AIDS Treatment Update, Issue 59, November 1997
Edward King

The analysis confirmed that viral load reductions after 8 weeks of treatment predicted the clinical benefits of the treatments, with the greatest reductions seen in the combination therapy arms. Throughout the first 48 and 96 weeks of the trial, the combination arms demonstrated better overall reductions in viral load than the AZT monotherapy arm.

However, combination therapy did not delay the emergence of AZT resistance. In fact, resistance to AZT developed faster among people taking AZT/ddI or AZT/ddC. There was little or no evidence of ddI or ddC resistance among people receiving those drugs in combination with AZT.

Clinicians increasingly see the prevention of drug resistance as an important priority in developing long-term anti-HIV therapy strategies. AZT resistance, as well as blocking the drug's anti-HIV effects, has been associated with a worse prognosis even after switching to a different treatment regimen. The Delta virology results would seem to suggest that AZT/ddI and AZT/ddC dual therapy regimens, while associated with clear clinical benefits compared with AZT alone, are not an effective way of avoiding AZT resistance.

971101
ATU5904

Copyright © 1997 - AIDS Treatment Update. Permission granted for noncommercial reproduction, provided that our address and phone number are included if more than short quotations are used. Subscription lists are kept confidential. NAM Publications 16a Clapham Common Southside, London, England SW4 7AB; TEL: 01-71-627-3200 (from outside the UK: +44-171-627-3200); FAX: 01-71-627-3101 (from outside the UK: +44=171-627-3101)  info@nam.org.uk  http://www.nam.org.uk