recommended.mifepristone decreases effects of ethinylestradiol by pharmacodynamic antagonism. Use Caution/Monitor. Backup contraceptive method recommended.minocyclineminocycline will decrease the level or effect of ethinylestradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.nizatidinenizatidine will decrease the level or effect of ferrous fumarate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.mitotanemitotane decreases levels of ethinylestradiol 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.moxifloxacinmoxifloxacin will decrease the level or effect of ethinylestradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.nafcillinnafcillin will decrease the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.neomycin POneomycin PO will decrease the level or effect of ethinylestradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.nicardipineethinylestradiol will increase the level or effect of nicardipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.nilotinibethinylestradiol will increase the level or effect of nilotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.nirmatrelvirnirmatrelvir will decrease the level or effect of ethinylestradiol by increasing metabolism. Modify Therapy/Monitor Closely. Consider using additional nonhormonal contraceptive method for remainder of cycle. Mechanism unknown, but possibly by ritonavir CYP2C9 or CYP1A2 induction.nirmatrelvir/ritonavirnirmatrelvir/ritonavir will decrease the level or effect of ethinylestradiol by increasing metabolism. Modify Therapy/Monitor Closely. Consider using additional nonhormonal contraceptive method for remainder of cycle. Mechanism unknown, but possibly by ritonavir CYP2C9 or CYP1A2 induction.nitrofurantoinnitrofurantoin will decrease the level or effect of ethinylestradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.ofloxacinofloxacin will decrease the level or effect of ethinylestradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.olanzapineethinylestradiol will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.oteseconazoleoteseconazole will increase the level or effect of ethinylestradiol by Other (see comment). Modify Therapy/Monitor Closely. Otesezonale, a BCRP inhibitor, may increase the effects and risk of toxicities of BCRP substrates. Use lowest starting dose of BCRP substrate, or consider reducing BCRP substrate dose.paromomycinparomomycin will decrease the level or effect of ethinylestradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.penicillin G aqueouspenicillin G aqueous decreases levels of ethinylestradiol by increasing metabolism. Use Caution/Monitor. Risk of oral contraceptive failure.penicillin VKpenicillin VK will decrease the level or effect of ethinylestradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.pioglitazonepioglitazone decreases levels of ethinylestradiol by unknown mechanism. Use Caution/Monitor.posaconazoleposaconazole will increase the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.quinupristin/dalfopristinquinupristin/dalfopristin will increase the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ramelteonethinylestradiol will increase the level or effect of ramelteon by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.rasagilineethinylestradiol will increase the level or effect of rasagiline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Recommended dose of rasagiline is 0.5mg daily in combination with CYP1A2 inhibitors.ribociclibribociclib will increase the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.romidepsinromidepsin decreases effects of ethinylestradiol by receptor binding competition. Use Caution/Monitor.ropiniroleethinylestradiol will increase the level or effect of ropinirole by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.ethinylestradiol increases levels of ropinirole by unspecified interaction mechanism. Use Caution/Monitor.rucaparibrucaparib will increase the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.rucaparib will increase the level or effect of norethindrone acetate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.omadacyclineferrous fumarate will decrease the level or effect of omadacycline by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Multivalent cation-containing products may impair absorption of tetracyclines, which may decrease its efficacy. Separate dosing of tetracyclines from these products.rufinamiderufinamide decreases effects of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Rufinamide is a weak inducer of the CYP 3A4 enzyme and can decrease exposure of drugs that are substrates of CYP3A4. .omeprazoleomeprazole will decrease the level or effect of ferrous fumarate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.pancrelipasepancrelipase decreases levels of ferrous fumarate by enhancing GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Levels of iron salts may decrease with concomitant administration of digestive enzymes.pantoprazolepantoprazole will decrease the level or effect of ferrous fumarate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.penicillamineferrous fumarate decreases levels of penicillamine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Interaction only with oral iron administration.rabeprazolerabeprazole will decrease the level or effect of ferrous fumarate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.rufinamiderufinamide decreases effects of norethindrone acetate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Rufinamide is a weak inducer of the CYP 3A4 enzyme and can decrease exposure of drugs that are substrates of CYP3A4. .sarecyclineferrous fumarate will decrease the level or effect of sarecycline by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Multivalent cation-containing products may impair absorption of tetracyclines, which may decrease its efficacy. Separate dosing of tetracyclines from these products.selegilineethinylestradiol increases levels of selegiline by Other (see comment). Use Caution/Monitor. Comment: Oral contraceptives inhibit the N demethylatin of selegiline.selegiline transdermalethinylestradiol increases levels of selegiline transdermal by Other (see comment). Use Caution/Monitor. Comment: Oral contraceptives inhibit the N demethylatin of selegiline.siltuximabsiltuximab, ethinylestradiol. Other (see comment). Use Caution/Monitor. Comment: CYP450 activity in the liver is down