Last reviewed 2026-04-23 · How we verify

PEP

PEP is an antiretroviral medication that inhibits the replication of retroviruses by blocking the action of the viral protease enzyme.

PEP is an antiretroviral medication that inhibits the replication of retroviruses by blocking the action of the viral protease enzyme. Used for Pre-exposure prophylaxis to prevent HIV infection, Treatment of HIV-1 infection.

At a glance

Mechanism of action

PEP works by binding to the protease enzyme, preventing it from cleaving viral proteins and thus inhibiting viral replication. This mechanism of action is specific to retroviruses, such as HIV, and is not effective against other types of viruses.

Approved indications

• Pre-exposure prophylaxis to prevent HIV infection
• Treatment of HIV-1 infection

Common side effects

• Nausea
• Diarrhea
• Fatigue
• Headache
• Dizziness

Key clinical trials

• Pharmacy-based PrEP Delivery in Kenya (NA)
• Studying Chemotherapy With or Without Panitumumab for Unresectable, Locally Advanced, or Metastatic Pancreatic Cancer Without KRAS Mutations (PHASE3)
• Improving Clinic Delivery of HIV-related Anal Health Services (NA)
• Predictors of Mental Health in Men With Prostate Cancer Undergoing a Patient Empowerment Program (NA)
• Spinal Cord Stimulation for Respiratory Rehabilitation in Patients With Chronic Spinal Cord Injury (NA)
• Developing mHealth to Promote PrEP Use Among Thai Young Vulnerable Adolescents and Emerging Adults (NA)
• PEP-CMV + Nivolumab for Newly Diagnosed Diffuse Midline Glioma/High-grade Glioma and Recurrent Diffuse Midline Glioma/High-grade Glioma, Medulloblastoma, and Ependymoma (PHASE1, PHASE2)
• Effectiveness and Implementation of Text Messaging to Improve HIV Testing in Adolescents (NA)

Primary sources

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