How to Use Pills to Prevent HIV

Jan. 27, 2011 -- The CDC has issued early recommendations for the use of AIDS drugs to prevent HIV infection of men who have high-risk sex with men.

The preliminary guidelines follow last November's groundbreaking report that daily use of the AIDS drug Truvada lowers men's risk of HIV infection. This strategy, called pre-exposure prophylaxis or PrEP, can cut HIV risk by as much as 92% in men who take the pill every day.

But there's a catch. Several catches. For example:

• Truvada has to be taken every day, not just prior to sex.
• Truvada, like all HIV drugs, has side effects.
• Drug-resistant virus develops in men who begin PrEP when already infected with HIV.
• PrEP does not prevent other dangerous sexually transmitted diseases.
• Truvada is expensive. Since PrEP is not an FDA-approved use of the drug, insurance may not cover the cost.

U.S. public health agencies are developing PrEP guidelines. But since the news is out -- and men already are asking their doctors whether PrEP is right for them -- the CDC today issued preliminary guidelines.

Since PrEP was tested only in men (and male-to-female transgendered women), PrEP should be given only to biological males. Men eligible for PrEP should be at high risk of HIV infection -- that is, they should frequently change sexual partners or have concurrent partners in a region with high HIV prevalence.

Preliminary PrEP Guidelines

Here's the CDC's basic advice:

• PrEP should be offered only to HIV-negative men at high risk of HIV infection.
• PrEP should be just one part of a comprehensive prevention plan.
• PrEP must include regular HIV testing.
• Providers offering PrEP must regularly monitor patient adherence, drug side effects, and HIV risk behaviors.
• The only PrEP drug regimen tested is once-daily Truvada; other anti-HIV drugs should not be substituted.

Before starting PrEP:

• Test for HIV, including a sensitive test for recent infection if there are any symptoms of acute HIV infection.
• Check for normal kidney function.
• Test for hepatitis B infection.
• Test for sexually transmitted diseases.

When starting PrEP:

• Take one Truvada tablet every day.
• Providers should prescribe no more than a 90-day supply, renewable only when HIV testing is negative.
• Providers should offer counseling on reducing HIV risk behavior and on Truvada adherence.
• Providers should offer condoms.

During PrEP:

• HIV testing should be done every two to three months.
• Test regularly for sexually transmitted diseases.
• Providers should perform regular lab tests to evaluate Truvada side effects.

When PrEP is discontinued:

• Test for HIV.
• If HIV test is positive, evaluate whether virus is drug-resistant.
• If HIV test is negative, men should be referred to appropriate HIV prevention services.

The CDC's full preliminary PrEP guidelines appear in the Jan. 28 issue of Morbidity and Mortality Weekly Report.