Drug reference

fostemsavir

Entry Inhibitor · Antiretroviral

Entry InhibitorAntiretroviral

CDSCO approved

EXCRETION

—

not curated

INTERACTIONS

12 major

SEVERE in our sources

PREGNANCY

—

not curated

Top interactionssee all 12 →

AmiodaroneSevereDatabaseDDInter
AmisulprideSevereDatabaseDDInter
AnagrelideSevereDatabaseDDInter
ApalutamideSevereDatabaseDDInter

Mechanism

Fostemsavir is a methylphosphate prodrug that is rapidly hydrolyzed to temsavir. Temsavir binds to the viral envelope protein gp120, preventing its attachment to CD4 and subsequent cell entry.

Indications

heavily treatment-experienced adults with multidrug-resistant HIV-1 infection

Pharmacokinetics

Half-life

7–14

Metabolism

esterases, CYP3A4

Excretion

51% (renal, unchanged)

Side effects

Common

elevations of hepatic transaminases

Serious

QTc prolongation

Drug interactions

Amiodarone

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Amisulpride

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Anagrelide

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Apalutamide

Severe

Database

Drug interaction classified as: metabolism

Source: DDInter

Arsenic Trioxide

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Bedaquiline

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Bepridil

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Cabozantinib

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Carbamazepine

Severe

Database

Drug interaction classified as: metabolism

Source: DDInter

Ceritinib

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Chloroquine

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Cisapride

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Related guidelines

Antiretroviral therapy for HIV

NACO · Infectious Diseases · 2018

Skin and soft tissue infections

IDSA · Infectious Diseases · 2010

Hepatitis B — chronic infection

EASL · Gastroenterology · 2025

Urinary tract infection

EAU · Urology · 2024

Latent tuberculosis infection

RNTCP · Infectious Disease · 2023

Other Entry Inhibitor drugs

ibalizumab

0 brands

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Sources: Goodman & Gilman 14e·Verified: 2026-05-10 · House clinical team