United States guidelines

The United States government announced new public health guidelines for the use of non-occupational post-exposure prophylaxis (PEP) in January 2005.¹ The guidelines recommend treatment for people who seek PEP no more than 72 hours after a high-risk exposure, such as through unprotected sex or sharing injecting equipment.

Unlike the United Kingdom guidelines, the guidelines from the United States state that any triple-drug antiretroviral regimen approved by the Department of Health and Human Services may be used. They also suggest that a dual nucleoside reverse transcriptase inhibitor (NRTI) regimen may be sufficient, as there is no evidence for the increased effectiveness of an extra drug, particularly in the face of increased risk of side-effects.

Preferred regimens include efavirenz (Sustiva) with 3TC (lamivudine, Epivir); or FTC (emtricitabine, Emtriva) and AZT (zidovudine, Retrovir) or tenofovir (Viread); and ritonavir-boosted lopinavir (Kaletra) with AZT and either 3TC or FTC. This may be modified if details of the source patient’s treatment history or resistance profile become available. The United States guidelines recommend the avoidance of efavirenz in women of childbearing age and nevirapine in general.

The United States guidelines recommend follow-up for at least six months following exposure to monitor for HIV infection, hepatitis B, hepatitis C, sexually transmitted infections, pregnancy, and/or drug toxicity when applicable.

While European and United States guidelines agree that treatment should be given for 28 days and when the source is known to be HIV-positive, they differ in situations where the source’s HIV status is unknown. European guidelines recommend treatment following unprotected receptive anal sex or following unprotected anal, vaginal or oral sex with ejaculation with a person from a group or an area of high HIV prevalence (more than 15%). If the source is not from a group or an area with a high HIV prevalence, PEP is only recommended following unprotected receptive anal sex.² In contrast, the United States recommendations suggest that the decision to administer PEP be made on a case-by-case basis.