Although research is ongoing, there is no available HIV vaccine to date. In the meantime, clinical trials are evaluating whether regular or preexposure use of antiretroviral therapy provides additional protection for HIV-negative persons at high risk of infection who are offered standard preventive care with advanced laboratory testing, including HIV testing, counseling, condoms, and management of sexually transmitted infections.

Currently, preexposure or post exposure prophylaxis involves the administration of ARV (HIV meications) to prevent the transmission of the virus either before or after the exposure.

The role of antiretroviral therapy (ART) in preventing HIV infection was first evaluated in pregnant women to decrease the risk of mother to child transmission (MTCT) and among healthcare personnel who had accidental needlestick exposures.

These limited data form the basis for the current recommendations for postexposure prophylaxis after sexual or injection drug use exposures.

• The overall risk of contracting HIV from any single exposure to body fluids from an HIV-infected patient from nonoccupational exposures is low.
• It is important to determine the exact nature of the HIV exposure (eg, unprotected sexual intercourse or injection drug use), which may confer varying levels of risk. For example, receptive anal intercourse carries a higher risk of HIV acquisition than other exposures, such as vaginal intercourse.
• Level of viremia (viral load) in the source patient and presence of genital lesions in the source or the exposed patient may augment HIV exposure risk significantly,
• Patient need to have a detailed discussion with his doctor about the potential risks and benefits of postexposure prophylaxis. The risk/benefit ratio of postexposure prophylaxis rises in patients with lower risk exposures (eg, fellatio versus anal intercourse)
• Patients must be aware of potential medication side effects and toxicity concerns.
• An example of high-risk exposure would include receptive anal intercourse with an untreated HIV-infected individual.
• Postexposure prophylaxis (PEP) should be started as early as possible after an exposure and should be continued for 28 days.
• PEP is not indicated if the patient presents for care more than 72 hours after an exposure.
• You should ask your specialist what is the more appropriate medication combination.