Truvada Retains Potent Protective Element Despite Variations in Patient Adherence

Patients taking Truvada may still significantly reduce their risk of HIV infection even when they are not 100% adherent to their drug regimens, a new study revealed.

Patients taking Truvada (emtricitabine/tenofovir disoproxil fumarate) as pre-exposure prophylactic (PrEP) do not have to follow perfect adherence in order to enjoy the protective benefits of the drug, new research from a group of HIV/AIDS experts suggests.

“After the initial iPrEx study, there was concern that the protective effect of Truvada was fragile, and that individuals taking the drug would need to adhere perfectly to a daily regimen for it to work,” said Robert Grant, MD, MPH, professor at the University of California, San Francisco, and a researcher at the Gladstone Institutes. “The new study suggests that Truvada can help block the virus even if the person on a daily regimen doesn’t always adhere perfectly.”

The study is the first of its kind to quantitatively measure the drug concentration levels in the blood and then correlate those levels with the drug’s effectiveness. Typically, adherence is measured through self-reported data—a method that can be extremely unreliable.

Investigators analyzed a cohort of 24 people without HIV taking 2, 4, or 7 doses per week of Truvada and compared their blood levels of the drug with the concentrations found in each of the original iPrEx study participants. Investigators tested 3 dosage levels in order to mimic the effects of the varying degree of patient adherence levels that most likely occurred with the participants of the original study.

Investigators concluded that the risk of contracting HIV decreased by more than 90% when patients took Truvada—even when they did not adhere perfectly to the prescribed dosage regimen. The researchers believe that this finding will help prescribers optimize dosing for each patient, which could result in more cost-effective treatment plans that are easier for patients to follow.

Although varying dosage levels were found to produce similar outcomes in this study, the researchers warned that patients should not alter the current regimen that is both recommended by the FDA and used in clinical practice. “Patients should still take 1 pill a day to achieve the best results, and we encourage people to explore multiple methods to prevent HIV—such as regular condom use, early treatment of HIV in partners, good communication, and male circumcision,” noted Dr. Grant.

For more information about Truvada as PrEP, view the following articles on Specialty Pharmacy Times:

-FDA Approves Truvada for HIV Risk Reduction

-Truvada Decision Delayed, Gilead Institutes New HIV Testing Guidelines

-FDA Panel Recommends Approval of Drug for HIV Prevention