toremifene (Rx)

Brand and Other Names:Fareston

Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

tablet

  • 60mg

Breast Cancer

60 mg PO qDay until disease progresses

Monitor patients on warfarin for increased PT

Desmoid Tumors (Orphan)

Indicated for treatment of desmoid tumors

Orphan indication sponsor

  • Orion Corporation; PO Box 65; 02101 Espoo; FINLAND

Other Indications & Uses

Estrogen-receptor positive or unknown metastatic breast cancer in postmenopausal women

Not recommended

Next:

Interactions

Interaction Checker

and toremifene

No Results

     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

            All Interactions Sort By:
             activity indicator 

            Contraindicated (8)

            • dronedarone

              dronedarone and toremifene both increase QTc interval. Contraindicated. Concurrent use of dronedarone with other agents that prolong QTc interval is contraindicated.

            • goserelin

              goserelin increases toxicity of toremifene by QTc interval. Contraindicated. Increases risk of torsades de pointes.

            • lefamulin

              lefamulin will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lefamulin is contraindicated with CYP3A substrates know to prolong the QT interval.

            • leuprolide

              leuprolide increases toxicity of toremifene by QTc interval. Contraindicated. Increases risk of torsades de pointes.

            • nilotinib

              nilotinib and toremifene both increase QTc interval. Contraindicated. Avoid concurrent use of nilotinib with other QTc prolonging agents.

            • pimozide

              pimozide and toremifene both increase QTc interval. Contraindicated. Concurrent use of pimozide with other agents that prolong QTc interval is contraindicated.

            • thioridazine

              thioridazine and toremifene both increase QTc interval. Contraindicated. Concurrent use of thioridazine with other agents that prolong QTc interval is contraindicated.

            • ziprasidone

              ziprasidone and toremifene both increase QTc interval. Contraindicated. Concurrent use of ziprasidone with other agents that prolong QTc interval is contraindicated.

            Serious - Use Alternative (112)

            • abametapir

              abametapir will increase the level or effect of toremifene 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.

            • adagrasib

              adagrasib, toremifene. Either increases effects of the other by QTc interval. Avoid or Use Alternate Drug. Each drug prolongs the QTc interval, which may increased the risk of Torsade de pointes, other serious arryhthmias, and sudden death. If coadministration unavoidable, more frequent monitoring is recommended for such patients.

            • alfuzosin

              alfuzosin and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • amiodarone

              amiodarone and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • amisulpride

              amisulpride and toremifene both increase QTc interval. Avoid or Use Alternate Drug. ECG monitoring is recommended if coadministered.

            • amitriptyline

              amitriptyline and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • anagrelide

              anagrelide and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • apalutamide

              apalutamide will decrease the level or effect of toremifene 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.

            • apomorphine

              apomorphine and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • aripiprazole

              aripiprazole and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • arsenic trioxide

              arsenic trioxide and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • artemether

              artemether and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • asenapine

              asenapine and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • asenapine transdermal

              asenapine transdermal and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • atomoxetine

              atomoxetine and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • azithromycin

              azithromycin increases levels of toremifene by decreasing metabolism. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • buprenorphine

              buprenorphine and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • buprenorphine buccal

              buprenorphine buccal and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • buprenorphine subdermal implant

              buprenorphine subdermal implant and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • buprenorphine transdermal

              buprenorphine transdermal and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • buprenorphine, long-acting injection

              buprenorphine, long-acting injection and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • ceritinib

              ceritinib and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

              ceritinib will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • chloramphenicol

              chloramphenicol will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • ciprofloxacin

              ciprofloxacin and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • clarithromycin

              clarithromycin increases levels of toremifene by decreasing metabolism. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

              clarithromycin will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              clarithromycin and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • clomipramine

              clomipramine and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • clozapine

              clozapine and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • cobicistat

              cobicistat will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • conivaptan

              conivaptan will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • dasatinib

              dasatinib and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • degarelix

              degarelix and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • desflurane

              desflurane and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • desipramine

              desipramine and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • disopyramide

              disopyramide and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • dofetilide

              dofetilide and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • dolasetron

              dolasetron and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • donepezil

              donepezil and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • doxepin

              doxepin and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • efavirenz

              efavirenz and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • eliglustat

              eliglustat and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • encorafenib

              encorafenib and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Encorafenib is associated with dose-dependent QTc interval prolongation. Avoid with drugs known to prolong QT interval.

