Difficulties with HIV Treatment Adherence Raise Concerns About Drug Resistance
Solutions are urgently needed to help patients adhere to complex HIV treatment regimens over time, according to researchers at the Centers for Disease Control and Prevention (CDC).
Data presented today by CDC researcher Allyn Nakashima at the 12th World AIDS Conference finds that a substantial number of HIV-infected individuals report not adhering to combination therapy regimens as prescribed, and adherence lessens over time as the duration of treatment increases.
According to CDC, the potential dangers of non-adherence are serious, both for the health of infected individuals and for the future spread of the epidemic.
Clearly, new treatment regimens pose complex challenges for prevention. If people miss doses of their medication, they may be at increased risk for developing drug-resistant strains of HIV," said Helene Gayle, M.D., M.P.H., Director of CDC's National Center for HIV, STD, and TB Prevention. "If these strains are transmitted to others and spread widely, HIV infection could become again more difficult to treat.
Dr. Allyn Nakashima and colleagues analyzed adherence among over 1,200 HIV patients at select health facilities in twelve states. Researchers found that over three-fourths (81%) of these patients were taking antiretroviral therapies. Of these, about 90 percent were taking at least two antiretroviral drugs, and more than half (55%) were taking one or more protease inhibitors. These multiple medications must be taken several times each day. Some must be taken with food, and some must be taken on an empty stomach.
Only 65 percent of these patients report that they "always" take their medications as prescribed; 25 percent said they "usually" did; and 9 percent indicated that they "sometimes, rarely, or never" took their medications as prescribed. The most common reasons for not adhering to their therapy regimen were forgetfulness, difficulty working them into daily schedules, and side effects.
Researchers also found that patients were more likely to report that they "always" adhere to their medication regimen if they had been taking HIV treatments for less than 2 years, with adherence lessening the longer patients had been on therapy.
I think these findings remind us that medical advances don't work by themselves. With each new medical development for HIV prevention or treatment, we have to also consider how to help people use them effectively," said Nakashima. "Recognizing that some people may be taking these medications for many years, simpler schedules and formulations will be critical."
Nakashima stresses that in the interim, efforts must focus on ensuring that patients understand the necessity of taking medications and have the support they need to adhere to very difficult treatment regimens.
CDC believes that the possibility of emerging drug resistance, combined with the tendency individuals at risk may have to relax their preventive behaviors, poses a substantial risk. "The danger of complacency in HIV prevention may be greater than ever before," said Gayle. "We have to pay attention to prevention and work to prevent the emergence of resistant strains of HIV and to maintain the progress we've made to date in stemming the spread of this epidemic."
In a related presentation today, Nakashima examines issues related to access to the new treatment regimen, specifically regimens including protease inhibitors. Despite the substantial percentage of patients already taking protease inhibitors, the study finds that people of low socioeconomic status may still not have access to these highly effective, but expensive therapies. Patients in this study who were not on protease inhibitors were more likely to be African American, at less advanced stages of disease, and have incomes of less than $10,000 per year.
"Continuing efforts are needed to ensure that everyone has access to and can benefit from the most effective therapies," stressed Nakashima.