentobarbital will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.phenobarbitalphenobarbital will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.phenytoinphenytoin will decrease the level or effect of estrogens esterified by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. If the estrogen is being used for contraception then loss of contraception may occur. posaconazoleposaconazole will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.primidoneprimidone will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.quinidinequinidine will increase the level or effect of estrogens esterified by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely.quinupristin/dalfopristinquinupristin/dalfopristin will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ribociclibribociclib will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.rifabutinrifabutin will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.rifampinrifampin will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.rifapentinerifapentine will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ritonavirritonavir will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.secobarbitalsecobarbital will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.siponimodsiponimod and estrogens esterified both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.somapacitanestrogens esterified 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 WortSt John's Wort will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.stiripentolstiripentol, estrogens esterified. 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.tacrolimustacrolimus will increase the level or effect of estrogens esterified by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.tazemetostattazemetostat will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tecovirimattecovirimat will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.teriflunomideteriflunomide decreases levels of estrogens esterified by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.tolvaptantolvaptan will increase the level or effect of estrogens esterified by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.topiramatetopiramate will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Topiramate may compromise the efficacy of estrogens used for contraception or hormone replacement therapiesvalproic acidestrogens esterified will decrease the level or effect of valproic acid by increasing elimination. Modify Therapy/Monitor Closely. May lead to increased seizure frequencyverapamilverapamil will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.voriconazolevoriconazole will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.zafirlukastzafirlukast will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (34)acetazolamideacetazolamide will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.amitriptylineestrogens esterified, amitriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens may inhibit hepatic metabolism of tricyclic antidepressants. However, interactions are not common.amoxapineestrogens esterified, amoxapine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens may inhibit hepatic metabolism of tricyclic antidepressants. However, interactions are not common.anastrozoleanastrozole will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.boronboron increases levels of estrogens esterified by altering metabolism. Minor/Significance Unknown.clomipramineestrogens esterified, clomipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens may inhibit hepatic metabolism of tricyclic antidepressants. However, interactions are not common.cyanocobalaminestrogens esterified decreases levels of cyanocobalamin by altering metabolism. Minor/Significance Unknown.cyclophosphamidecyclophosphamide will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.desipramineestrogens esterified, desipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens may inhibit hepatic metabolism of tricyclic antidepressants. However, interactions are not common.dosulepinestrogens esterified, dosulepin. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.doxepinestrogens esterified, doxepin. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens may inhibit hepatic metabolism of tricyclic antidepressants. However, interactions are not common.folic acidestrogens esterified decreases levels of folic acid by altering metabolism. Minor/Significance Unknown.imipramineestrogens esterified, imipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens may inhibit hepatic metabolism of tricyclic antidepressants. However, interactions are not common.isoniazidisoniazid will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.L-methylfolateestrogens esterified decreases levels of L-methylfolate by altering metabolism. Minor/Significance Unknown.larotrectiniblarotrectinib will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.lofepramineestrogens esterified, lofepramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.magnesium chlorideestrogens esterified decreases levels of magnesium chloride by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.magnesium citrateestrogens esterified decreases levels of magnesium citrate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.magnesium hydroxideestrogens esterified decreases levels of magnesium hydroxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.magnesium oxideestrogens esterified decreases levels of magnesium oxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.magnesium sulfateestrogens esterified decreases levels of magnesium sulfate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.maprotilineestrogens esterified, maprotiline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.metyraponeestrogens esterified decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown. A subtherapeutic response to metyrapone can be seen in patients on estrogen therapy. It is generally advisable to discontinue estrogens prior to and during metyrapone administration.mycophenolatemycophenolate decreases effects of estrogens esterified by unknown mechanism. Minor/Significance Unknown. Clinical significance unclear.nortriptylineestrogens esterified, nortriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens may inhibit hepatic metabolism of tricyclic antidepressants. However, interactions are not common.phytoestrogensphytoestrogens decreases effects of estrogens esterified by pharmacodynamic antagonism. Minor/Significance Unknown.pleurisy rootpleurisy root decreases effects of estrogens esterified by unspecified interaction mechanism. Minor/Significance Unknown. Theoretical interaction.protriptylineestrogens esterified, protriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens may inhibit hepatic metabolism of tricyclic antidepressants. However, interactions are not common.pyridoxineestrogens esterified decreases levels of pyridoxine by altering metabolism. Minor/Significance Unknown.pyridoxine (Antidote)estrogens esterified decreases levels of pyridoxine (Antidote) by altering metabolism. Minor/Significance Unknown.rose hipsestrogens esterified decreases levels of rose hips by increasing elimination. Minor/Significance Unknown.trazodoneestrogens esterified, trazodone. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.trimipramineestrogens esterified, trimipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens may inhibit hepatic metabolism of tricyclic antidepressants. However, interactions are not common.abametapirSerious - Use Alternative (2)abametapir will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir. abametapir will increase the level or effect of estrogens esterified by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP1A2 substrates. If not feasible, avoid use of abametapir.acetazolamideMinor (1)acetazolamide will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.albiglutideMonitor Closely (1)estrogens esterified decreases effects of albiglutide by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may decrease hypoglycemic effects of antidiabetics by impairing glucose tolerance. Monitor for glycemic control in diabetic patients.amitriptylineMinor (1)estrogens esterified, amitriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens may inhibit hepatic metabolism of tricyclic antidepressants. However, interactions are not common.amobarbitalMonitor Closely (1)amobarbital will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.amoxapineMinor (1)estrogens esterified, amoxapine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens may inhibit hepatic metabolism of tricyclic antidepressants. However, interactions are not common.anastrozoleSerious - Use Alternative (1)estrogens esterified decreases effects of anastrozole by pharmacodynamic antagonism. Contraindicated. Estrogen may diminish the pharmacologic action of anastrozole. Coadministration not recommended.Minor (1)anastrozole will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.antithrombin alfaSerious - Use Alternative (1)estrogens esterified decreases effects of antithrombin alfa by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.apalutamideSerious - Use Alternative (1)apalutamide will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.aprepitantMonitor Closely (1)aprepitant will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Estrogens are CYP3A4 substrates, and the efficacy of estrogens when used for hormone replacement may be reduced.artemether/lumefantrineMonitor Closely (1)artemether/lumefantrine will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.atazanavirMonitor Closely (1)atazanavir, estrogens esterified. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Atazanavir may increase or decrease levels of estrogens esterified. Use alternatives if available.belzutifanMonitor Closely (1)belzutifan will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If unable to avoid coadministration of belzutifan with sensitive CYP3A4 substrates, consider increasing the sensitive CYP3A4 substrate dose in accordance with its prescribing information. boronMinor (1)boron increases