Duration of Post-Exposure HIV Prophylaxis After Needle Stick Injury
The recommended treatment course for post-exposure HIV prophylaxis (PEP) after a needle stick injury is 28 days, regardless of the severity of exposure. 1
Timing of PEP Initiation
PEP should be initiated as soon as possible after the exposure:
- Ideally within 24 hours of exposure
- No later than 72 hours after exposure
- Do not delay the first dose pending HIV test results of the source patient
PEP Regimen Selection
Preferred Regimens for Adults and Adolescents:
- Bictegravir/emtricitabine/tenofovir alafenamide OR
- Dolutegravir plus (tenofovir alafenamide or tenofovir disoproxil fumarate) plus (emtricitabine or lamivudine) 2
Important Considerations:
- The specific regimen should be selected based on:
- Potential drug interactions
- Comorbidities
- Pregnancy status
- Known or suspected drug resistance in the source patient
Follow-up During PEP Treatment
Monitoring Schedule:
- Initial follow-up at 24 hours (in person or remote) after starting PEP
- Monitor for medication side effects throughout the 28-day course
- Laboratory monitoring for drug toxicity as indicated by the specific regimen
Common Side Effects:
- Nausea (26.5% of recipients)
- Malaise and fatigue (22.8%)
- These side effects are a major reason for non-completion of the full 28-day course 1
Adherence Challenges
Adherence to the full 28-day regimen is a significant challenge:
- Studies show 17-47% of healthcare workers do not complete the full course due to medication intolerance 1
- In one study, only 11% of healthcare workers documented completion of the full 28-day course 3
Strategies to Improve Adherence:
- Prescribe medications with fewer doses and fewer pills per dose
- Educate patients about the importance of completing the full course
- Offer anti-emetics and other supportive medications for side effects
- Provide ongoing encouragement and consultation by phone or office visit 1
Post-PEP Follow-up Testing
After completing (or discontinuing) PEP, HIV testing is recommended at:
- 4-6 weeks post-exposure
- 3 months post-exposure
- Some guidelines also recommend testing at 6 months 1
Special Considerations
Pregnant Women:
- PEP should not be withheld due to pregnancy
- Efavirenz should not be used in pregnant women or women who might become pregnant during the course of PEP 1
Immediate Actions After Exposure:
- Clean the wound site thoroughly with soap and water
- Report the incident according to institutional protocols
- Assess the source patient's HIV status when possible
- Initiate PEP without waiting for source patient test results if indicated
Conclusion
The standard duration of PEP after occupational needle stick exposure is 28 days. Despite challenges with medication side effects and adherence, completing the full course is essential to maximize the effectiveness of prophylaxis in preventing HIV infection.