Dosing & Uses
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
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

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.
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
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
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.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%)
Images
BRAND | FORM. | UNIT PRICE | PILL IMAGE |
---|---|---|---|
Fareston oral - | 60 mg tablet | ![]() |
Copyright © 2010 First DataBank, Inc.
Patient Handout
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.
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