(RxWiki News) People at high risk for developing HIV can now take a medication to help prevent the disease. But to get the greatest protection from this medication, strict conditions must be followed.
The CDC has recommended a medication containing both tenofovir and emtricitabine (brand name Truvada) for use in people at high risk of HIV infection.
Clinical studies have shown the medication to be very effective at protecting against infection with the HIV virus, but the medication must be taken daily. Missed doses decreased protection against the virus.
People who take the medication must see their doctor every three months because if they do develop an HIV infection, different medications will be prescribed.
"Ask your doctor how to prevent an HIV infection."
A group of medical experts, led by the CDC, issued guidelines for treating groups of people at high risk for becoming infected with HIV. A medication combination was recommended for these high-risk individuals to protect against infection.
The preventive medication contains 300 milligrams of tenofovir disoproxil fumarate (TDF) and 200 milligrams of emtricitabine (FTC). This combination is referred to as TDF/FTC.
Treatment with TDF/FTC before exposure to the HIV virus is meant to protect against the development of infection. The treatment is referred to as pre-exposure prophylaxis (protection).
The high-risk groups for which this medication is recommended include the following:
- Sexually active men who have sex with men without a condom
- Heterosexual men and women who have sex with partners without using a condom
- Heterosexual men and women whose sexual partner is known to have HIV
- People who inject drugs
Studies have shown that the medication combination can reduce the risk of HIV infection in high-risk people.
A clinical trial of this treatment was done on men who reported having sex with a man during the six months before they entered the trial. The study showed that men who took TDF/FTC daily had a 92 percent decreased risk of getting an infection with HIV compared to men who had not taken TDF/FTC.
A study of heterosexual men and women found a 90 percent decreased risk of HIV infection among participants who took TDF/FTC daily compared to those who had not taken the medication.
Clinical trials involving intravenous (injected) drug users found a 73.5 percent decrease in the risk of HIV infection in those who took TDF (alone) compared to those who had not taken TDF.
The CDC guidelines stated that even greater protection can be provided to people taking the medication if they wear a condom during sex.
The guidelines recommended that doctors test their patients for HIV before prescribing this pre-exposure prophylaxis. People with HIV are not eligible to take the medication.
Doctors are advised to have their patients return for HIV testing every three months because if the patient does get an HIV infection, the medication will not treat it adequately.
The guidelines also recommended that doctors discuss the importance of taking the medication on a daily basis, as well as sexual and drug use behaviors that may increase the risk of HIV infection.
The authors of the guidelines stressed that the greatest protection against HIV infection can only occur when TDF/FTC is taken exactly as prescribed — once a day, every day.
These pre-exposure prophylaxis guidelines were published May 14 by the US Public Health Service.