Dosing & Uses
Dosage Forms & Strengths
tablet, extended-release
- 600mg
HIV Infection
Indicated in combination with other antiretroviral (ATV) drugs for treatment of HIV-1 infection in heavily treatment-experienced adults with multidrug-resistant HIV-1 infection failing their current antiretroviral treatment (ART) regimen owing to resistance, intolerance, or safety considerations
600 mg PO BID
Dosage Modifications
Any severity of hepatic or renal impairment, including hemodialysis: No dosage adjustment required
Safety and efficacy not established
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (23)
- amobarbital
amobarbital will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- apalutamide
apalutamide will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- bosentan
bosentan will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- butabarbital
butabarbital will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- butalbital
butalbital will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- carbamazepine
carbamazepine will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- dabrafenib
dabrafenib will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- efavirenz
efavirenz will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- enzalutamide
enzalutamide will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- fosphenytoin
fosphenytoin will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- ivosidenib
ivosidenib will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- lorlatinib
lorlatinib will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- lumacaftor/ivacaftor
lumacaftor/ivacaftor will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- mitotane
mitotane will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- nafcillin
nafcillin will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- pentobarbital
pentobarbital will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- phenobarbital
phenobarbital will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- phenytoin
phenytoin will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- primidone
primidone will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- rifampin
rifampin will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- rifapentine
rifapentine will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- secobarbital
secobarbital will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
- St John's Wort
St John's Wort will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.
Serious - Use Alternative (21)
- adagrasib
adagrasib, fostemsavir. 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.
- amisulpride
amisulpride and fostemsavir both increase QTc interval. Avoid or Use Alternate Drug. QTc prolongation reported with higher than recommended doses of fostemsavir.
- artemether
artemether and fostemsavir both increase QTc interval. Avoid or Use Alternate Drug.
- atogepant
fostemsavir will increase the level or effect of atogepant by Other (see comment). Avoid or Use Alternate Drug. If unavoidable, recommended dosage of atogepant (an OATP1B1 substrate) with concomitant use of OATP inhibitors is 10 mg or 30 mg qDay.
- belzutifan
belzutifan will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fostemsavir is a prodrug and is contraindicated with strong CYP3A4 inducers. Belzutifan (a moderate CYP3A4 inducer) may decrease conversion of fostemsavir to active form.
- betibeglogene autotemcel
fostemsavir, betibeglogene autotemcel. Other (see comment). Avoid or Use Alternate Drug. Comment: Do not take antiretroviral medications for at least 1 month before mobilization or expected duration for elimination of the medications, and until all cycles of apheresis are completed. Antiretroviral medications may interfere with manufacturing of apheresed cells.
- buprenorphine
buprenorphine and fostemsavir both increase QTc interval. Avoid or Use Alternate Drug.
- buprenorphine buccal
buprenorphine buccal and fostemsavir both increase QTc interval. Avoid or Use Alternate Drug.
- buprenorphine subdermal implant
buprenorphine subdermal implant and fostemsavir both increase QTc interval. Avoid or Use Alternate Drug.
- buprenorphine transdermal
buprenorphine transdermal and fostemsavir both increase QTc interval. Avoid or Use Alternate Drug.
- buprenorphine, long-acting injection
buprenorphine, long-acting injection and fostemsavir both increase QTc interval. Avoid or Use Alternate Drug.
- cabotegravir
fostemsavir, cabotegravir. Other (see comment). Avoid or Use Alternate Drug. Comment: Cabotegravir plus rilpivirine is a complete regimen. Coadministration with other antiretroviral medications for treating HIV-1 infection is not recommended.
- clarithromycin
clarithromycin and fostemsavir both increase QTc interval. Avoid or Use Alternate Drug.
- elbasvir/grazoprevir
fostemsavir will increase the level or effect of elbasvir/grazoprevir by Other (see comment). Avoid or Use Alternate Drug. Fostemsavir inhibits OATP1B1/3 transporter. Higher grazoprevir system exposure may increase risk of ALT elevations. Use an alternative HCV regimen if possible.
