PrEP is a once-daily pill designed to prevent HIV infection in high-risk individuals. According to the CDC, it can reduce the risk of HIV transmission from sex by more than 90%, and more than 70% among injection drug users.
Although Truvada (tenofovir/emtricitabine) is FDA approved for daily use in adults, it has yet to be indicated for adolescents under 18 years.
“Several studies have shown that daily oral PrEP is effective in preventing HIV among people at high risk of becoming infected, but none of them included adolescents under age 18,” study author Bill Kapogiannis, MD, said in a press release. “Our study suggests that this therapy can safely reduce HIV risk for those under 18.”
Included in the study, titled Adolescent Medicine Trials Network for HIV/AIDS Interventions, were 72 HIV-negative participants aged 15 to 17 years who were considered at-risk for HIV. Factors included unprotected sex with a male partner with HIV or whose HIV status was unknown, having at least 3 male partners, or having a sexually transmitted infection other than HIV.
The study was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institute on Drug Abuse, and National Institute of Mental Health.
During the study, participants received periodic tests for HIV and other STDs, counseling, and other interventions to help avoid risk behaviors. They also received Truvada once daily for 48 weeks.
Throughout the 48 weeks, many participants skipped doses of their medication, according to the release. Sufficient levels of Truvada to prevent HIV infection were detected in 54% of participants by week four, 49% by week twelve, 28% by week twenty-four, and 22% by week 48.
The primary reason for skipping doses was fear of others seeing them taking the medications and assuming they were HIV-positive. Other reasons included being away from home, too busy, forgetting, and changes in routine, according to the release.
Overall, Truvada was well-tolerated among participants, with no reported effects on the kidneys or bones. Three participants were diagnosed as having HIV during the study, all of whom had undetectable blood levels of Truvada at the visit before they were first diagnosed.
Based on the findings, the authors concluded that the “lack of significant adverse health events during the study indicated that the drug is safe for males under age 18,” according to the release. “Similarly, the lack of HIV infection among participants who had sufficiently high blood levels of medication is consistent with studies in adults and suggests that the drug can be effective in this population when taken appropriately.”