The Body: The Complete HIV/AIDS Resource
Follow Us Follow Us on Facebook Follow Us on Twitter 
Professionals >> Visit The Body PROThe Body en Espanol
Ask the Experts About

HIV Drug ResistanceHIV Drug Resistance
Rollover images to visit our other forums!
  • Email Email
  • Glossary Glossary

speed of resistance development
Jun 22, 2002

All things being equal between two individuals,both are on the same drugs miss the same number of doses(sporadically)but one has a high cd4 count(1000) the other 450.Will the lower count develop resistance faster?

Response from Dr. Little

The speed of drug resistance depends greatly on two different factors - the drug(s) in question and the viral load of the person taking the drugs. In general, the higher the viral load, the more rapidly drug resistance is likely to occur in a treated individual who has a detectable viral load. This is less dependent upon the CD4 cell count.

The second issue is the drug in question. There are certain drugs which are known to have a relatively low threshold for development of drug resistance - these are 3TC (lamivudine), and the non-nucleosides (efavirenz and nevirapine). Resistance to these drugs may occur in as little as 2 weeks. In contrast, resistance to a protease inhibitor may take several months to develop. It has to do with the number of changes in the virus that need to occur before drug resistance develops and how complete the resistance is with each subsequent change in the virus.

So - I don't think the CD4 cell count is as relevant and it really depends most heavily upon the viral load and drug type.

will atanazvir work?
Genotype & Phenotype

  • Email Email
  • Glossary Glossary



This forum is designed for educational purposes only, and experts are not rendering medical, mental health, legal or other professional advice or services. If you have or suspect you may have a medical, mental health, legal or other problem that requires advice, consult your own caregiver, attorney or other qualified professional.

Experts appearing on this page are independent and are solely responsible for editing and fact-checking their material. Neither nor any advertiser is the publisher or speaker of posted visitors' questions or the experts' material.

Review our complete terms of use and copyright notice.

Powered by ExpertViewpoint