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NIH Seven-Day On-Off Trial May Reduce Drug Side Effects, Cost; Why It's Not Ready for Use

By John S. James

December 21, 2001

On December 4 researchers at the U.S. National Institute of Allergy and Infectious Diseases published an early report of their 7-day-on/7-day-off trial of antiretrovirals.1 This study found that a handful of selected patients, with a selected antiretroviral regimen, were able to use the drugs intermittently, with a schedule of 7 days on and 7 days off. They were able to maintain viral suppression for 32-68 weeks so far, with only half the drug use and clearly reduced side effects. The researchers emphasize that this regimen is not ready for use outside of controlled clinical trials. The reasons are explained in the article, but not in most news reports.

The Purpose of the Trial

The goal of this trial is to see if it is possible to maintain HIV suppression with a reduced amount of antiretroviral drugs, in order to reduce toxicity and cost. There is no effort in this study to improve the treatment by allowing some return of the virus in order to stimulate the body's immune system against it.

Instead, this trial started with the observation that when HIV is very well suppressed by antiretrovirals, and the treatment is interrupted, it usually takes 2-3 weeks for detectable virus to return. Since there is so little HIV replication in that first week (assuming, of course, that the virus had been very well controlled when treatment was stopped), there should be little chance for the virus to develop resistance in that first week off the drugs. Then the treatment would be started again, keeping the virus suppressed. So far it seems to be working in this 10-patient proof-of-concept trial.

Cholesterol decreased 22% in this study, and triglycerides decreased 51%, after 24 weeks of intermittent treatment -- probably because patients had less exposure to the drugs. The researchers do not expect much change in lipodystrophy, however.

Comment: Why It's Not Ready to Use

We are concerned that people may start trying treatment interruptions without medical advice, in cases when it is entirely inappropriate for them. Here are some facts to consider:


  1. Dybul M., Chun T., Yoder C., and others. Short-cycle structured intermittent treatment of chronic HIV infection with highly active antiretroviral therapy: Effects on virologic, immunologic, and toxicity parameters. Proceedings of the National Academy of Sciences USA, Early Edition online (December 4, 2001).

ISSN # 1052-4207

Copyright 2001 by John S. James. Permission granted for noncommercial reproduction, provided that our address and phone number are included if more than short quotations are used.

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