HIV Update: Researchers Develop New Technique in Measuring Patient's Adherence to Antiretroviral Drugs

A new technique developed by researchers from the Skaggs School of Pharmacy and Pharmaceutical Sciences at University of Colorado Anschutz could measure a patient's adherence to antiretroviral therapy.

Adherence to the antiretroviral therapy is very important in preventing the spread of HIV. Patient who are HIV-negative but displays a high risk of transmission were advised to take pre-exposure prophylactic, or PrEP, such as Truvada. Consistent used of PrEP could decrease the risk of HIV transmission during sex by 90 percent.

"There's a need to objectively measure PrEP adherence because traditional ways have not been very effective," explained Pete Anderson, Pharm.D. and professor of pharmaceutical sciences at the CU Skaggs School of Pharmacy in a press release. "This assay takes advantage of the long half-life of PrEP medication in red blood cells. This means the drug builds up in these cells only if the patient takes it consistently."

With the new technique, an absorbent paper-like card is used to spot a sample of the patient's blood. The dried blood will then be send in a laboratory, where the amount of PrEP drugs found in the dried red blood cells will be isolated and measured. By measuring the drug's presence in the patient's blood, the researchers could estimate how many doses a patient has taken over the last month or two.

"Most cell sample collections require significant effort for processing, but the dried blood spot is an easy sample collection technique. This helps with implementing the test in most settings," said Lane Bushman, lab manager at the CU Skaggs School of Pharmacy, in a statement.

The new technique is now being used in international labs focused on studying HIV transmission. Furthermore, the new techniques could also be used to monitor the adherence of patients to other drugs during their treatment, such as Hepatitis-C medication.

Centers for Disease Control and Prevention recommends people who area at high risk of HIV to take consistently take PrEP daily and have a regular check-up with their health care providers every three months.