Human immunodeficiency virus (HIV) prevention (or prophylaxis) includes both safe sex practices and medications.
HIV can be spread through blood, semen, vaginal fluid, or breast milk. It is most often spread through sexual contact. Therefore, an important part of HIV prevention is practicing “safe sex.” This involves using condoms and asking about (or being tested for) HIV and other sexually transmitted infections before any type of sex with a new partner.
In some specific situations, medications can also be used to prevent HIV. These medications are antiretroviral (anti-HIV) pills. These pills are taken by people who do not have HIV infection but are at high risk of becoming infected. There are 2 types of HIV prophylaxis that involve the use of medications: preexposure prophylaxis and postexposure prophylaxis.
In preexposure prophylaxis, someone who does not have HIV infection takes 1 anti-HIV pill every day (a combination of 2 antiretroviral medications) as long as he or she is at high risk of getting infected with HIV. The medication can be taken for months or years. Those who may benefit from preexposure prophylaxis include
People who are in a relationship with a partner who has HIV infection.
People who have many sexual partners and do not regularly use condoms. This can include men and women and heterosexual, gay, or bisexual people.
People who inject drugs.
Individuals who take preexposure prophylaxis still need to be regularly tested for HIV. The use of preexposure prophylaxis is still fairly new in the United States. The Centers for Disease Control and Prevention recently released its first set of full guidelines for preexposure prophylaxis use in May 2014.
Postexposure prophylaxis is used when someone who does not have HIV infection experiences a specific event during which HIV exposure might have happened. Examples include when health care workers accidentally come into contact with blood or body fluids of a patient who may be infected with HIV (eg, from a needlestick injury); cases of sexual assault; and cases of unplanned, unprotected sex with someone who might have HIV infection.
Postexposure prophylaxis involves taking 2 or 3 anti-HIV pills every day for 4 weeks after the exposure event. Postexposure prophylaxis should be started as soon as possible and within 3 days of the exposure. Because there are more medications included in postexposure prophylaxis than in preexposure prophylaxis, it can have more side effects than preexposure prophylaxis. Unlike preexposure prophylaxis , postexposure prophylaxis is meant to be used in rare situations and not to be used repeatedly or for longer than 4 weeks.
Both preexposure and postexposure prophylaxis significantly lower the chance of HIV infection. But neither is 100% effective at preventing HIV infection. Smart prevention behaviors such as always using condoms and never sharing needles are still extremely important. Preexposure and postexposure HIV prophylaxis will not protect against other sexually transmitted infections.
To find this and previous JAMA Patient Pages, go to the Patient Page link on JAMA’s website at jama.com. Many are available in English and Spanish.
Topic: Infectious Disease
Jin J. Medications to Prevent HIV Infection. JAMA. 2014;312(4):452. doi:10.1001/jama.2014.8191