- elivaldogene autotemcel
elivaldogene autotemcel, fostemsavir. Either decreases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Patients should not take antiretroviral medications for at least 1 month before initiating medications for stem cell mobilization, for the duration of the medications? elimination, and until all cycles of apheresis are completed.
- fexinidazole
fexinidazole and fostemsavir both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels or prolong QT interval.
- mobocertinib
mobocertinib and fostemsavir both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, reduce mobocertinib dose and monitor QTc interval more frequently.
- rimegepant
fostemsavir will increase the level or effect of rimegepant by Other (see comment). Avoid or Use Alternate Drug. Fostemsavir inhibits BCRP transporters.
- sulbactam/durlobactam
fostemsavir will increase the level or effect of sulbactam/durlobactam by Other (see comment). Avoid or Use Alternate Drug. Sulbactam is predicted to have active secretion by OATP1 as a significant portion of total clearance; therefore, inhibition of OAT1 may increase sulbactam plasma concentrations
- voxilaprevir
fostemsavir will increase the level or effect of voxilaprevir by Other (see comment). Avoid or Use Alternate Drug. Fostemsavir inhibits OATP1B1/3 and BCRP transporters. Higher voxilaprevir system exposure may increase risk of ALT elevations. Use an alternative HCV regimen if possible.
- zavegepant intranasal
fostemsavir will increase the level or effect of zavegepant intranasal by Other (see comment). Avoid or Use Alternate Drug. OATP1B3 inhibitors may result in a significant increase in systemic exposure of zavegepant (an OATP1B3 substrate).
Monitor Closely (206)
- albuterol
albuterol and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- alfuzosin
alfuzosin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- alpelisib
fostemsavir will increase the level or effect of alpelisib by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- ambrisentan
fostemsavir will increase the level or effect of ambrisentan by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- amiodarone
amiodarone and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- amitriptyline
amitriptyline and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- anagrelide
anagrelide and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- apomorphine
apomorphine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- arformoterol
arformoterol and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- aripiprazole
aripiprazole and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- arsenic trioxide
arsenic trioxide and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- artemether/lumefantrine
artemether/lumefantrine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- asenapine
asenapine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- asenapine transdermal
asenapine transdermal and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- atomoxetine
atomoxetine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- atorvastatin
fostemsavir will increase the level or effect of atorvastatin by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 and BCRP transporters. If possible, avoid coadministration or modify dose of OATP1B1/3 or BCRP substrates coadministered with fostemsavir. Use lowest possible starting dose for statins and monitor for associated adverse events.
- azithromycin
azithromycin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- bedaquiline
bedaquiline and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- berotralstat
fostemsavir increases levels of berotralstat by Other (see comment). Modify Therapy/Monitor Closely. Comment: Reduced dose of berotralstat (a BCRP substrate) to 110 mg/day when coadministered with BCRP inhibitors.
- bosentan
fostemsavir will increase the level or effect of bosentan by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- bosutinib
bosutinib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- capecitabine
capecitabine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- caspofungin
fostemsavir will increase the level or effect of caspofungin by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- ceritinib
ceritinib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- chloroquine
chloroquine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- chlorothiazide
fostemsavir will increase the level or effect of chlorothiazide by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- chlorpromazine
chlorpromazine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- cimetidine
fostemsavir will increase the level or effect of cimetidine by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- ciprofloxacin
ciprofloxacin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- clofazimine
clofazimine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- clozapine
clozapine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- crizotinib
crizotinib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- dabrafenib
dabrafenib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- dasatinib
dasatinib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- daunorubicin
fostemsavir will increase the level or effect of daunorubicin by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- daunorubicin liposomal
fostemsavir will increase the level or effect of daunorubicin liposomal by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- degarelix
degarelix and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- desflurane
desflurane and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- desipramine
desipramine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- deutetrabenazine
deutetrabenazine and fostemsavir 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).
