Pharmacists Should Watch for Medication Sharing Among HIV Patients

Patients who enroll in studies, including those for pre-exposure prophylaxis (PrEP), may share their medication with friends and family who have health concerns of their own or the same diagnoses.

Product sharing in clinical trials compromises the ultimate findings by reducing the apparent efficacy of the active medication, blending the active and placebo arms, and manipulating the pill counts. Now, an article published ahead-of-print in AIDS and Behavior provides insight on product sharing and its impact on real-world adherence.

The Vaginal and Oral Interventions to Control the Epidemic (VOICE) trial studied the safety and efficacy of a 1% tenofovir vaginal gel, oral tenofovir, and oral emtricitabine and tenofovir disoproxil fumarate (Truvada) in women.

The investigators randomized 5029 women evenly into 5 arms: 1% tenofovir vaginal gel, placebo gel, oral tenofovir disoproxil fumarate, oral Truvada, or oral placebo. They provided participants with just enough study medication to last until the next visit, and they asked the subjects to return any unused products.

Pharmacists who dispensed medication could identify patients’ medications by study arm or the patient-specific identifier on the product. The investigators also reduced unintentional product sharing with color-coded stickers to prevent accidental mixing of stock with another study participant in the same household.

The researchers found that some patients returned product that they shouldn’t have had, as the researchers hadn’t dispensed it to them.

Product sharing was confirmed at 18 visits and suspected in 14 more. The study pharmacists either ruled out a dispensing error or obtained confirmation that the participant gained the medication from another participant.

The majority of product sharing (62.5%) was between family members both in and outside the trial cohort. Participants shared vaginal gel products more often because of both decreased social stigma associated with its use and perceived sexual pleasure benefit.

The researchers indicated that nonadherence could be higher than they reported using a voluntary return process because some patients probably did not return products in order to appear adherent.

Pharmacists should reinforce the importance of avoiding product sharing with patients in clear language they understand. The study authors recommended PrEP monitoring strategies in the real-world setting to ensure adherence.