HIV Drug Resistance Not Patients' Fault
Best Patients Get Most Drug-Resistant HIV
Aug. 20, 2003 -- You can't blame patients for HIV drug resistance.
The AIDS virus is notoriously good at becoming resistant to anti-HIV drugs. It's common to blame patients who don't take their drugs exactly as prescribed. But that's wrong, a new study suggests.
Study leader David R. Bangsberg, MD, is director of the University of California, San Francisco Epidemiology and Prevention Interventions Center. His team studied HIV drug resistance and adherence to anti-HIV drug regimens in 148 patients. The study appears in the Sept. 5 issue of AIDS.
The surprising finding: Those who were best at taking their medicine were most likely to develop HIV drug resistance. There was relatively little drug-resistant virus in patients who weren't taking their medicine as prescribed.
"There's one clear message here," Bangsberg tells WebMD. "The relationship between drug resistance and adherence to anti-HIV drugs is complex. This does not mean patients with HIV should take less of their drugs. That would be the same as taking no medications at all -- and they would go back to the natural course of HIV infection, which we know is bad."
Medicine Takers Do Better
Robert Gross, MD, a researcher at the University of Pennsylvania center for clinical epidemiology and biostatistics, has studied the issue of adherence to anti-HIV drugs.
"Preventing resistance is important, but it is much more important to prevent disease," Gross tells WebMD. "Resistance is not a human outcome, it is a virus outcome. The human outcome is: Did a person get sick? And people who keep taking their anti-HIV treatment despite getting resistant virus do better than those who stop treatment."
Bad Virus, Good Patients
Bangsberg's team found that about half of the patients who took their HIV drugs exactly as they should had exactly the expected results. Their HIV levels got very low and stayed that way.
But the other half of the good patients didn't have quite such excellent results. Their HIV levels stayed low enough to protect them from disease -- but not low enough to keep the virus from slowly developing HIV drug resistance.
"Maybe their drug regimen is not potent enough, or maybe there are issues with how specific drugs work for specific patients," Bangsberg says. "Even with perfect adherence, half of our adherent patients have HIV that is incompletely suppressed. They have the most rapid evolution of resistance."
Bad Patients Still Worth Treating
It's sometimes argued that anti-HIV drugs shouldn't be offered to patients who won't take them as prescribed. That's a bunch of hooey, Bangsberg and Gross argue.
Both have published studies showing that doctors simply can't predict which patients will fail to follow doctors' orders. Now, they note, there's no compelling public health reason not to offer the drugs to anyone who wants them.