            • entrectinib

              toremifene and entrectinib both increase QTc interval. Avoid or Use Alternate Drug.

            • enzalutamide

              enzalutamide will decrease the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • eribulin

              eribulin and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Potential for enhanced QTc-prolonging effects; if concurrent use is necessary then ECG monitoring is recommended.

            • erythromycin base

              erythromycin base increases levels of toremifene by decreasing metabolism. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • erythromycin ethylsuccinate

              erythromycin ethylsuccinate increases levels of toremifene by decreasing metabolism. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • erythromycin lactobionate

              erythromycin lactobionate increases levels of toremifene by decreasing metabolism. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • erythromycin stearate

              erythromycin stearate increases levels of toremifene by decreasing metabolism. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • escitalopram

              escitalopram increases toxicity of toremifene by QTc interval. Avoid or Use Alternate Drug.

            • fexinidazole

              fexinidazole and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels and/or prolong QT interval.

              fexinidazole will increase the level or effect of toremifene 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.

            • fingolimod

              fingolimod and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • gemifloxacin

              gemifloxacin and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • gilteritinib

              gilteritinib and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • glasdegib

              toremifene and glasdegib both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, monitor for increased risk of QTc interval prolongation.

            • granisetron

              granisetron and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • haloperidol

              haloperidol and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • histrelin

              histrelin increases toxicity of toremifene by QTc interval. Avoid or Use Alternate Drug. Increases risk of torsades de pointes.

            • hydroxychloroquine sulfate

              hydroxychloroquine sulfate and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • hydroxyzine

              hydroxyzine and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • ibutilide

              ibutilide and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • idelalisib

              idelalisib will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates

            • imipramine

              imipramine and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • inotuzumab

              inotuzumab and toremifene both increase QTc interval. Avoid or Use Alternate Drug. If unable to avoid concomitant use, obtain ECGs and electrolytes before and after initiation of any drug known to prolong QTc, and periodically monitor as clinically indicated during treatment.

            • isoflurane

              isoflurane and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • itraconazole

              itraconazole and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • ivosidenib

              ivosidenib and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of QTc prolonging drugs with ivosidenib or replace with alternate therapies. If coadministration of a QTc prolonging drug is unavoidable, monitor for increased risk of QTc interval prolongation.

              ivosidenib will decrease the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.

            • ketoconazole

              ketoconazole increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • lapatinib

              lapatinib and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • levofloxacin

              levofloxacin and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • levoketoconazole

              levoketoconazole increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • lithium

              lithium and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • lonafarnib

              lonafarnib will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with sensitive CYP3A substrates. If coadministration unavoidable, monitor for adverse reactions and reduce CYP3A substrate dose in accordance with product labeling.

            • macimorelin

              macimorelin and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Macimorelin causes an increase of ~11 msec in the corrected QT interval. Avoid coadministration with drugs that prolong QT interval, which could increase risk for developing torsade de pointes-type ventricular tachycardia. Allow sufficient washout time of drugs that are known to prolong the QT interval before administering macimorelin.

            • mefloquine

              mefloquine and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • mifepristone

              mifepristone will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • mirtazapine

              mirtazapine and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • mobocertinib

              mobocertinib and toremifene both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, reduce mobocertinib dose and monitor QTc interval more frequently.

            • nortriptyline

              nortriptyline and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • ofloxacin

              ofloxacin and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • olanzapine

              olanzapine and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • ondansetron

              ondansetron and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

            • oxaliplatin

              oxaliplatin and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • palifermin

              palifermin increases toxicity of toremifene by Other (see comment). Avoid or Use Alternate Drug. Comment: Palifermin should not be administered within 24 hr before, during infusion of, or within 24 hr after administration of antineoplastic agents. Coadministration of palifermin within 24 hr of chemotherapy resulted in increased severity and duration of oral mucositis.

