Researchers in Switzerland reported Monday that doctors can gauge how well their HIV-positive patients are responding to anti-HIV drugs--or if they're taking their medications as prescribed--by analyzing a sample of each patient's hair, Reuters Health reports. According to the researchers' study, published in the October issue of the Annals of Internal Medicine, hair samples contain traces of anti-HIV drugs that can be measured and linked with treatment efficacy. Hair samples that showed low levels of Crixivan, which was the drug studied by the researchers, were linked with patients who were not taking their medication consistently or who had trouble absorbing it into their bodies, both of which can lead to treatment failure and drug-resistant virus. High levels of the drug detected in the hair samples were linked with treatment success as measured by blood-based viral loads. The higher the amount the drug detected in the hair, the more likely the patient was to have undetectable blood-based viral loads, according to the study.
"Given the importance of long-term adherence to antiretroviral therapies for optimal outcome, hair analysis represents a significant, convenient, and affordable advance in assessing exposure to antiretroviral therapies over extended periods," wrote Monica Gandhi and Ruth Greenblatt of the University of California, San Francisco, in an editorial accompanying the study in the journal.