Figure 1.

Dose-effect curves for remifentanil determined by thermal and mechanical nociceptive assays. (A) Hotplate test. The ED₅₀ was 16.0 mg/kg (n = 8); the doses were 2, 4, 8, 16, and 32 mg/kg. (B) Plantar test. The ED₅₀ was 35.7 mg/kg (n = 9); the doses were 8, 16, 32, and 64 mg/kg. (C) Randall-Selitto test. The ED₅₀ was 6.9 mg/kg (n = 11); the doses were 2, 4, 8, 16, and 32 mg/kg. The data are presented as percent maximal possible effect (%MPE) ± SEM.