A controlled trial of nevirapine plus zidovudine versus zidovudine alone in p24 antigenaemic HIV-infected patients

Objectives: Nevirapine is a non-nucleoside reverse transcriptase inhibitor of HIV-1 which exhibits synergy in vitro with zidovudine (ZDV and also is active against ZDV-resistant HIV. We evaluated the activity and safety of nevirapine in combination with ZDV in patients receiving long-term ZDV therapy. Methods: We conducted a randomized, open-label, controlled 28-week study of nevirapine (200 mg daily for 2 weeks followed by 200 mg twice daily for 26 weeks) and continued ZDV (500-600 mg daily) versus continued ZDV alone in 49 HIV-1 p24 antigenaemic patients with CD4+ lymphocyte counts < 500 x 10(6)/l and who had been treated with ZDV for at least 6 months. Results: Addition of nevirapine to ZDV resulted in a significant and rapid reduction in circulating RNA load (mean, 0.65), a mean CD4+ lymphocyte rise of 34 x 10(6)/l, a reduction in serum beta(2)-microglobulin and a median fall in immune complex dissociated p24 antigen levels of 69%. These changes remained statistically significant for 4, 4, 12 and at least 28 weeks, respectively. The principal adverse event due to nevirapine was a hypersensitivity reaction comprising rash with or without fever and mucositis in eight (32%) patients, which was dose-limiting in seven patients. Conclusion: Nevirapine exhibits significant although transient anti-HIV activity in ZDV-pretreated patients but its use is frequently associated with a hypersensitivity reaction.