- digoxin
fostemsavir will increase the level or effect of digoxin by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- dipyridamole
fostemsavir will increase the level or effect of dipyridamole by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- disopyramide
disopyramide and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- dofetilide
dofetilide and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- dolasetron
dolasetron and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- donepezil
donepezil and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- doxepin
doxepin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- doxorubicin
fostemsavir will increase the level or effect of doxorubicin by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- doxorubicin liposomal
fostemsavir will increase the level or effect of doxorubicin liposomal by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- dronedarone
dronedarone and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- droperidol
droperidol and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- efavirenz
efavirenz and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- elagolix
fostemsavir will increase the level or effect of elagolix by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- eliglustat
eliglustat and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- eluxadoline
fostemsavir will increase the level or effect of eluxadoline by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- enalapril
fostemsavir will increase the level or effect of enalapril by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- encorafenib
encorafenib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- entrectinib
entrectinib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- eribulin
eribulin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- erythromycin base
fostemsavir will increase the level or effect of erythromycin base by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
erythromycin base and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir. - erythromycin ethylsuccinate
fostemsavir will increase the level or effect of erythromycin ethylsuccinate by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
erythromycin ethylsuccinate and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir. - erythromycin lactobionate
fostemsavir will increase the level or effect of erythromycin lactobionate by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
erythromycin lactobionate and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir. - erythromycin stearate
fostemsavir will increase the level or effect of erythromycin stearate by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
erythromycin stearate and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir. - escitalopram
escitalopram and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- ethinylestradiol
fostemsavir will increase the level or effect of ethinylestradiol by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir. Do not ethinyl estradiol dose of exceed 30 mcg/day.
- ezetimibe
fostemsavir will increase the level or effect of ezetimibe by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- ezogabine
ezogabine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- fexofenadine
fostemsavir will increase the level or effect of fexofenadine by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- fingolimod
fingolimod and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- flecainide
flecainide and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- floxuridine
floxuridine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- fluconazole
fluconazole and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- fluoxetine
fluoxetine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- fluphenazine
fluphenazine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- fluvastatin
fostemsavir will increase the level or effect of fluvastatin by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 and BCRP transporters. If possible, avoid coadministration or modify dose of OATP1B1/3 or BCRP substrates coadministered with fostemsavir. Use lowest possible starting dose for statins and monitor for associated adverse events.
- formoterol
formoterol and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- foscarnet
foscarnet and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- gadobenate
gadobenate and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- gemifloxacin
gemifloxacin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- gemtuzumab
gemtuzumab and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- gilteritinib
gilteritinib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- glasdegib
glasdegib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- glecaprevir/pibrentasvir
fostemsavir will increase the level or effect of glecaprevir/pibrentasvir by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- glyburide
fostemsavir will increase the level or effect of glyburide by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 and BCRP transporters. If possible, avoid coadministration or modify dose of OATP1B1/3 or BCRP substrates coadministered with fostemsavir.
- goserelin
goserelin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- granisetron
granisetron and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- haloperidol
haloperidol and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- hydroxychloroquine sulfate
hydroxychloroquine sulfate and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- hydroxyzine
hydroxyzine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- ibutilide
ibutilide and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- iloperidone
iloperidone and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- imatinib
fostemsavir will increase the level or effect of imatinib by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 and BCRP transporters. If possible, avoid coadministration or modify dose of OATP1B1/3 or BCRP substrates coadministered with fostemsavir.
- indacaterol, inhaled
indacaterol, inhaled and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- inotuzumab
inotuzumab and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- irinotecan
fostemsavir will increase the level or effect of irinotecan by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- irinotecan liposomal
fostemsavir will increase the level or effect of irinotecan liposomal by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- isoflurane
isoflurane and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- itraconazole
itraconazole and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- ivosidenib
ivosidenib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- lapatinib
fostemsavir will increase the level or effect of lapatinib by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
lapatinib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir. - ledipasvir/sofosbuvir
fostemsavir will increase the level or effect of ledipasvir/sofosbuvir by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- lefamulin
lefamulin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- leflunomide
fostemsavir will increase the level or effect of leflunomide by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- lenacapavir
lenacapavir will increase the level or effect of fostemsavir 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
fostemsavir will increase the level or effect of lenvatinib by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
lenvatinib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir. - letermovir
fostemsavir will increase the level or effect of letermovir by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- leuprolide
leuprolide and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- levalbuterol
levalbuterol and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- levofloxacin
levofloxacin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- lithium
lithium and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- lofexidine
lofexidine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- loperamide
loperamide and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- lopinavir
lopinavir and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- lovastatin
fostemsavir will increase the level or effect of lovastatin by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- lumefantrine
lumefantrine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- macimorelin
macimorelin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- mefloquine
mefloquine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- methotrexate
fostemsavir will increase the level or effect of methotrexate by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 and BCRP transporters. If possible, avoid coadministration or modify dose of OATP1B1/3 or BCRP substrates coadministered with fostemsavir.