            • panobinostat

              toremifene and panobinostat both increase QTc interval. Avoid or Use Alternate Drug. Panobinostat is known to significantly prolong QT interval. Panobinostat prescribing information states use with drugs known to prolong QTc is not recommended.

            • pasireotide

              toremifene and pasireotide both increase QTc interval. Avoid or Use Alternate Drug.

            • pazopanib

              pazopanib and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • pimavanserin

              pimavanserin and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Coadministration may increase the risk of QT prolongation and cardiac arrhythmia.

            • pitolisant

              toremifene and pitolisant both increase QTc interval. Avoid or Use Alternate Drug.

            • primaquine

              primaquine and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • procainamide

              procainamide and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • propafenone

              propafenone and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • quinidine

              quinidine and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • ribociclib

              ribociclib and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

              ribociclib will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • sertraline

              sertraline and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • sevoflurane

              sevoflurane and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • siponimod

              siponimod and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • solifenacin

              solifenacin and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • sorafenib

              sorafenib and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • sotalol

              sotalol and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • sunitinib

              sunitinib and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • tacrolimus

              tacrolimus and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • tetrabenazine

              tetrabenazine and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • trazodone

              trazodone and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • triptorelin

              triptorelin increases toxicity of toremifene by QTc interval. Avoid or Use Alternate Drug. Increases risk of torsades de pointes.

            • tucatinib

              tucatinib will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.

            • umeclidinium bromide/vilanterol inhaled

              toremifene increases toxicity of umeclidinium bromide/vilanterol inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

            • vandetanib

              toremifene, vandetanib. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Avoid coadministration with drugs known to prolong QT interval; if a drug known to prolong QT interval must be used, more frequent ECG monitoring is recommended.

            • vemurafenib

              vemurafenib and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concomitant use of vemurafenib with drugs that prolong QT interval is not recommended.

            • venlafaxine

              venlafaxine and toremifene both increase QTc interval. Avoid or Use Alternate Drug. Concurrent use of toremifene with agents causing QT prolongation should be avoided. If concomitant use is required it's recommended that toremifene be interrupted. If interruption not possible, patients requiring therapy with a drug that prolongs QT should be closely monitored. ECGs should be obtained for high risk patients.

            • vilanterol/fluticasone furoate inhaled

              toremifene increases toxicity of vilanterol/fluticasone furoate inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

            • vorinostat

              vorinostat and toremifene both increase QTc interval. Avoid or Use Alternate Drug.

            • voxelotor

              voxelotor will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.

            Monitor Closely (87)

            • albuterol

              albuterol and toremifene both increase QTc interval. Use Caution/Monitor.

            • alfuzosin

              toremifene and alfuzosin both increase QTc interval. Use Caution/Monitor.

            • arformoterol

              arformoterol and toremifene both increase QTc interval. Use Caution/Monitor.

            • atazanavir

              atazanavir increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4.

            • bedaquiline

              toremifene and bedaquiline both increase QTc interval. Modify Therapy/Monitor Closely. ECG should be monitored closely

            • bosentan

              bosentan decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • carbamazepine

              carbamazepine decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • chloroquine

              chloroquine increases toxicity of toremifene by QTc interval. Use Caution/Monitor.

            • chlorothiazide

              chlorothiazide, toremifene. Other (see comment). Use Caution/Monitor. Comment: Thiazide diuretics decrease renal calcium excretion and may increase risk of hypercalcemia in patients taking toremifene.

            • chlorthalidone

              chlorthalidone, toremifene. Other (see comment). Use Caution/Monitor. Comment: Thiazide diuretics decrease renal calcium excretion and may increase risk of hypercalcemia in patients taking toremifene.

            • citalopram

              toremifene and citalopram both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended, along with drugs that may prolong the QT interval.

            • conivaptan

              conivaptan, toremifene. Other (see comment). Use Caution/Monitor. Comment: Upon completion or discontinuation of conivaptan, allow 7 days before initiating therapy with drugs that are CYP3A4 substrates. Monitor for any potential adverse effects.

            • crizotinib

              crizotinib and toremifene both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended, along with drugs that may prolong the QT interval.

