How to take PEP (post-exposure prophylaxis) medication
Dec 03, 2025
Source: Cainiu Health
Dr. Huang Yuhong
Introduction
Post-exposure prophylaxis (PEP) should generally be initiated as early as possible, administered at fixed doses and frequencies, taken continuously, with attention to potential drug interactions and accompanied by dietary adjustments. The effectiveness of PEP is closely related to timing—the earlier it is started, the better the outcome. After a high-risk exposure, it is recommended to initiate treatment within 72 hours, ideally taking the first dose within 2 hours, to ensure the medication acts before viral replication begins.
Post-exposure prophylaxis (PEP) medications generally need to be taken as early as possible, at fixed doses and frequencies, continuously, with attention to drug interactions and dietary adjustments. The details are as follows:
1. Take medication as early as possible: The effectiveness of PEP is closely related to timing—the earlier it is started, the better the outcome. After a high-risk exposure, medication should ideally begin within 72 hours, with the first dose preferably taken within 2 hours to ensure the drug acts before HIV replication begins.
2. Fixed dosage and frequency: PEP typically involves multiple antiviral drugs that must be taken at specific doses and intervals. Patients should understand how each medication should be taken and strictly follow medical instructions without altering the dose or schedule on their own.
3. Continuous use: PEP must be taken daily for 28 days to maintain effective drug concentrations in the body and prevent HIV replication. Patients should take their medication on time, avoiding missed doses or treatment interruptions, as stopping prematurely may lead to PEP failure.
4. Watch for drug interactions: If patients are taking other medications, they must inform their doctor to avoid potential drug interactions that could reduce PEP effectiveness. When necessary, the doctor may adjust the treatment plan to ensure safety and efficacy.
5. Dietary adjustments: During PEP treatment, patients should maintain a balanced diet and avoid spicy, irritating foods and alcohol, which may interfere with drug absorption and metabolism. Proper nutrition helps strengthen immunity and increases the likelihood of successful prevention.
During PEP treatment, it is recommended to set alarms as reminders for timely dosing and to carry medication when traveling. If a dose is missed, it can be taken within 2 hours; if more than 12 hours have passed, do not take a补服 but inform the doctor immediately.
