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Rapid Screening of HIV Reverse Transcriptase and Integrase Inhibitors
Published on: April 9, 2014
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Efavirenz Pharmacogenetics and Weight Gain Following Switch to Integrase Inhibitor-Containing Regimens
Michael A Leonard1, Zinhle Cindi2, Yuki Bradford3
1Vanderbilt University Medical Center, Nashville, Tennessee, USA.
Summary
Integrase strand transfer inhibitors (INSTIs) can cause weight gain in people with HIV. CYP2B6 genotype influences weight gain after switching to INSTIs, potentially due to efavirenz withdrawal effects.
Area of Science:
- Pharmacogenetics
- HIV/AIDS Treatment
- Metabolism
Background:
- Some individuals with HIV experience weight gain on integrase strand transfer inhibitors (INSTIs).
- The mechanisms and risk factors for INSTI-associated weight gain remain unclear.
Purpose of the Study:
- To investigate the pharmacogenetics of weight gain in HIV patients switching from efavirenz to INSTI-based regimens.
- To examine the association between CYP2B6 and UGT1A1 genotypes and weight gain.
Main Methods:
- Two cohorts were analyzed: an observational cohort switching from efavirenz to INSTIs and a clinical trials cohort on efavirenz.
- Weight gain at 48 weeks was assessed in relation to CYP2B6 and UGT1A1 genotypes.
Main Results:
- In the observational cohort, CYP2B6 slow metabolizers showed greater weight gain after switching to elvitegravir or raltegravir (P=.01).
- In the clinical trials cohort, CYP2B6 slow metabolizers had less weight gain on efavirenz with tenofovir disoproxil fumarate (P=.001).
- UGT1A1 genotype was not associated with weight gain in either cohort.
Conclusions:
- CYP2B6 genotype is linked to weight gain in HIV patients switching from efavirenz to INSTI therapy.
- This association may relate to the withdrawal of efavirenz's inhibitory effect on weight.
- The impact of concomitant nucleoside analogues on this relationship requires further investigation.
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