            • crofelemer

              crofelemer increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.

            • dabrafenib

              dabrafenib will decrease the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

            • darunavir

              darunavir increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • deutetrabenazine

              toremifene and deutetrabenazine both increase QTc interval. Use Caution/Monitor. At the maximum recommended dose, deutetrabenazine does not prolong QT interval to a clinically relevant extent. Certain circumstances may increase risk of torsade de pointes and/or sudden death in association with drugs that prolong the QTc interval (eg, bradycardia, hypokalemia or hypomagnesemia, coadministration with other drugs that prolong QTc interval, presence of congenital QT prolongation).

            • dexamethasone

              dexamethasone decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • efavirenz

              efavirenz decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • elagolix

              elagolix decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

            • elvitegravir/cobicistat/emtricitabine/tenofovir DF

              elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

            • encorafenib

              encorafenib, toremifene. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.

            • eslicarbazepine acetate

              eslicarbazepine acetate will decrease the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • etravirine

              etravirine decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • ezogabine

              ezogabine, toremifene. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Slight and transient QT-prolongation observed with ezogabine, particularly when dose titrated to 1200 mg/day. QT interval should be monitored when ezogabine is prescribed with agents known to increase QT interval.

            • fedratinib

              fedratinib will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

            • fluoxetine

              toremifene and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.

            • fosamprenavir

              fosamprenavir increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • fosphenytoin

              fosphenytoin decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • fostemsavir

              toremifene and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.

            • gadobenate

              gadobenate and toremifene both increase QTc interval. Use Caution/Monitor.

            • gemtuzumab

              toremifene and gemtuzumab both increase QTc interval. Use Caution/Monitor.

            • hydrochlorothiazide

              hydrochlorothiazide, toremifene. Other (see comment). Use Caution/Monitor. Comment: Thiazide diuretics decrease renal calcium excretion and may increase risk of hypercalcemia in patients taking toremifene.

            • iloperidone

              iloperidone increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.

            • imatinib

              imatinib increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • indacaterol, inhaled

              indacaterol, inhaled, toremifene. QTc interval. Use Caution/Monitor. Drugs that are known to prolong the QTc interval may have an increased the risk of ventricular arrhythmias.

            • indinavir

              indinavir increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • isoniazid

              isoniazid increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • istradefylline

              istradefylline will increase the level or effect of toremifene 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.

            • itraconazole

              itraconazole increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • lenacapavir

              lenacapavir will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir 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.

            • lenvatinib

              toremifene and lenvatinib both increase QTc interval. Use Caution/Monitor. Lenvatinib prescribing information recommends monitoring ECG closely when coadministered with QT prolonging drugs.

            • lofexidine

              toremifene and lofexidine both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended.

            • lopinavir

              lopinavir increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • lorlatinib

              lorlatinib will decrease the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • methyclothiazide

              methyclothiazide, toremifene. Other (see comment). Use Caution/Monitor. Comment: Thiazide diuretics decrease renal calcium excretion and may increase risk of hypercalcemia in patients taking toremifene.

            • metolazone

              metolazone, toremifene. Other (see comment). Use Caution/Monitor. Comment: Thiazide diuretics decrease renal calcium excretion and may increase risk of hypercalcemia in patients taking toremifene.

            • mifepristone

              mifepristone, toremifene. QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.

            • mitotane

              mitotane decreases levels of toremifene 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.

            • nafcillin

              nafcillin decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • nefazodone

              nefazodone increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • nelfinavir

              nelfinavir increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • nevirapine

              nevirapine decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • nicardipine

              nicardipine increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • olodaterol inhaled

              toremifene and olodaterol inhaled both increase QTc interval. Use Caution/Monitor. Drugs that prolong the QTc interval and may potentiate the effects of beta2 agonists on the cardiovascular system; increased risk of ventricular arrhythmias

            • osilodrostat

              osilodrostat and toremifene both increase QTc interval. Use Caution/Monitor.

            • osimertinib

              osimertinib and toremifene both increase QTc interval. Use Caution/Monitor. Conduct periodic monitoring with ECGs and electrolytes in patients taking drugs known to prolong the QTc interval.

