Failure of cetirizine to prevent nevirapine-associated rash: a double-blind placebo-controlled trial for the GESIDA 26/01 Study.

Objectives: Rash is the most frequent adverse event associated with nevirapine. The use of antihistamines remains unclear in this setting. A double-blind placebo-controlled study was performed to evaluate the efficacy of cetirizine in the prevention of nevirapine rash.
Methods: A multicenter, randomized, double-blind, placebo-controlled clinical trial with cetirizine (10 mg/d x 30 days) was conducted. Inclusion criteria were HIV-1 infection and nevirapine therapy started with any CD4 cell count or plasma viral load and without simultaneous use of abacavir, cotrimoxazole, or rifampin. Clinical follow-up was performed at 15, 30, and 90 days.
Results: Two hundred seventeen evaluable patients were enrolled (107 patients receiving cetirizine and 110 patients receiving placebo), 32.3% of whom were women. The median baseline CD4 cell count and plasma viral load were 341 cells/mm and 11,000 copies/mL, respectively. Overall, 29 rashes (13.4%) were detected: 16 (15.0%) in the cetirizine group and 13 (11.8%) in the placebo group (odds ratio [OR] = 1.31, 95% confidence interval [CI]: 0.60-2.88; P = 0.50). The incidence of moderate to severe rashes leading to nevirapine withdrawal was 10.3% (11 of 107 patients) in the cetirizine group and 7.3% (8 of 110 patients) in the placebo group (OR = 1.46, 95% CI: 0.52-4.18; P = 0.43). Adverse events leading to withdrawal of therapy appeared in 14 patients (13.1%) from the cetirizine group and 10 (9.1%) from the placebo group (P = 0.34).
Conclusion: Cetirizine does not prevent the incidence or affect the severity of nevirapine-associated rash.