What is the recommended dosing for Post-Exposure Prophylaxis (PEP) medication for Human Immunodeficiency Virus (HIV)?

From the Guidelines

HIV post-exposure prophylaxis (PEP) should be initiated as soon as possible after potential exposure, ideally within 72 hours, with a preferred regimen of tenofovir disoproxil fumarate (TDF) 300 mg plus emtricitabine (FTC) 200 mg once daily, combined with raltegravir 400 mg twice daily or dolutegravir 50 mg once daily, for a duration of 28 days. This recommendation is based on the 2016 guidelines from the International Antiviral Society-USA panel, published in JAMA 1. The guidelines emphasize the importance of prompt initiation of PEP, as efficacy decreases significantly when started later than 72 hours.

Key Considerations for PEP

• Baseline assessments should include HIV antibody testing, sexually transmitted infection testing, pregnancy testing for women of childbearing potential, and hepatitis B and C serologies.
• Alternative regimens may include TDF/FTC plus darunavir 800 mg with ritonavir 100 mg once daily, as recommended by the Centers for Disease Control and Prevention 1.
• PEP should be continued for 28 days, and HIV serostatus should be reassessed 4 weeks to 6 weeks, 3 months, and 6 months after exposure, although shorter serologic follow-up may be possible if using a fourth-generation assay 1.
• Persons who repeatedly seek PEP should be considered for pre-exposure prophylaxis (PrEP), as daily PrEP may be more protective than repeated episodes of PEP 1.

Monitoring and Follow-up

• Patients should be monitored for medication side effects, which commonly include nausea, fatigue, and headache.
• Follow-up HIV testing is recommended at completion of the 28-day regimen and again at 3 months post-exposure.
• The mechanism of action of PEP involves inhibiting viral replication through different mechanisms, including nucleoside reverse transcriptase inhibitors (TDF/FTC) and integrase inhibitors (raltegravir/dolutegravir) 1.

From the Research

HIV PEP Medication and Dosing

• The standard dosing for HIV PEP medication varies depending on the specific regimen, but most studies recommend a 28-day course of treatment 2, 3, 4, 5.
• One study found that a single tablet daily regimen of elvitegravir/cobicistat/tenofovir disoproxil fumarate/emtricitabine had higher completion rates compared to more frequently dosed regimens 2.
• Raltegravir, tenofovir DF, and emtricitabine have been shown to be a safe and effective regimen for PEP, with high adherence rates and minimal side effects 3, 4, 5.
• The most common side effects reported with PEP regimens include nausea, diarrhea, headache, fatigue, and abdominal symptoms, but these are typically mild and self-limited 2, 3, 4, 5.

Regimen Completion Rates

• A study comparing ritonavir-boosted lopinavir versus raltegravir each with tenofovir plus emtricitabine for PEP found that the raltegravir arm had higher regimen completion rates and lower rates of adverse events 4.
• Another study found that raltegravir-emtricitabine-tenofovir had high regimen completion rates and adherence rates, with minimal side effects 5.
• A study evaluating elvitegravir/cobicistat/tenofovir disoproxil fumarate/emtricitabine found that 71% of participants completed the 28-day regimen, which was significantly higher than historical controls 2.

Safety and Tolerability

• Raltegravir has been shown to be well-tolerated and safe for use in PEP regimens, with minimal side effects and no significant drug interactions 3, 4, 5.
• Elvitegravir/cobicistat/tenofovir disoproxil fumarate/emtricitabine has also been found to be safe and well-tolerated, with high regimen completion rates and minimal side effects 2.
• Nurse practitioners play an essential role in managing treatment for people exposed to HIV and following up on these patients' response and adherence to the treatment protocol 6.