Easier abacavir regimen has promising results

Patients improved adherence on abacavir

Coverage of the 2001 IDSA Conference

HIV patients, understandably, are sometimes unenthusiastic about taking their protease inhibitor (PI) drug therapies because of the numerous pills, the side effects, and chronic problems such as lipodystrophy. To address these problems, researchers have been studying non-PI drug therapies that are potent against HIV. An abstract presented at the 39th Annual Meeting of the Infectious Diseases Society of America (IDSA), held Oct. 25-28, 2001, in San Francisco, demonstrated successful viral suppression for at least 24 weeks when patients were switched from a PI regimen to an abacavir regimen.

"The reason we did this study was to try to address an issue that a lot of clinicians are running into, and that is the difficulty with chronic management of PI regimens," says Joseph J. Pulvirenti, MD, director of inpatient HIV services for Cook County Hospital in Chicago. "We were trying to achieve a decrease in adverse events and develop regimens that were more patient-friendly," Pulvirenti says.

Investigators selected patients who were on their first antiretroviral regimen and who had a good response to that regimen, remaining undetectable for a period of time, Pulvirenti says. Patients were placed in random groups with a two-to-one ratio: For every two patients who were discontinued on PI therapy and switched to an abacavir therapy, there was one patient who continued on the PI therapy, he explains. At 24 weeks, the two groups were compared with regard to viral load, adverse effects, cholesterol levels, triglyceride levels, and adherence.

Abacavir group maintained viral suppression

The study found that patients who had been switched to the abacavir regimen maintained viral suppression and adherence and had an improved lipid profile, Pulvirenti says. Both groups had improved their adherence during the study, and there was no significant difference in whether patients achieved an undetectable viral load, he says. However, the patients who had been switched to abacavir had an improvement in triglycerides and cholesterol levels, as well as improvement in adherence, which suggests this was a more tolerable regimen, Pulvirenti says. "If the study were carried out to 48 weeks or further, the study in adherence may have had more of an effect," he adds.

The abacavir group had to take only four pills a day, as opposed to PI regimens, which can require patients taking more than 10 pills per day, Pulvirenti notes. "There is more than enough data out there to suggest that swapping out is a perfectly viable way to go," Pulvirenti says. "When it comes to my patient population and people who are well-controlled but who remain on protease inhibitors, I discuss the options with them."

Some patients have refused to swap therapies, but Pulvirenti says he will discuss changing therapies for patients who have evidence of lipodystrophy or other problems that suggest greater risk for heart disease. "In order for a patient to get to the position where he can swap out, he has to be compliant with medication for a good long period of time," Pulvirenti notes. "So these people who are candidates for swapping regimens are generally very compliant and more highly educated than other patients." That’s why it’s essential to always obtain the patient’s opinion and discuss the plan for swapping medications, working toward obtaining patient buy-in for the strategy, Pulvirenti says.