HAART Regimens Changes Due to Drug Toxicities in HIV Positive People with Virological Suppression

Many prior studies have looked at switching various antiretroviral drug regimens due to virological failure or side effects, but few researchers have focused on maintenance of stable anti-HIV therapy over time.

The objective of the present study, published in the May 31, 2008 issue of AIDS, was to examine the rate of treatment change due to drug-related toxicities among patients who achieved full viral load suppression within 6 months after starting combination antiretroviral therapy and who never experienced virological failure.

The analysis included 508 HIV positive patients attending the Royal Free Hospital in London who started antiretroviral therapy in the 2000-2005 period and achieved viral suppression below 50 copies/mL within 6 months. The study covered 912 person-years of follow-up.

During follow-up (censored at the time of virological failure), participants were taking a regimen of lamivudine (3TC; Epivir) or emtricitabine (Emtriva) plus a second nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) plus either a protease inhibitor (PI) (usually ritonavir-boosted) or a non-nucleoside reverse transcriptase inhibitor (NNRTI).

Results

• Over 912 person-years of follow-up, there were 357 total treatment changes.

• 140 changes (50.2% of all changes with a known cause) were due to drug toxicities.

• Other reasons for changing therapy were patient choice (17.6%) and poor adherence (3.6%).

• The overall rate of treatment change was 39.1 per 100 person-years, and the rate of change due to toxicity was 15.4 per 100 person-years.

• The most common toxicities leading to changes were central nervous system symptoms (22.9%) and lipodystrophy (body fat changes; 19.4%).

• In a multivariable analysis, factors associated with a higher rate of treatment change due to toxicities included:

• Older age;

• Being on stavudine (d4T; Zerit) compared with zidovudine (AZT; Retrovir);

• Being on lopinavir/ritonavir (Kaletra) compared with efavirenz (Sustiva);

• Factors associated with a lower rate of treatment change were:

• Being on tenofovir (Viread) compared with zidovudine;

• Being on atazanavir (Reyataz) compared with efavirenz.

The study authors concluded, "In patients who have never experienced virological failure, the rate of treatment change due to toxicities is low, and certain regimens are associated with an even lower rate of change."

In addition, they noted, "If virological failure is avoided, some regimens are so far proving to be sufficiently stable to suggest that very long-term use is potentially feasible."

A similar study looking at the Swiss HIV Cohort found a higher rate of treatment change during the 2000-2005 period, but in that study as well, patients taking tenofovir were less likely to switch.

Royal Free and University College Medical School, UK.

6/13/08

Reference

RK Lodwick, CJ Smith, M Youle, and others. Stability of antiretroviral regimens in patients with viral suppression. AIDS 22(9): 1039-1046. May 31, 2008.

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