Tenofovir
(Viread) Is Better Tolerated than AZT (Retrovir) as Part of a Post-exposure Prophylaxis
Regimen By
Liz Highleyman
Post-exposure
prophylaxis (PEP) refers to use of antiretroviral
drugs within 72 hours after a known or suspected exposure to HIV in an attempt
to prevent the virus from taking hold in the body.
In the April 2008 Journal
of Acquired Immune Deficiency Syndromes, researchers at the Fenway Community
Health in Boston -- the largest center caring for HIV positive and high-risk men
who have sex with men (MSM) in New England - reported data from the clinic's
non-occupational PEP program, which started in 1997.
Initially
the program used antiretroviral regimens containing zidovudine (AZT;
Retrovir), but clinicians found that suboptimal adherence in completing the
recommended 28-day course of therapy resulted in some prophylaxis failures.
In
the current analysis, the authors assessed data from 2 Phase IV (post-marketing)
studies of non-occupational PEP using tenofovir (Viread)
combined with either lamivudine (3TC;
Epivir) or emtricitabine (Emtriva;
also coformulated with tenofovir
in the Truvada pill).
Between
May 2004 and March 2005, 44 individuals with high-risk sexual exposure were prescribed
tenofovir/lamivudine for non-occupational PEP, and between March 2005 and March
2006, 68 individuals with 72 high-risk exposures received tenofovir/emtricitabine.
These patients were compared with 122 historical control patients who had been
treated with 126 courses of zidovudine/lamivudine PEP between January 2000 and
May 2004.
 Results
•
72.0% of patients who took tenofovir/emtricitabine and
87.5% of those who took tenofovir/lamivudine completed their regimens as prescribed,
compared with 42.1% of those who took zidovudine/lamivudine (P < 0.0001).
•
Participants who took tenofovir-containing regimens were
more likely to report diarrhea or abdominal discomfort.
•
Patients who took zidovudine-containing regimens were
more likely to report nausea and vomiting, which was often severe enough to lead
to discontinuation.
Conclusions
"Tenofovir
DF-containing regimens for [non-occupational] PEP are generally well tolerated
with high completion rates," the study authors concluded.
"Tolerability
and adherence compared favorably to zidovudine-containing regimens used previously,"
they added. "Tenofovir DF-containing regimens should be considered for PEP
to enhance adherence and regimen completion."
3/28/08 Reference
K
Mayer, M Mimiaga, D Cohen, and others.Tenofovir DF Plus Lamivudine or Emtricitabine
for Nonoccupational Postexposure Prophylaxis (NPEP) in a Boston Community Health
Center. Journal of Acquired Immune Deficiency Syndromes 47(4): 494-499.
April 1, 2008. | 
