Effects of Recreational Drug Use in Patients Taking HAART

FEBRUARY 07, 2017
Jeannette Y. Wick, RPh, MBA, FASCP

Recreational drug use has been established as a risk factor for HIV acquisition, and many patients will find lifestyle modification—eschewing recreational drug use—difficult.  However, little research has tried to assess illicit drug use’s effect on patients living with HIV undergoing highly active antiretroviral therapy (HAART). 
A team of researchers in Barcelona, Spain examined patients receiving HAART to determine the prevalence of illicit drug use. 
Clinical pharmacists administered a questionnaire that included sociodemographic variables, past 12-month drug use, adherence to antiretroviral therapy, and high risk sexual behavior.  Overall, 92 of 208 patients reported consuming drugs over the previous year, and 50% reported a relevant interaction with their medications. 
The researchers identified similar patterns of drug consumption among patients receiving different HAART regimens, suggesting that clinicians do not consider drug use during therapy selection. 
While several mechanisms have been identified, most interactions occur through the cytochrome P450 (CYP) system. Protease inhibitors and pharmacokinetic-boosted regimens are potent CYP inhibitors that cause accumulation of medicinal and recreational drug metabolites.
Pharmacists may find a new term informative. HAART-illicit drug combinations can cause harm through drug overdoses, and by discouraging medication adherence due to interactive toxicity belief. This is an uninformed patient self-management behavior in which patients anticipate, delay, or miss their antivirals when they use illicit drugs.
Adherence to HAART medications is essential for efficacy, but patients who use recreational drugs have more issues with adherence. The effects on adherence are thought to be multifactorial. They include memory impairment, disruption of daily routines, and intentionally missing doses to avoid a potential interaction, whether one exists or not.
Despite the disparity in adherence, greater than 80% of patients who reported using recreational drugs had undetectable viral loads. This challenges the assertion that recreational drug use is detrimental to HAART efficacy. 
Recreational drug use is especially high in patients receiving antiretroviral therapy and was associated with lower adherence and high risk sexual practices. This may lead to a higher incidence of therapeutic failure. Clinicians should discuss recreational drug use with their HIV patients undergoing treatment to address any concerns and mitigate any potential harm. 
This article appears in BMJ Open.
Garin N, Zurita B, Velasco C, Feliu A, Gutierrez M, Masip M, Mangues MA. Prevalence and clinical impact of recreational drug consumption in people living with HIV on treatment: a cross-sectional study. BMJ Open. 2017 Jan 18;7(1):e014105.