A recent analysis of more than 3,000 HIV-positive patients suggests that, all other factors being equal, an HIV-positive patient who takes fewer pills is significantly more likely to show signs of improvement than one who must adhere to a more complex pill regimen.
The researchers and statisticians from the Medical Center and Triangle Pharmaceuticals who conducted the study said patients with fewer pills would be more likely to adhere strictly to their scheduled regimen.
"It's a significant undertaking for patients to be perfect on their regimens," said Dr. John Bartlett, director of clinical research at the Duke University Center for AIDS Research and associate professor of infectious diseases. "With fewer pills, it's easier for patients to take them."
Bartlett presented the findings in San Francisco last week at the Seventh Conference on Retroviruses and Opportunistic Infections.
The study, which analyzed the results of 22 independently conducted experiments dating back to 1995, included 3,115 patients whose daily regimens ranged from four to 16 pills.
The 13 drugs involved included protease inhibitors, nucleoside reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors. These classes of drugs, among those most commonly used to treat HIV-positive patients, all interfere with the virus' ability to replicate itself, but work at different stages in that process.
After 48 weeks, around 75 percent of the patients with the lowest pill counts had less than 50 copies of HIV RNA per milliliter of blood, a key indicator of the success of an anti-retroviral drug, said Bartlett. On the other hand, he said, only 20 percent of those with the highest pill counts met this same criterion.
While the drug regimens in the 22 original trials were of varying strength, the analysis corrected for these results, and still found that the pill count was a significant factor in the success of the treatments.
The study's conclusion-that lighter pill regimens would produce better results-was not particularly surprising to most scientists.
"It's a logical idea that everyone in the field has," said Dr. Thomas Merigan, professor of medicine and director of the AIDS Clinical Trials Unit at the Stanford University Medical Center. But he said the findings were still significant, because they confirmed this idea with scientific evidence.
The researchers involved in the study agreed. "It may have been what people expected," said Cary Moxham, director of HIV Clinical Research for Triangle Pharmaceuticals, which developed some of the drugs studied. "But... this is one of the first analyses that actually puts the proof in the pudding."
Bartlett concurred, calling the results "an important scientific confirmation of our common intuition."
The analysis was originally intended to study the effects of different triple-drug combinations, but the researchers found no significant differences between them. Therefore, they decided to investigate the relationship between pill burden and results.
Bartlett said that he hoped the findings would give doctors and HIV-positive patients more information with which to decide on an appropriate course of treatment. "These findings will help doctors to make choices," he said.
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