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

Choosing Your MedsChoosing Your Meds
Rollover images to visit our other forums!
  • Email Email
  • Glossary Glossary

Sustiva causing resistance to other nNRTIs
Feb 13, 2003

Sustiva (efavirenz)-Induced Mutation in Subtype C HIV May Confer Multi-NNRTI Resistance

A mutation at codon 106 in HIV-1 clade C viruses that occurs after exposure to efavirenz appears to result in high-level resistance to other non-nucleotide reverse transcriptase inhibitors (NNRTIs), according to a report published in the January 3rd issue of AIDS.

Dr. Bluma Brenner, from McGill University AIDS Centre in Montreal, and colleagues genotyped 440 B and 84 non-B HIV-1 clinical isolates. The non-B isolates included 39 clade C variants.

In 94 of cases, the clade C viruses carried the natural GTG polymorphism at codon 106, which can allow the valine-to-methionine mutation to arise at this location under drug selection pressure. In contrast, the B isolates "overwhelmingly" expressed the GTA sequence at codon 106.

In tissue culture, the V106M mutation occurred when clade C viruses from treatment-nave patients were exposed to efavirenz, but not to nevirapine or delavirdine.

Once present, the codon 106 mutation was found to cause high-level resistance to all NNRTIs, the authors note. Testing with recombinant viruses containing the mutation confirmed this finding.

The V106M mutation "may be a signature mutation in clade C patients treated with efavirenz and may have the potential to confer high-level multi-NNRTI resistance," the researchers conclude. "Physicians should be aware of the...mutation and its potential impact on virological responsiveness," they add.


I know this may seem self-explanatory..but do you know how extensive and how many people this can/will affect? The reason I am asking is because Sustiva has been shown to be highly effective in all it's trial studies, and this seems to very much so spoil a lot of that.I've included a web link address that i got this from (another great website) And I wrote and asked you becasue I myself attended CU boulder years ago (off the subject)thanks Doctor Young.

Response from Dr. Young

Thanks for pointing out the research.

So far, this does not seem like a very common issue-- however, a different mutation at codon 103 is commonly found among persons with clade B HIV (the US, Western Europe flavor)- this mutation usually causes high level resistance to all NNRTIs.

Go Buffs. -BY

Restarting Treatment
Should I start treatment right now

  • 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