fostemsavir (Rx)

Brand and Other Names:Rukobia
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Dosing & Uses

AdultPediatric

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

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Interactions

Interaction Checker

and fostemsavir

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            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 (5)

            • 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.

            • 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.

            • 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.

            • rimegepant

              fostemsavir will increase the level or effect of rimegepant by Other (see comment). Avoid or Use Alternate Drug. Fostemsavir inhibits BCRP transporters.

            • 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.

            Monitor Closely (200)

            • 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. QTc prolongation reported with higher than recommended doses of fostemsavir.

            • 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.

            • 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.

            • 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

              fostemsavir will increase the level or effect of ombitasvir/paritaprevir/ritonavir & dasabuvir 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.

            • 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.

            • 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.

            • 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.

            • ziprasidone

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

            Minor (0)

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              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
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              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
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              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.

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              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)

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              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

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              Images

              No images available for this drug.
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              Patient Handout

              A Patient Handout is not currently available for this monograph.
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              Formulary

              FormularyPatient Discounts

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

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

              Adding plans allows you to:

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

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

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