The inhibitory action of lidocaine in anaphylaxis

The action of lidocaine, a local anesthetic, was investigated during anaphylaxis in guinea pigs after passive sensitization in vitro of lung tissue and trachealis muscle. Pretreatment of the trachealis muscle with 8.54 mM lidocaine resulted in the total inhibition of anaphylactic isometric tension. Full reversal of anaphylactic-induced contractures was rapidly achieved with concentrations of 4.27 mM lidocaine. Release of histamine from both lung tissue and trachealis muscle was inhibited by 73 to 82 per cent, respectively, over concentration ranges of 2.13 to 8.54 mM lidocaine. A bimodal effect on sensitized tissues was noted, with lidocaine causing a slight release of histamine in the trachealis muscle of 1.6 per cent at a concentration of 8.54 mM. Lidocaine did not impair the initial passive sensitization process, nor did it appear to elute antibody once it was cell bound. The dual inhibitory effect on mast-cell release of mediators and on muscle contraction by lidocaine may be related in part to common processes involving the binding or flux of calcium.