The only FDA approved treatment for the prevention HIV infection is once daily oral combined tenofovir disoproxil fumarate and emtricitabine; however, some studies have found that tenofovir disproxil fumarate monotherapy is also effective. Considering these trials, the CDC has suggested that tenofovir disoproxil fumarate monotherapy can be used as an alternative for men and women at high risk and those who inject drugs.
Tenofovir disoproxil fumarate/emtricitabine can also be used in pregnant patients, however the USPSTF notes that no PrEP trials included pregnant women. Additionally, tenofovir disoproxil fumarate/emtricitabine can be used in adolescents who weigh more than 35 kg. It is unknown how much time it takes to achieve protection against HIV infection after starting PrEP, and there is no clear timeline for how long patients should be on PrEP. Patients may discontinue medication because of preference, decreased risk of HIV exposure, or side effects.
Side effects include renal adverse events (serum creatinine rise), gastrointestinal adverse events (mostly nausea), and bone loss and increased fracture risk, although none were statistically significant when PrEP and placebo groups were compared. The USPSTF’s recommendations note that the effectiveness of PrEP is dependent on medication adherence.
While PrEP is an important part of preventing HIV, it is always important to counsel patients on other ways to reduce risk. The USPSTF notes that consistent condom use reduces the risk of HIV infection by around 80% in addition to reducing the risk of other STIs. All trials studied by the USPSTF for these recommendations included counseling on behavior, adherence, and condom use.
It is estimated that 1.1 million Americans are living with HIV and 15% are unaware that they are positive for HIV. Overall cases of new HIV diagnoses are down, but they are rising in some groups.
Dr. Skolnik is professor of family and community medicine at Jefferson Medical College, Philadelphia, and an associate director of the family medicine residency program at Abington (Pa.) Jefferson Health. Dr. Sprogell is a second-year resident in the Family Medicine Residency Program at Abington Jefferson Health
Owens DK et al. “Preexposure prophylaxis for the prevention of HIV infection: US Preventive Services Task Force recommendation statement.”.