[Change in skin reactivity in anaphylaxis to muscle relaxants and hypnotics after administration of anti H1, anti H2 and tritoqualine].

Inhibition of allergic skin reactivity was studied by the technique of thresholds in 35 patients presenting with an anaphylaxis to muscle relaxants. This method was useful to determine the anti-histamine or anti-anaphylactic effects of different substances. The best results were obtained with hydroxyzine. Associating it with an anti H2 drug (cimetidine or ranitidine) did not improve these results. Skin reactivity was never entirely abolished. This confirmed that no premedication could avoid the occurrence of an anaphylactic shock, or even reduce its magnitude. However, premedicating before general anaesthesia with anti H1 and anxiolytic drugs must be continued for all high risk patients: the prevention of non-specific histamine release appeared to be much more efficient than that of anaphylaxis.