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Letrozole interactions

Full monograph for LetrozoleCheck it against another medicine

Medicines

335 documented

Medicines documented to interact with Letrozole, worst severity first.
MedicineSeverityMechanismEffectSources
Citalopram HydrobromideMajorMetabolismCoadministration with CYP450 2C19 inhibitors may increase the plasma concentrations of citalopram, which is partially metabolized by the isoenzyme. Cases of QT…9 sources — open the full entry
Drospirenone + EstetrolMajorsource also lists ModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
ThalidomideMajorSynergyCoadministration of thalidomide with glucocorticoids and/or antineoplastic agents in the treatment of malignancy may potentiate the risk of thromboembolism…20 sources — open the full entry
AbametapirModerateMetabolismBased on in vitro inhibition data, a single topical application of abametapir lotion may increase plasma concentrations of drugs that are substrates of CYP450…1 sources — open the full entry
ApalutamideModerateAbsorption · MetabolismCoadministration with apalutamide may decrease the plasma concentrations and therapeutic effects of drugs that are substrates of CYP450 3A4, 2C9, 2C19, breast…5 sources — open the full entry
AprepitantModerateMetabolismCoadministration with aprepitant or its prodrug, fosaprepitant, may increase the plasma concentrations of drugs that are primarily metabolized by CYP450 3A4…2 sources — open the full entry
AsciminibModerateMetabolismCoadministration with asciminib may increase the plasma concentrations of drugs that are primarily metabolized by the CYP450 3A4 isoenzyme. The mechanism is…1 sources — open the full entry
Bosentan MonohydrateModerateMetabolismCoadministration with bosentan may decrease the plasma concentrations of drugs that are substrates of the CYP450 2C9 and/or 3A4 isoenzymes. The mechanism is…5 sources — open the full entry
BrigatinibModerateMetabolismCoadministration with brigatinib may decrease the plasma concentrations of drugs that are substrates of the CYP450 3A4 isoenzyme. Brigatinib has been shown in…6 sources — open the full entry
CenobamateModerateMetabolismCoadministration with cenobamate may decrease the plasma concentrations and pharmacologic effects of CYP450 3A4 substrates. The proposed mechanism is…1 sources — open the full entry
CeritinibModerateMetabolismCoadministration with ceritinib may increase the plasma concentration and the risk of adverse effects of drugs that are substrates of CYP450 2A6 and/or 2E1…8 sources — open the full entry
CilostazolModerateMetabolismCoadministration with inhibitors of CYP450 3A4 and/or 2C19 may increase the plasma concentrations of cilostazol and or its pharmacologically active…11 sources — open the full entry
ClobazamModerateMetabolismCoadministration of clobazam with inhibitors of CYP450 2C19 may significantly increase the plasma concentrations of its active metabolite, N-desmethylclobazam…7 sources — open the full entry
Clopidogrel + AspirinModerateMetabolism · UnknownCoadministration with inhibitors of CYP450 2C19 may reduce the efficacy of clopidogrel, whose antiplatelet effect is dependent in part on bioactivation by the…2 documented mechanisms21 sources — open the full entry
Clopidogrel BisulphateModerateMetabolismCoadministration with inhibitors of CYP450 2C19 may reduce the efficacy of clopidogrel, whose antiplatelet effect is dependent in part on bioactivation by the…21 sources — open the full entry
Conjugated EstrogenCreamTabletModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
Conjugated Estrogen + BazedoxifeneModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
Cyproterone Acetate + Ethinyl EstradiolModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
DasatinibModerateMetabolismCoadministration with dasatinib may increase the plasma concentrations of drugs that are substrates of CYP450 3A4. The mechanism is decreased clearance due to…8 sources — open the full entry
DeferasiroxModerateMetabolismCoadministration with deferasirox may decrease the plasma concentrations of drugs that are substrates of the CYP450 3A4 isoenzyme. The mechanism may involve…3 sources — open the full entry
Dienogest + Estradiol ValerateModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
Drospirenone + EstradiolModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
Drospirenone + Ethinyl Estradiol0.02 mg0.03 mgModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
Drospirenone + Ethinyl Estradiol + LevomefolateModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