            • oxaliplatin

              oxaliplatin will increase the level or effect of toremifene by Other (see comment). Use Caution/Monitor. Monitor for ECG changes if therapy is initiated in patients with drugs known to prolong QT interval.

            • oxcarbazepine

              oxcarbazepine decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • ozanimod

              ozanimod and toremifene both increase QTc interval. Modify Therapy/Monitor Closely. The potential additive effects on heart rate, treatment with ozanimod should generally not be initiated in patients who are concurrently treated with QT prolonging drugs with known arrhythmogenic properties.

            • pentobarbital

              pentobarbital decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • phenobarbital

              phenobarbital decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • phenytoin

              phenytoin decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • posaconazole

              posaconazole increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • primidone

              primidone decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • quetiapine

              quetiapine, toremifene. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.

            • quinine

              toremifene and quinine both increase QTc interval. Use Caution/Monitor.

            • rifabutin

              rifabutin decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • rifampin

              rifampin decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • rifapentine

              rifapentine decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • rilpivirine

              rilpivirine increases toxicity of toremifene by QTc interval. Use Caution/Monitor. Rilpivirine should be used with caution when co-administered with a drug with a known risk of Torsade de Pointes.

            • ritonavir

              ritonavir increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • rucaparib

              rucaparib will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.

            • saquinavir

              saquinavir increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • selpercatinib

              selpercatinib increases toxicity of toremifene by QTc interval. Use Caution/Monitor.

            • siponimod

              siponimod and toremifene 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.

            • sodium sulfate/?magnesium sulfate/potassium chloride

              sodium sulfate/?magnesium sulfate/potassium chloride increases toxicity of toremifene by QTc interval. Use Caution/Monitor. Consider predose and post-colonoscopy ECGs in patients at increased risk of serious cardiac arrhythmias. .

            • sodium sulfate/potassium sulfate/magnesium sulfate

              sodium sulfate/potassium sulfate/magnesium sulfate increases toxicity of toremifene by QTc interval. Use Caution/Monitor. Consider predose and post-colonoscopy ECGs in patients at increased risk of serious cardiac arrhythmias. .

            • St John's Wort

              St John's Wort decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • stiripentol

              stiripentol, toremifene. 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.

            • sugammadex sodium

              toremifene decreases effects of sugammadex sodium by receptor binding competition. Modify Therapy/Monitor Closely. Toremifene binds to sugammadex and will likely displace some of vecuronium or rocuronium from sugammadex. The recovery to TOF ratio to 0.9 could therefore be delayed in patients who have received toremifene on the same day of surgery.

            • tazemetostat

              tazemetostat will decrease the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tecovirimat

              tecovirimat will decrease the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.

            • tipranavir

              tipranavir increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • triclabendazole

              triclabendazole and toremifene both increase QTc interval. Use Caution/Monitor.

            • voriconazole

              voriconazole increases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Metabolism of toremifene may be inhibited by drugs known to inhibit CYP3A4 hepatic enzymes.

            • warfarin

              toremifene increases effects of warfarin by unspecified interaction mechanism. Use Caution/Monitor.

            Minor (7)

            • acetazolamide

              acetazolamide will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • anastrozole

              anastrozole will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • cyclophosphamide

              cyclophosphamide will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • larotrectinib

              larotrectinib will increase the level or effect of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • maitake

              maitake increases effects of toremifene by pharmacodynamic synergism. Minor/Significance Unknown. Maitake mushroom has anti-tumor effects (animal/in vitro research).

            • phenytoin

              phenytoin decreases levels of toremifene by increasing metabolism. Minor/Significance Unknown.

            • taurine

              toremifene decreases levels of taurine by unspecified interaction mechanism. Minor/Significance Unknown.