- midostaurin
midostaurin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- mifepristone
mifepristone and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- mirtazapine
mirtazapine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- mitoxantrone
fostemsavir will increase the level or effect of mitoxantrone by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- momelotinib
fostemsavir increases toxicity of momelotinib by Other (see comment). Use Caution/Monitor. Comment: OATP1B1/B3 inhibitor increases momelotinib (OATP1B1/B3 subtrate) plasma concentrations, which may increase the risk of adverse reactions with momelotinib.
- moxifloxacin
moxifloxacin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- nilotinib
nilotinib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- nitrofurantoin
fostemsavir will increase the level or effect of nitrofurantoin by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- nortriptyline
nortriptyline and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- ofloxacin
ofloxacin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- olanzapine
olanzapine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- olmesartan
fostemsavir will increase the level or effect of olmesartan by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- olodaterol inhaled
olodaterol inhaled and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC)
fostemsavir will increase the level or effect of ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- ondansetron
ondansetron and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- osilodrostat
osilodrostat and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- osimertinib
fostemsavir will increase the level or effect of osimertinib by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
osimertinib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir. - oxaliplatin
oxaliplatin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- oxytocin
oxytocin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- ozanimod
fostemsavir will increase the level or effect of ozanimod by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- paliperidone
paliperidone and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- panobinostat
panobinostat and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- pantoprazole
fostemsavir will increase the level or effect of pantoprazole by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- pasireotide
pasireotide and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- pazopanib
fostemsavir will increase the level or effect of pazopanib by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
pazopanib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir. - penicillin G aqueous
fostemsavir will increase the level or effect of penicillin G aqueous by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- pentamidine
pentamidine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- pimavanserin
pimavanserin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- pimozide
pimozide and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- pitavastatin
fostemsavir will increase the level or effect of pitavastatin by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 and BCRP transporters. If possible, avoid coadministration or modify dose of OATP1B1/3 or BCRP substrates coadministered with fostemsavir. Use lowest possible starting dose for statins and monitor for associated adverse events.
- pitolisant
pitolisant and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- pravastatin
fostemsavir will increase the level or effect of pravastatin by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir. Use lowest possible starting dose for statins and monitor for associated adverse events.
- primaquine
primaquine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- procainamide
procainamide and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- propafenone
propafenone and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- propofol
propofol and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- quetiapine
quetiapine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- quinidine
quinidine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- quinine
quinine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- quizartinib
quizartinib, fostemsavir. Either increases effects of the other by QTc interval. Modify Therapy/Monitor Closely. Monitor patients more frequently with ECG if coadministered with QT prolonging drugs.
- ranolazine
ranolazine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- repaglinide
fostemsavir will increase the level or effect of repaglinide by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- revefenacin
fostemsavir will increase the level or effect of revefenacin by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- ribociclib
ribociclib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- rilpivirine
rilpivirine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- riociguat
fostemsavir will increase the level or effect of riociguat by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- risperidone
risperidone and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- romidepsin
romidepsin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- rosuvastatin
fostemsavir will increase the level or effect of rosuvastatin by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 and BCRP transporters. If possible, avoid coadministration or modify dose of OATP1B1/3 or BCRP substrates coadministered with fostemsavir. Use lowest possible starting dose for statins and monitor for associated adverse events.
