June 13, 2013
Study Says HIV Drug Tenofovir Also Helps Prevent Contraction Of The Virus
Brett Smith for redOrbit.com - Your Universe Online
New research from the Centers for Disease Control and Prevention suggests that a daily pill can prevent the contraction of HIV for intravenous drug users.
The four-year study, which was published in The Lancet, boosts the argument of those advocating a preventative strategy called “¯pre-exposure prophylaxis, or PrEP.
"This is a significant step forward for HIV prevention," Jonathan Mermin, a CDC spokesman who was not directly involved in the study, told the AFP. “We now know that PrEP can work for all populations at increased risk for HIV.”
"Injection drug use accounts for a substantial portion of the HIV epidemic around the world, and we are hopeful that PrEP can play a role in reducing the continued toll,” he added.
The study included 2,400 intravenous drug users in Thailand who were attending drug treatment clinics and did not test positive for HIV when the study began. The volunteers were divided into two groups: one was given a daily dose of the HIV drug tenofovir, while the other was given a placebo.
Both groups were offered monthly testing for HIV, condoms and treatments for their drug dependency. To encourage volunteers in a subject group that is notoriously unreliable, participants were given $8.75 for each month they kept participating in the study and an additional $8.75 for each week they came to the clinic on all seven days. They also received $1.90 for each day they appeared. Even those who only made monthly appearance at the clinic were paid to keep drug-use diaries.
After the four years, 17 individuals had become infected in the tenofovir group, and 33 in the control group — a 49 percent risk reduction. Those who adhered strictly to the drug regimen were 70 less likely to contract the virus, according to the study.
Researchers were unsure how the tenofovir translated into risk reduction as addicts have been known to both share needles as well as prostitute themselves for drug money.
“We should be under no illusions that these were real-world settings,” Mitchell Warren, executive director for AIDS-advocacy organization AVAC, told the New York Times.
The results of the study do suggest that antiretroviral drugs could be used as one of the weapons in the battle to prevent AIDS, which currently includes condoms, abstinence, sexual fidelity, male circumcision in Africa, and microbicide gels.
The preventative drug strategy could have the largest impact in Eastern Europe and Central Asia, where intravenous drug use accounts for up to 80 percent of infections. Many countries in those regions shy away from handing out clean needles or offering methadone based on political or religious beliefs.
However, that strategy would compete against other programs that are less costly in countries with limited government health budgets. The US is reportedly setting up studies to see which tactics work best in various neighborhood settings.
Some experts noted that the latest study may impact doctors´ decisions. For example, a doctor might place an intravenous drug user on a daily tenofovir regimen, just as some doctors do for promiscuous gay male patients, or uninfected patients who have regular sex with an infected partner.