regulated by infection and inflammation stimuli including cytokines (eg, IL-6); inhibition of IL-6 by siltuximab may restore CYP450 enzymatic activity; caution if coadministered with CYP substrates that have a narrow therapeutic index.siltuximab, norethindrone acetate. Other (see comment). Use Caution/Monitor. Comment: CYP450 activity in the liver is down regulated by infection and inflammation stimuli including cytokines (eg, IL-6); inhibition of IL-6 by siltuximab may restore CYP450 enzymatic activity; caution if coadministered with CYP substrates that have a narrow therapeutic index.sodium bicarbonatesodium bicarbonate will decrease the level or effect of ferrous fumarate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.somapacitanethinylestradiol will decrease the level or effect of somapacitan by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. Oral estrogens may reduce serum insulin-like growth factor I (IGF-1) response to growth hormone (GH) analogs. Higher GH dose may be requiredsodium citrate/citric acidsodium citrate/citric acid will decrease the level or effect of ferrous fumarate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.sodium picosulfate/magnesium oxide/anhydrous citric acidsodium picosulfate/magnesium oxide/anhydrous citric acid decreases levels of ferrous fumarate by cation binding in GI tract. Use Caution/Monitor. Take at least 2 hours before and not less than 6 hours after administration of sodium picosulfate, magnesium oxide and anhydrous citric acid to avoid magnesium chelation.sodium sulfate/?magnesium sulfate/potassium chloridesodium sulfate/?magnesium sulfate/potassium chloride decreases levels of ferrous fumarate by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Administer iron products at least 2 hr before and no less than 6 hr after each dose to avoid chelation with magnesium. .sodium sulfate/potassium sulfate/magnesium sulfatesodium sulfate/potassium sulfate/magnesium sulfate decreases levels of ferrous fumarate by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Administer iron products at least 2 hr before and no less than 6 hr after each dose to avoid chelation with magnesium. .sodium zirconium cyclosilicatesodium zirconium cyclosilicate will decrease the level or effect of ferrous fumarate by increasing gastric pH. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Check specific recommendations for drugs that exhibit pH-dependent solubility that may affect their systemic exposure and efficacy. In general, administer drugs at least 2 hr before or after sodium zirconium cyclosilicate.somatrogonethinylestradiol will decrease the level or effect of somatrogon by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. Oral estrogens may reduce serum insulin-like growth factor I (IGF-1) response to growth hormone (GH) analogs. Higher GH dose may be requiredsomatropinethinylestradiol will decrease the level or effect of somatropin by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. Oral estrogens may reduce serum insulin-like growth factor I (IGF-1) response to growth hormone (GH) analogs. Higher GH dose may be requiredstiripentolstiripentol, norethindrone acetate. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.stiripentol, ethinylestradiol. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.sulfadiazinesulfadiazine will decrease the level or effect of ethinylestradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.tazemetostattazemetostat will decrease the level or effect of norethindrone acetate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.sulfamethoxazolesulfamethoxazole will decrease the level or effect of ethinylestradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.sulfisoxazolesulfisoxazole will decrease the level or effect of ethinylestradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.tacrolimusethinylestradiol will increase the level or effect of tacrolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tazemetostattazemetostat will decrease the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ethinylestradiol will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tecovirimattecovirimat will decrease the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.tecovirimat will decrease the level or effect of norethindrone acetate 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 increases levels of ethinylestradiol by unknown mechanism. Use Caution/Monitor.thyroid desiccatedferrous fumarate decreases levels of thyroid desiccated by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.Minor (42)acetazolamideacetazolamide will increase the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.acetohydroxamic acidacetohydroxamic acid decreases levels of ferrous fumarate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.amitriptylineethinylestradiol, amitriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.amoxapineethinylestradiol, amoxapine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.anastrozoleanastrozole will increase the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.antipyrineethinylestradiol will increase the level or effect of antipyrine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.asenapineethinylestradiol will increase the level or effect of asenapine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.calcium acetatecalcium acetate decreases levels of ferrous fumarate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.ferrous fumarate increases levels of calcium acetate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.calcium carbonatecalcium carbonate decreases levels of ferrous fumarate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.ferrous fumarate increases levels of calcium carbonate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.calcium chloridecalcium chloride decreases levels of ferrous fumarate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.ferrous fumarate increases levels of calcium chloride by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.calcium citratecalcium citrate decreases levels of ferrous fumarate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.ferrous fumarate increases levels of calcium citrate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.calcium gluconatecalcium gluconate decreases levels of ferrous fumarate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.ferrous fumarate increases levels of