            Previous
            Next:

            Adverse Effects

            >10%

            Hot flashes (35%)

            Sweating (20%)

            Nausea (14%)

            Vaginal discharge (13%)

            1-10%

            Cataracts (10%)

            Dizziness (9%)

            Edema (5%)

            Vomiting (4%)

            Dry eyes (4%)

            Hypercalcemia (3%)

            Thrombophlebitis (2%)

            Vaginal bleeding (2%)

            <1%

            Alopecia

            Angina

            Hepatitis

            Dermatitis

            Depression

            Corneal opacity

            Postmarketing

            Hepatototoxicity

            Risk of uterine malignancy

            Previous
            Next:

            Warnings

            Black Box Warnings

            Prolongs QTc interval in a dose- and concentration-related manner

            QT prolongation can result in Torsade de pointes, which may result in syncope, seizure, and/or death

            Should not be prescribed to patients with congenital/acquired QT prolongation, uncorrected hypokalemia or uncorrected hypomagnesemia

            Drugs known to prolong QT interval and strong CYP3A4 inhibitors should be avoided

            Contraindications

            Hypersensitivity

            Estrogen receptor-negative tumors

            Thromboembolic history

            Should not be prescribed to patients with congenital/acquired QT prolongation, uncorrected hypokalemia or uncorrected hypomagnesemia

            Cautions

            May increase risk of ovarian CA, osteosarcoma

            Risk of hypercalcemia & tumor flare

            Long-term treatment discouraged in preexisting endometrial hyperplasia

            Prolongs QTc interval; avoid in patients with congenital/acquired QT prolongation or uncorrected hypokalemia/hypomagnesemia

            Avoid concomitant use of drugs known to prolong QT interval

            Hepatotoxicity, both increases in serum concentration for grade 3 and 4 transaminitis; hyperbilirubinemia, including jaundice, hepatitis, and non-alcoholic fatty liver disease, have also been reported in clinical trials and postmarketing; liver function tests should be performed periodically

            Endometrial cancer, endometrial hypertrophy, hyperplasia, and uterine polyps reported; endometrial hyperplasia of uterus observed in animals treated with toremifene; long-term use has not been established in patients with pre-existing endometrial hyperplasia; all patients should have baseline and annual gynecological examinations; patients at high risk of endometrial cancer should be closely monitored

            Previous
            Next:

            Pregnancy & Lactation

            Pregnancy Category: D

            Lactation: Not known if excreted in breast milk, indicated in postmenopausal women

            Pregnancy Categories

            A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA: Information not available.

            Previous
            Next:

            Pharmacology

            Mechanism of Action

            Selective estrogen receptor modulator: nonsteroidal estrogen, agonist/antagonist, competes for estrogen binding sites on breast tumor cells

            Pharmacokinetics

            Half-Life: 5 days

            Peak Plasma Time: 3 hr

            Protein Bound: >99.5%

            Vd: 580 L

            Metabolism: Hepatic CYP3A4

            Metabolites: N-demethyltoremifene, (deamino-hydroxy) toremifene

            Clearance: 5 L/hr

            Excretion: Feces (primarily); urine (10%)

            Previous
            Next:

            Images

            BRAND FORM. UNIT PRICE PILL IMAGE
            Fareston oral
            -
            60 mg tablet

            Copyright © 2010 First DataBank, Inc.

            Previous
            Next:

            Patient Handout

            Patient Education
            toremifene oral

            TOREMIFENE - ORAL

            (tor-EM-eh-feen)

            COMMON BRAND NAME(S): Fareston

            WARNING: Toremifene has caused very serious (possibly fatal) heart rhythm problems (QT prolongation in the EKG, torsades de pointes). Get medical help right away if any of these rare but serious side effects occur: fast/irregular heartbeat, seizures, severe dizziness, or fainting. The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may affect the heart rhythm. Before using toremifene, tell your doctor or pharmacist of all the drugs you take (see also Drug Interaction section) and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using toremifene safely.

            USES: Toremifene is used in postmenopausal women to treat breast cancer. It is usually used to treat cancer that needs estrogen, a female hormone, in order to grow (estrogen-receptor positive). Toremifene is a nonsteroidal antiestrogen that blocks the effects of estrogen in the breast tissue, thereby slowing or stopping the growth of cancer.

