Frequent
Methamphetamine Use Is Associated with Primary NNRTI Resistance
Some
studies indicate that use of methamphetamine is associated
with higher rates of unprotected sex, which experts
fear could lead to a higher incidence of HIV infection. Methamphetamine use many
also impact HIV disease progression.
As
reported in the January 11, 2007 issue of AIDS, San Francisco researchers
assessed whether methamphetamine use is associated with an increased prevalence
of primary HIV drug resistance. Primary resistance refers to initial infection
with drug-resistant strains of HIV, as opposed to resistance that evolves over
time due to drug exposure.
The
study included 300 men who have sex with men (MSM)
enrolled in the Options Project -- a study of early HIV infection -- between 1996
and 2005. All the men experienced HIV antibody seroconversion within the prior
12 months. Participants completed structured interviews about their risk behavior
and underwent genotypic resistance testing
using the Bayer
TrueGene assay.
Results
•
13 individuals
reported antiretroviral use within 6 months of their exposure period, which may
have represented the use of postexposure
prophylaxis.
•
83 participants (28%) reported methamphetamine use during the previous 30 days.
•
12% reported weekly or more frequent methamphetamine use.
•
Among individuals
who reported frequent methamphetamine use, 34% were resistant to at least 1 drug
class, compared with 21% of infrequent users and 25% of non-users.
•
In a multivariate model controlling for multiple sex partners, race/ethnicity,
other illicit drug use, and previous use of antiretroviral drugs, frequent (weekly
or more often) methamphetamine use was associated with primary resistance to any
class of anti-HIV drugs [odds ratio (P = 0.06).
•
This remained
true after also adjusting for the year of study entry, participant age and education,
heavy alcohol use, and any protected vaginal or anal sex.
•
However, infrequent methamphetamine use (less than weekly) was not associated
with drug resistance in either model.
"Our
results, and such high prevalence rates of methamphetamine use among MSM [26%
in one survey], suggest that methamphetamine may be an important co-factor in
the transmission of NNRTI resistance in this population," the authors concluded.
They
proposed that, "this association may be caused by methamphetamine-associated
treatment interruptions among source partners," suggesting that HIV negative
methamphetamine users were likely to have unprotected sex with HIV positive users
who had already developed drug resistance due to suboptimal adherence.
"The
convergence of treatment interruptions and high-risk behavior could be responsible
for the high rates of drug resistance we report here," they wrote.
This
hypothesis is supported by the fact that suboptimal adherence is especially associated
with the emergence of resistance to NNRTIs compared with other classes of antiretroviral
drugs.
"These
results reinforce recent recommendations to conduct resistance testing before
starting antiretroviral therapy in individuals with recent HIV infection, and
suggest that such testing is especially important among frequent methamphetamine
users," the authors concluded. "Our analysis also supports the need
to develop effective treatment programs for methamphetamine users, not only to
reduce risk behaviors, but also to prevent the transmission of NNRTI resistance."
AIDS
Office, San Francisco Department of Public Health, San Francisco, CA; Positive
Health Program, San Francisco General Hospital, San Francisco, CA; Gladstone Institute
of Virology and Immunology, San Francisco, CA; Osher Center for Integrative Medicine,
University of California, San Francisco, CA.
02/02/07
Reference G
N Colfax, E Vittinghoff, R Grant, and others. Frequent methamphetamine use is
associated with primary non-nucleoside reverse transcriptase inhibitor resistance.
AIDS 21(2): 239-241. January 11, 2007.
Index
of All HIV and AIDS Articles by Topic ( A to Z)
Some
studies indicate that use of 