EfavirenzModerateMetabolismCoadministration with efavirenz may decrease the plasma concentrations of drugs that are substrates of the CYP450 3A4 isoenzyme. The mechanism is accelerated…2 sources — open the full entry
EnzalutamideModerateMetabolismCoadministration with enzalutamide may decrease the plasma concentrations of drugs that are substrates of CYP450 3A4, 2C9, 2C19, and/or P-glycoprotein (P-gp)…4 sources — open the full entry
Escitalopram OxalateModerateMetabolismCoadministration with inhibitors of CYP450 2C19 may increase the plasma concentrations of escitalopram, which is primarily metabolized by the isoenzyme. High…18 sources — open the full entry
Estradiolbasevaginal creamModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
Estradiol + DydrogesteroneModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
Estradiol Hemihydrate + Progesterone MicronizedModerateAntagonism · UnknownTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…2 documented mechanisms3 sources — open the full entry
Estradiol ValerateModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
Ethinyl Estradiol + Desogestrel0.02 mg0.03 mgModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
Ethinyl Estradiol + GestodeneModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
Ethinyl Estradiol + Levonorgestrel + Ferrous FumarateModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
Ethinyl Estradiol + Lynestrenol0.0375 mg0.05 mgModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
FenofibrateModerateMetabolismCoadministration with fenofibrate may increase the plasma concentrations and risk of adverse effects of drugs that are substrates of CYP450 2C19, 2A6, and 2C9…37 sources — open the full entry
FlibanserinModerateMetabolismCoadministration with inhibitors of CYP450 2C19 may increase the plasma concentrations of flibanserin, which is partially metabolized by the isoenzyme. High…6 sources — open the full entry
Hydroxyprogesterone CaproateModerateMetabolismCoadministration with hydroxyprogesterone may decrease the plasma concentrations of drugs that are metabolized by CYP450 1A2, 2A6, and/or 2B6.1 sources — open the full entry
Lamivudine + Zidovudine + NevirapineModerateMetabolismCoadministration with nevirapine may decrease the plasma concentrations and therapeutic efficacy of drugs that are substrates of CYP450 3A4. The proposed…4 sources — open the full entry
LapatinibModerateMetabolismCoadministration with lapatinib may increase the plasma concentrations of drugs that are substrates of the CYP450 2C8 isoenzyme, CYP450 3A4 isoenzyme, and/or…6 sources — open the full entry
LarotrectinibModerateMetabolismCoadministration with larotrectinib may increase the plasma concentrations of drugs that are substrates of the CYP450 3A4 isoenzyme.4 sources — open the full entry
Lefamulin AcetateModerateMetabolismWhen administered orally, lefamulin may increase the plasma concentrations of drugs that are primarily metabolized by CYP450 3A4. Based on interaction with…6 sources — open the full entry
LorlatinibModerateMetabolismCoadministration with lorlatinib may decrease the plasma concentrations of drugs that are substrates of the CYP450 3A4 isoenzyme. The proposed mechanism is…3 sources — open the full entry
MavacamtenModerateMetabolismCoadministration with mavacamten may decrease the plasma concentrations of drugs that are primarily metabolized by CYP450 3A4, 2C9, and/or 2C19. The proposed…1 sources — open the full entry
Medroxyprogesterone AcetateInjectionTabletModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
MifepristoneModerateMetabolismBased on in vitro inhibition data, coadministration with mifepristone may increase the plasma concentrations of drugs that are substrates of the CYP450 3A4…10 sources — open the full entry
Mifepristone + MisoprostolModerateMetabolismBased on in vitro inhibition data, coadministration with mifepristone may increase the plasma concentrations of drugs that are substrates of the CYP450 3A4…10 sources — open the full entry
NilotinibModerateMetabolismBased on in vitro inhibition data, coadministration with nilotinib may increase the plasma concentrations of drugs that are substrates of the P-glycoprotein…6 sources — open the full entry
Norgestrel + Ethinyl Estradiol + Ferrous FumarateModerateAntagonismTheoretically, estrogen-containing drugs may negate the pharmacologic effects of aromatase inhibitors in the treatment of hormone-dependent breast cancer…3 sources — open the full entry
OxcarbazepineModerateMetabolismCoadministration with oxcarbazepine may decrease the plasma concentrations of drugs that are substrates of the CYP450 3A4 isoenzyme. The mechanism is…9 sources — open the full entry

Conditions

Conditions in which Letrozole needs care, as documented in this source.