In switch study, women twice as likely as men to discontinue HAART due to toxicities

Barring resistance, highly active antiretroviral therapy (HAART) is usually very effective at suppressing HIV.

In many patients, this has led to remarkable, and once only dreamed of, immune recovery and improvements in quantity and quality of life. Still, many patients have difficulty with taking and/or tolerating HAART, and these problems have put a damper on the potential success of HAART.

Some studies have indicated that patients frequently discontinue or switch HAART regimens and in some studies the median duration of the initial HAART regimen has been an amazingly short 4 months. Of course, toxicities were often the main reason cited for discontinuation of therapy, and in one recent study women were twice as likely as men to discontinue HAART because of toxicities.

In a study reported in The Journal of Acquired Immune Deficiency Syndromes, investigators in the Women’s Interagency HIV Study (WIHS) described the variability in HAART regimens between 1994 and 2000 in 1056 HIV-positive and the prevalence of and calendar time associated with reported changes in HAART regimens between semiannual visits and evaluated factors associated with a first switch. In addition, the investigators compared disease markers among women switching or discontinuing HAART with those of women remaining on unchanged HAART regimens.

The investigators found that a 13-fold increase in the number of unique HAART regimens occurred during the study period. Further, they found that the amount of time spent by patients on their first, second, or third regimen was similar, with an 8-month median time to switching or discontinuing the initial HAART regimen.

One year after HAART initiation, the percentage of women estimated to have switched their initial HAART regimen was 65%. This estimate did not differ from the percentage of women switching 1 year after starting their second HAART regimen (62%) or from the percentage switching 1 year after starting their third HAART regimen (62%).

Using a multivariate analysis, factors associated with switching after HAART initiation were a higher pre-HAART viral load and ethnicity, with Hispanic and black patients more likely to switch than Caucasian patients. Further, women who switched had a lower mean CD4 cell count and were more likely to have a viral load >400 copies/mL. Overall, the percentage of women switching decreased over the course of the study (to 37% in September 2000), although the percentage discontinuing therapy altogether increased 2-fold.

The authors conclude, “Our findings on the relatively high rate of antiretroviral regimen switching emphasize the complexity of managing and evaluating these therapies. Clinicians must cope with limits on the number of therapeutic options, a fact largely the result of potential cross-resistance among drugs of a single class. The occurrence of side effects, patient nonadherence, and virologic failure may result in more frequent regimen switching, but this needs future study…

“Furthermore, these observational studies have a key role in evaluating optimal switching strategies and the long-term effects of switching in a setting complementary to clinical trials.”

Comment

Might physician inexperience and poor management of toxicities and or regimen switches be a factor here. Perhaps women, Hispanics and Blacks in this patient population were more likely to be attended by less experienced physicians?