- salmeterol
salmeterol and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- saquinavir
saquinavir and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- segesterone/ethinyl estradiol
fostemsavir will increase the level or effect of segesterone/ethinyl estradiol by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir. Do not ethinyl estradiol dose of exceed 30 mcg/day.
- selexipag
fostemsavir will increase the level or effect of selexipag by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- selumetinib
fostemsavir will increase the level or effect of selumetinib by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- sertraline
sertraline and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- sevoflurane
sevoflurane and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- simvastatin
fostemsavir will increase the level or effect of simvastatin by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 and BCRP transporters. If possible, avoid coadministration or modify dose of OATP1B1/3 or BCRP substrates coadministered with fostemsavir. Use lowest possible starting dose for statins and monitor for associated adverse events.
- siponimod
siponimod and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- sofosbuvir
fostemsavir will increase the level or effect of sofosbuvir by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- solifenacin
solifenacin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- sorafenib
sorafenib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- sotalol
sotalol and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- sulfasalazine
fostemsavir will increase the level or effect of sulfasalazine by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- sunitinib
sunitinib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- tacrolimus
tacrolimus and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- talazoparib
fostemsavir will increase the level or effect of talazoparib by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- telavancin
telavancin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- telmisartan
fostemsavir will increase the level or effect of telmisartan by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- terbutaline
terbutaline and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- tetrabenazine
tetrabenazine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- thioridazine
thioridazine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- topotecan
fostemsavir will increase the level or effect of topotecan by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- toremifene
toremifene and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- trazodone
trazodone and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- triclabendazole
triclabendazole and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- triptorelin
triptorelin and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- troglitazone
fostemsavir will increase the level or effect of troglitazone by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- ublituximab
ublituximab decreases effects of fostemsavir by immunosuppressive effects; risk of infection. Modify Therapy/Monitor Closely.
- ubrogepant
fostemsavir will increase the level or effect of ubrogepant by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- valbenazine
valbenazine and fostemsavir both increase QTc interval. Use Caution/Monitor.
- valsartan
fostemsavir will increase the level or effect of valsartan by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits OATP1B1/3 transporter. If possible, avoid coadministration or modify dose of OATP1B1/3 substrates coadministered with fostemsavir.
- vandetanib
vandetanib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- vardenafil
vardenafil and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- velpatasvir
fostemsavir will increase the level or effect of velpatasvir by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
- vemurafenib
fostemsavir will increase the level or effect of vemurafenib by Other (see comment). Modify Therapy/Monitor Closely. Fostemsavir inhibits BCRP transporters. If possible, avoid coadministration or modify dose of BCRP substrate coadministered with fostemsavir.
vemurafenib and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir. - voriconazole
voriconazole and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
- vorinostat
vorinostat and fostemsavir both increase QTc interval. Use Caution/Monitor.
- ziprasidone
ziprasidone and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.
Minor (0)
Adverse Effects
>10%
Creatinine >1.8 x ULN or 1.5 x baseline (19%)
1-10%
Nausea (10%)
Direct bilirubin >ULN (7%)
Hemoglobin <9 g/dL (6%)
Cholesterol ≥300 mg/dL) (5%)
