The summary below is from the full report titled "Relationship between Levels of Indinavir in Hair and Virologic Response to Highly Active Antiretroviral Therapy." It is in the 15 October 2002 issue of Annals of Internal Medicine (volume 137, pages 656-659). The authors are L Bernard, A Vuagnat, G Peytavin, MC Hallouin, D Bouhour, TH Nguyen, JL Vildé, F Bricaire, G Raguin, P de Truchis, D Ghez, M Duong, and C Perronne.
Human immunodeficiency virus (HIV) infection interferes with a person's immune system. Fortunately, treatment with combinations of several anti-HIV drugs greatly improves health outcomes for people with HIV infection. Unfortunately, patients have difficulty taking the drugs correctly. Treatment success depends heavily on patients' taking the anti-HIV drugs exactly as prescribed and absorbing appropriate amounts of the drugs. Low levels of the drugs in the patient's body can be due to missed doses or to problems with absorption of the drugs into the body. Patients who miss doses of anti-HIV drugs or who do not absorb the drugs adequately can develop resistant forms of the virus. "Resistant" means that the drugs no longer effectively fight the virus. Measuring the levels of drugs in the blood and asking patients about missed drug doses are not accurate ways to tell whether patients took and absorbed the anti-HIV drugs over previous months. Doctors need better ways of testing to see whether patients with HIV infection have appropriate levels of the drugs.
To see whether measuring levels of anti-HIV drugs in patients' hair might be useful for determining that patients are taking and absorbing the drugs appropriately.
89 patients with HIV infection who were just beginning highly active anti-HIV drug regimens that included the anti-HIV drug indinavir.
The researchers measured indinavir levels in samples of patients' hair. They also took blood samples to measure levels of HIV and to see if the virus had developed changes that would make it resistant to anti-HIV drugs such as indinavir. Low levels of virus in the blood showed that a patient was responding to treatment.
Indinavir levels in the hair of patients who responded to treatment were higher than the levels in patients who were not responding to treatment. High indinavir levels in hair were also associated with less resistant virus.
Although this study measured blood levels of virus and determined resistance using laboratory tests, it did not look at the extent to which hair levels of indinavir were associated with whether patients developed illnesses related to HIV infection.
Measuring the levels of anti-HIV drugs in patients' hair may offer a new method for monitoring whether patients are taking appropriate amounts of the drugs.
Published: Ann Intern Med. 2002;137(8):I-48.