UK updates PEP guidelines (2014): raltegravir replaces PIs and no indication if positive partner has an undetectable viral load
Simon Collins, HIV i-Base
The UK Chief Medical Officers’ Expert Advisory Group on AIDS (EAGA) has issued new guidance for Post Exposure Prophylaxis (PEP) that includes using raltegravir rather than a boosted protease inhibitor. 
The switch to raltegravir as the third active drug in PEP should improve tolerability. Fewer side effects may increase the number of people who come forward to use PEP. It could also increase the number of people who complete the monthly course of PEP as drop out rates are generally high.
Raltegravir is more rapidly absorbed, compared to PIs, and this may improve the chance that PEP is effective at stopping potential HIV infections.
Prescribing guidelines are also being updated to say the PEP is no longer indicated if the HIV positive partner has an undetectable viral load (<200 copies/mL) although also, somewhat unhelpfully, that “PEP should be offered to those who are anxious about the risk”.
This new guidance reflects the dramatic impact HIV treatment has on reducing the risk of transmission. Results from the PARTNER study reported no linked transmissions between sero-different partners after more than 44,500 times when sex occurred without using condoms. 
Although some clinics have already switched to the new combination a few centres may continue with existing stocks (using Kaletra). This should only be for a short period.
The BHIVA website reports that the guidelines for PEP after sexual exposure (PEPSE) produced by BASHH with input from BHIVA are currently being updated according to NICE-accredited guideline development processes and should be available in late 2014/early 2015.
- EAGA. EAGA guidance on HIV post-exposure prophylaxis.
- PARTNER Study
- BHIVA website. Change to the recommended regimen for post-exposure prophylaxis (PEP). (10 September 2014).