Fig. 4. In ImmunoCAP inhibition assays, preincubation of sera with five neuromuscular blocking agents (rocuronium, vecuronium, atracurium, cisatracurium, suxamethonium) and morphine demonstrated a clear dose-dependent inhibition of immunoglobulin E (IgE) to rocuronium (n = 4 , closed circles ) and IgE to morphine (n = 3 , open circles ). There was no inhibition of IgE to latex.