Post-exposure prophylaxis

Overview

Medications commonly used in post-exposure prophylaxis

Post-exposure prophylaxis (PEP) is a medical treatment started immediately after exposure to a pathogen, such as a virus, in order to prevent infection and the development of disease. PEP is commonly used in the context of HIV exposure, but it is also applicable to other infectious diseases such as rabies and hepatitis B.

Mechanism of Action

PEP works by inhibiting the replication of the pathogen within the body, thereby preventing it from establishing an infection. The effectiveness of PEP depends on the timing of administration, the type of pathogen, and the specific medications used. For example, in the case of HIV, antiretroviral drugs are used to prevent the virus from multiplying.

Indications

PEP is indicated in situations where there is a significant risk of exposure to a pathogen. Common scenarios include:

• Occupational exposure, such as needlestick injuries in healthcare settings.
• Non-occupational exposure, such as unprotected sexual contact or sharing needles.
• Exposure to rabies through animal bites.

Administration

PEP should be initiated as soon as possible after exposure, ideally within hours. The treatment duration and specific medications depend on the pathogen involved. For HIV, a typical PEP regimen involves a combination of antiretroviral drugs taken for 28 days.

Side Effects

The side effects of PEP vary depending on the medications used. Common side effects include nausea, fatigue, and headache. It is important for patients to complete the full course of treatment despite these side effects to ensure effectiveness.

Effectiveness

The effectiveness of PEP is highest when administered promptly after exposure. Delays in treatment initiation can significantly reduce its efficacy. For HIV, PEP is most effective when started within 72 hours of exposure.

Related Pages

• HIV prevention
• Antiretroviral therapy
• Rabies vaccine
• Needlestick injury