Alcohol & Drug Abuse: Adherence to Complex Combination Antiretroviral Therapies by HIV-Positive Drug Abusers

The efficacy of the new combination antiretroviral therapies for treating HIV-positive individuals is unprecedented. Treatment has produced sustained suppression of viral replication and decreases in virus load to a level at which viral particles are undetectable in the blood of HIV-positive individuals. These therapies have resulted in a dramatically improved clinical outcome.

An important current issue is the ability of recovering drug abusers who are HIV-positive and living in poverty to adhere to these new complex and demanding regimens. Many clinicians believe that this group is too unreliable to take these medications, particularly in the early stage of their recovery from drug abuse when they are vulnerable to relapse (1).

The promise of highly effective antiretroviral therapy depends entirely on adherence to regimens that require at least 18 pills or capsules—some requiring refrigeration—taken on structured time lines, with food in some instances and on an empty stomach in others. If rigid adherence to medication schedules and food intake is not maintained, the virus may mutate and drug resistance or cross-resistance may develop (2), a devastating consequence for the individual. Less than excellent adherence can also have serious consequences for the community due to the transmission of drug-resistant HIV by nonadherent individuals and the increased virulence of the mutated strains. With the widespread introduction of these combination therapies into mainstream medical practice, nonadherence introduces an increasing risk of a second epidemic of more virulent, drug-resistant HIV strains.

Because of the recent development of combination antiretroviral therapies, the literature on adherence to HIV antiretroviral adherence focuses largely on AZT adherence. In non-drug-dependent populations, AZT adherence has ranged from 26 to 94 percent (3,4,5,6). Adherence rates are likely to be lower with the more complex combination therapies. One recent study found that adherence to HIV medications (including AZT), which was defined as the patient's refilling more than 80 percent of pharmacy prescriptions, was 63 percent in a multiethnic sample of veterans (7). Adherent patients tended to be other than black (p<.10), with lower scores on the Beck Depression Inventory (p<.04) and on the Profile of Mood States Total Mood Disturbance scale (p<.02). They used more adaptive coping skills (p<.03) and had more social support.

In another study, treatment nonadherence to antiretroviral medications (including AZT) among AIDS patients was associated with more distress and feelings of helplessness (8). Moreover, adherence was associated with better physical health status, based on Karnovsky scores collected at a 12-month follow-up.

A recent literature review suggested that the study of adherence to combination therapies among HIV-positive drug abusers has been largely neglected (9). In the few studies of this group, AZT adherence was reported to be greater among those whose medication ingestion was supervised and those with fewer psychiatric problems (10,11). Another research group found that better adherence to an AZT regimen was associated with greater social stability, greater perceived social support, increased perceived benefits of AZT use, and fewer perceptions of barriers to use (12). Our research group in Miami has reported that inconvenience and lack of access may play an important role in medication nonadherence among street-recruited HIV-positive drug abusers in Miami (13).

This column summarizes two preliminary studies that we conducted in 1997 to guide our effort to develop a brief intervention to enhance adherence to combination antiretroviral therapies among predominantly poor drug-abusing men.