The Efficacy of Stavudine, Lamivudine and Nevirapine Combination Therapy

A favorable regimen for people infected with HIV/AIDS is one that provides optimal efficacy, durability of antiretroviral activity, tolerability, and has low adverse effects and drug-drug interactions.

The combination of the non-nucleoside reverse transcriptase inhibitor nevirapine (NVP; Viramune), and two nucleoside reverse transcriptase inhibitors, stavudine (d4T; Zerit) and lamivudine (3TC; Epivir), is widely used as first-line therapy, especially in low-resource countries.

Analysis of the efficacy, durability and tolerability of the regimen is thus important to clinicians, consumers and policy-makers living in both rich and poor countries.

The objective of the current study was to examine the efficacy of the stavudine, lamivudine and nevirapine regimen for the treatment of HIV infection and AIDS in adults.

The study authors used search strategy developed specifically by the Cochrane HIV/AIDS Review Group to identify HIV/AIDS randomized controlled trials, and searched the following electronic databases: MEDLINE (searched July 2004); Embase (searched October 2004); and CENTRAL (July 2004).

This search was supplemented with a search of AIDSearch (April 2005) to identify relevant conference abstracts, as well as searching reference lists of all eligible articles. The search was not limited by language or publication status.

The primary selection criteria were randomised controlled trials of the stavudine, lamivudine and nevirapine regimen, compared with any other regimens for treating HIV/AIDS, in antiretroviral treatment-naive or antiretroviral treatment-experienced adults.

Two reviewers independently assessed the methodological quality of the trials and extracted data.

Resutls:

·         The search resulted in 1,148 records, of which two studies described trials that met the inclusion criteria.

·         One trial was a small single-centre Australian trial of 70 antiretroviral-naive participants, while the other trial was a large, multicentre trial, conducted in 14 countries, of 1,216 antiretroviral-naive participants.

·         In both trials over 60% of participants were male.

·         As the therapeutic combinations compared in both trials were not identical, it was not possible to conduct a meta-analysis to increase the power of the results.

·         The main findings, therefore, are from the much larger trial, which was of a high quality.

·         This trial found that there was no statistically significant difference in the efficacy (measured by treatment failure) between nevirapine and efavirenz (EFZ), when used in combination with 3TC and d4T.

·         There was no statistically significant difference between once daily or twice-daily dosing of NVP, when used in combination with 3TC and d4T.

·         It also showed that, compared with NVP plus EFZ, 3TC and d4T, a once-daily dosing of NVP, in combination with 3TC and d4T, performs better in averting treatment failure than does twice-daily dosing of NVP with 3TC and d4T.

·         Frequency of toxicity was higher in participants receiving NVP, compared with EFZ.

Based on these findings, the authors conclude, “The combination of nevirapine, 3TC and d4T is as efficacious as a combination of efavirenz, 3TC and d4T.”

“Once-daily NVP with twice-daily 3TC and d4T is as efficacious as twice-daily NVP, 3TC and d4T. However, toxicity may be increased in the once-daily NVP regime.”

“Additional trials of sufficient duration are required to provide better evidence for the use of this combination as a first line therapy. Ideally, trials should use standardised assessment measures especially with respect to measuring viral load, so that results can be compared and combined in meta-analyses.”

04/25/06

Reference
N Siegfried, P Van Deventer, F Mahomed, and G Rutherford. Stavudine, lamivudine and nevirapine combination therapy for treatment of HIV infection and AIDS in adults. The Cochrane Database of Systematic Reviews (online) April 19, 2006(2):CD004535.