            HOW TO USE: Take this medication by mouth with or without food as directed by your doctor, usually once daily. The dosage is based on your medical condition and response to treatment.Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.Avoid eating grapefruit or drinking grapefruit juice while using this medication unless your doctor or pharmacist says you may do so safely. Grapefruit can increase the chance of side effects with this medicine. Ask your doctor or pharmacist for more details.Since this drug can be absorbed through the skin and lungs, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets.Tell your doctor right away if your condition worsens (such as you get new breast lumps).

            SIDE EFFECTS: See also Warning section.Hot flashes, sweating, nausea, vomiting, dry eyes, or dizziness may occur. If any of these side effects last or get worse, tell your doctor promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: bone/joint/muscle pain or swelling, constipation, mental/mood changes (such as depression), trouble walking/clumsiness, swelling ankles/feet, unusual tiredness, vision changes (such as blurred vision, eye pain), easy bleeding/bruising, signs of infection (such as sore throat that doesn't go away, fever, chills), symptoms of liver disease (such as nausea/vomiting that doesn't stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine).Toremifene may increase your risk of uterine cancer. Tell your doctor right away if you develop changes in menstrual period, unusual vaginal bleeding/discharge or pain/pressure below your "belly button" (navel).Toremifene has rarely caused very serious (possibly fatal) blood clots in the lungs/legs, brain (stroke), and heart (heart attack). Get medical help right away if you develop pain/swelling in the groin/calf, pain in the chest/jaw/left arm, confusion, fainting, severe sudden headache, trouble speaking, sudden vision changes, shortness of breath, or weakness on one side of the body.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

            PRECAUTIONS: See also Warning section.Before taking toremifene, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: bone cancer (metastases), blood disorders (such as anemia, low platelets), diabetes, history of stroke or other blood clots (such as in the legs, lungs), heart disease (such as heart attack, irregular heartbeat), high blood pressure, liver disease, long periods of sitting or lying down (for example, due to immobility such as being bedridden), uterus problems such as endometrial hyperplasia.This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).Notify your doctor beforehand if you will be having surgery or will be confined to a chair/bed for a long time (such as on a long plane flight).During pregnancy, toremifene should be used only when clearly needed. It may harm an unborn baby. If you become pregnant or think you may be pregnant, inform your doctor right away. Women of childbearing age should use reliable forms of non-hormonal birth control (such as condoms, diaphragm with spermicide) while using this medication. Discuss the use of birth control, the risks and benefits of this medication, and any other concerns about using this medication with your doctor.It is unknown if this medication passes into breast milk. Because of the possible risk to the infant, breast-feeding while using this drug is not recommended. Consult your doctor before breast-feeding.

            DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug include: "blood thinners" (such as warfarin), estrogens, tibolone, drugs affecting liver enzymes that remove toremifene from your body (including certain anti-seizure medications such as carbamazepine/clonazepam/phenobarbital/phenytoin, rifampin).Many drugs besides toremifene may affect the heart rhythm (QT prolongation), including amiodarone, granisetron, pimozide, procainamide, quinidine, sotalol, and macrolide antibiotics (such as erythromycin), among others.

            OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.

            NOTES: Do not share this medication with others.Lab and/or medical tests (such as complete blood count, calcium levels, liver tests, pelvic exam) should be done before you start taking this medication and while you are taking it. Keep all medical and lab appointments. Consult your doctor for more details.

            MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

            STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

            Information last revised May 2023. Copyright(c) 2023 First Databank, Inc.

            IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.

            Previous
            Next:

            Formulary

            FormularyPatient Discounts

            Adding plans allows you to compare formulary status to other drugs in the same class.

            To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

            Adding plans allows you to:

            • View the formulary and any restrictions for each plan.
            • Manage and view all your plans together – even plans in different states.
            • Compare formulary status to other drugs in the same class.
            • Access your plan list on any device – mobile or desktop.

            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
            Additional Offers
            Email to Patient

            From:

            To:

            The recipient will receive more details and instructions to access this offer.

            By clicking send, you acknowledge that you have permission to email the recipient with this information.

            Email Forms to Patient

            From:

            To:

            The recipient will receive more details and instructions to access this offer.

            By clicking send, you acknowledge that you have permission to email the recipient with this information.

            Previous
            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.