Lipase >3x ULN (5%)
Triglycerides >500 mg/dL (5%)
ALT >5x ULN (5%)
AST >5x ULN (4%)
Hyperglycemia >250 mg/dL (4%)
LDL cholesterol ≥190 mg/dL
Neutrophils ≤599 cells/mm3 (4%)
Diarrhea (4%)
Headache (4%)
Bilirubin ≥2.6x ULN (3%)
Urate >12 mg/dL (3%)
Abdominal pain (3%)
Dyspepsia (3%)
Fatigue (3%)
Rash (3%)
Sleep disturbance (3%)
Immune reconstitution inflammatory syndrome (2%)
Somnolence (2%)
Vomiting (2%)
Creatinine kinase ≥10x ULN (2%)
<2%
- Cardiac disorders: ECG QT prolonged (asymptomatic)
- Musculoskeletal disorders: Myalgia
- Nervous system disorders: Dizziness, dysgeusia, peripheral neuropathy
- Skin and subcutaneous tissue disorders: Pruritus
Warnings
Contraindications
Hypersensitivity to fostemsavir or any of its components
Coadministered strong CYP3A inducers (eg, enzalutamide, carbamazepine, phenytoin, rifampin, mitotane, St John’s wort), as significant decreases in temsavir (the active moiety of fostemsavir) plasma concentrations may occur, which may result in loss of virologic response
Cautions
Immune reconstitution syndrome reported with combination antiretroviral therapy; an inflammatory response to indolent or residual opportunistic infections (eg, Mycobacterium avium infection, cytomegalovirus, Pneumocystis jirovecii pneumonia, or tuberculosis) may occur, which may necessitate further evaluation and treatment; autoimmune disorders (eg, Grave disease, polymyositis, Guillain-Barré) also reported
Monitor liver enzymes in patients coinfected with hepatitis B or C virus; elevated hepatic transaminases observed in greater proportion of coinfected individuals; maintain/initiate effective hepatitis B therapy when initiating fostemsavir to avoid hepatitis B reactivation
Drug interaction overview
-
CYP3A4 inducers
- Contraindicated
- Temsavir (active moiety) is a CYP3A4 substrate
- Coadministration with strong CYP3A4 inducers significantly decreases temsavir plasma concentrations, which may lead to loss of virologic response and resistance
-
QT prolongation
- Caution with history of prolonged QT, torsade de Pointes, or cardiac disease prone to arrhythmias
- Caution if coadministered with other drugs known to prolong QT interval
- QTc prolongation reported with higher than recommended doses
- Geriatric patients may be more prone to QT prolongation
-
OATP and BCRP substrates
- Temsavir inhibits OATP1B1, OATP1B3, and BCRP
- Caution; OATP1B1/3 or BCRP substrates (eg, grazoprevir, voxilaprevir, ethinyl estradiol, statins) may need to be avoided or require dosage modification
- Temsavir inhibits organic anion transporting polypeptide (OATP)1B1/3, which may increase plasma concentration of substrate
Pregnancy & Lactation
Pregnancy
Antiretroviral pregnancy registry (APR): Clinicians are encouraged to register patients by calling 1-800-258-4263
Human data are insufficient regarding use during pregnancy to adequately assess a drug-associated risk of birth defects and miscarriage
Animal studies
- Oral administration to pregnant rats and rabbits during organogenesis resulted in no adverse developmental effects at clinically relevant temsavir exposures
Lactation
The CDC recommends that HIV-1–infected mothers in the United States not breastfeed their infants to avoid risking postnatal transmission of HIV-1 infection
Unknown if excreted in breast milk, affects milk production, or effects breastfed infants
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
Prodrug of temsavir; first-in-class HIV-1 attachment inhibitor that works by binding directly to the glycoprotein 120 (gp120) subunit on the surface of the virus
By binding to this location on the virus, fostemsavir blocks HIV from attaching to host immune system CD4+ T cells and other immune cells, thereby preventing HIV from infecting those cells and multiplying
Absorption
Bioavailability: 26.9%
Peak plasma time: 2 hr
Peak plasma concentration: 1700 ng/mL
Trough concentration: 478 ng/mL
AUC: 12,900 ng⋅h/mL
Distribution
Protein bound: 88.4% (primarily to albumin)
Vd: 29.5 L
Metabolism
Hydrolysis (esterases): 36.1%
Oxidation (CYP3A4): 21.2%
UGT: <1%
Elimination
Half-life: 11 hr
Clearance: 17.9 L/hr
Excretion: Urine (51%; <2% unchanged); feces (33%; 1.1 unchanged)
Administration
Oral Administration
May take with or without food
Swallow tablets whole; do not chew, crush, or split
Missed dose
- Advise patients to avoid missing doses as it can result in development of resistance
- If dose is missed; take as soon as remembered
- Do not double next dose or take more than prescribed dose owing to risk of QT prolongation
Storage
Store at 20-25ºC (68-77ºF); excursions permitted to 15-30ºC (59-86ºF)
Tablets may have slight vinegarlike odor
Images
Formulary
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.
