(Reuters Health) - Last month U.S. regulators said a pill that helps prevent infection with HIV is safe for use by adolescents, and a study suggests most physicians would be willing to prescribe this medicine to teens.

So-called pre-exposure prophylaxis (PrEP) with Truvada, a daily pill combining the medicines tenofovir and emtricitabine, can lower the risk of getting HIV from sex by up to 90 percent, according to the U.S. Centers for Disease Control and Prevention. Truvada has long been used to treat HIV and as a prevention strategy for adults.

The current study was conducted between October 2016 and January 2017, before the U.S. Food and Drug Administration approved PrEP for teens who weigh at least 35 kg (77 pounds).

Researchers surveyed 162 doctors who worked with adolescents and young adults. While 93 percent of the clinicians had heard of PrEP, only 35 percent had prescribed it.

About 65 percent of the survey participants said they would be willing to prescribe PrEP to adolescents, and another 19 percent were willing to refer teens to another clinician for the prescription.

Among those who were unwilling to prescribe it themselves, about two-thirds said they would prescribe it for teens if it had FDA approval for these patients.

“Everyone, including adolescents, should know whether they could benefit from PrEP,” said lead study author Dr. Geoffrey Hart-Cooper, a pediatrician at Stanford Children’s Health and a HIV prevention specialist at the San Francisco Department of Public Health.

Patients at the greatest risk who could benefit most from PrEP include young men and transgender men who have sex with men; people with HIV-positive sex partners or partners with unknown HIV status; and intravenous drug users, Hart-Cooper said by email.

Because sex practices can change over time, doctors should discuss this on a regular basis and continually reassess whether patients might benefit from PrEP, he advised.

“Having these early conversations with youth allows eligible adolescents and young adults to start PrEP earlier,” Hart-Cooper added. “If we continue to promote safe sex practices while ensuring every adolescent and young adult has access to PrEP in a timely manner, we can substantially decrease HIV rates - maybe even eliminate HIV in this generation.”

In the survey, more than half of the respondents said they had only treated a few teens and young adults with HIV. Just 15 percent of the clinicians reported treating many HIV-positive youth.

Beyond the timing of the study before PrEP won FDA approval for use in teens, another limitation of the study is that very few clinicians invited to participate in the survey chose to do so.

Still, the results suggest that some providers may still need to be educated about PrEP and made aware that it’s now approved for use in teens, said Matthew Beymer, a researcher at the University of California, Los Angeles, David Geffen School of Medicine and at the Los Angeles LGBT Center.

“I think the take-home message is that PrEP works well whether you are an adolescent (and over 77 pounds) or an adult provided you take your medication every day,” Beymer, who wasn’t involved in the study, said by email. “Teens should consider taking PrEP if they either have an indication for PrEP or feel that taking PrEP would reduce their concerns about contracting HIV.”

SOURCE: bit.ly/2lCdbZ3 Journal of Adolescent Health, online May 26, 2018.