[The histaminic and anaphylactic risks of atracurium]

The histamine releasing potential of atracurium was assessed by testing skin reactivity in ten patients who had previously suffered from a preanaesthetic anaphylactoid accident, but in whom the diagnosis of anaphylaxis had not been confirmed. Atracurium was injected intradermally in increasing concentrations so as to determine the reactivity level, comparing it in the same patient with that due to d-tubocurarine and alcuronium given in the same way. Skin tests with histamine and 48/80 were also carried out at the same time. When a positive reaction was obtained with atracurium, the injection was repeated 4 h after, the patient having taken 50 mg hydroxyzine p.o. The results showed that the skin reactivity level with d-tubocurarine was obtained with 1 in 100 dilution and with atracurium 1 in 10, with nine patients out of ten reacting positively. Alcuronium is the least histamine releasing drug, as it gave rise to a positive reaction in only two patients at a dilution of 1 in 10. Histamine release due to atracurium was greatly reduced by giving hydroxyzine. The allergizing potential was also studied in six other patients who had a tone anaphylaxis to a muscle relaxant and in whom crossed anaphylaxis was being tested for. All the commercial muscle relaxants together with atracurium were tested, even though none of the patients had ever received this last. Anaphylaxis was confirmed when the intradermal reaction was positive with a dilution of 1 in 1,000 and beyond. These tests showed that five patients out of the six had a crossed anaphylaxis, and one of these five was sensitive to all four muscle relaxants (atracurium included).(ABSTRACT TRUNCATED AT 250 WORDS)