July 14, 2003
The choice between early initiation of antiretroviral therapy and avoidance of acute and chronic toxicities from these medicines is difficult and controversial. Investigators, clinicians and especially persons living with HIV are interested in antiretroviral therapy regimens that, while simple and non-toxic, are still capable of maintaining excellent, long-term control of viral replication.
Clinicians are becoming more and more comfortable with changing the antiretroviral regimens of patients who have stable suppression of HIV viral load to avoid or reduce toxicities and side effects and improve convenience and quality of life. This study was undertaken to determine if changing patients from more complex regimens to one of two simpler regimens (Trizivir [AZT + 3TC + ABV] -- one pill twice daily or Combivir [3TC + AZT]/nevirapine [NFV, Viramune] -- two pills twice daily) would improve quality of life, adherence and patient satisfaction.
The authors did not provide a breakdown of the participants' baseline regimens (probably protease-inhibitor based), nor did they provide the actual number of participants enrolled. They assessed the patient's quality of life by the MOS-HIV, the standard instrument used for this purpose. They also evaluated self-reported adherence, perceived effort to take medication and participant satisfaction with the number of pills, number of doses and dosing schedule. The results of participant satisfaction with the simplified regimens were not surprising: they felt more able to take the medication as prescribed; they were pleased with the lower number of pills, lower number of doses and the more convenient dosing schedule. Consequently, the participant's perceived effort to take the medication was reduced from baseline with both of the simplified regimens. The self-reported adherence was high in both groups. Interestingly, there was not a statistically significant increase in quality of life. The reasons for this were not discussed. The MOS-HIV may not be particularly sensitive to these general satisfaction issues, or the study may not have had a large enough sample size to find a significant difference even though one exists. No significant differences in any of the measures were found between the Trizivir and Combivir/nevirapine arms.
Other studies have reported on the virologic efficacy of similar switches. In general, they have found that switching from a protease inhibitor-based regimen to Trizivir is safe unless there is previous experience (and resistance) to single- or dual-NRTI regimens. Good results have also been found with switches from protease inhibitors to NNRTIs (efavirenz [EFV, Sustiva] or nevirapine). However, ACTG 5095 demonstrated that Trizivir was inferior to efavirenz-based therapies (efavirenz/Combivir or efavirenz/Trizivir). By extension, switching to Trizivir may lead to increased virologic failure compared to switching to an NNRTI-based therapy. The major reason clinicians and people living with HIV use Trizivir alone is for convenience and tolerability. This study suggests that the convenience and tolerability of Combivir/nevirapine is similar to that of Trizivir. Until there are more large, randomized, controlled trials of simplifying PI-based regimens with either Trizivir or two NRTIs plus an NNRTI, the safest option is to try an NNRTI-based regimen first, and use Trizivir only in patients who are intolerant to NNRTIs. Please note that these comments only apply to those patients who are virologically suppressed on a first antiretroviral regimen.
|Please note: Knowledge about HIV changes rapidly. Note the date of this summary's publication, and before treating patients or employing any therapies described in these materials, verify all information independently. If you are a patient, please consult a doctor or other medical professional before acting on any of the information presented in this summary. For a complete listing of our most recent conference coverage, click here.|