Abstract
Histamine releasing activity of chandonium iodide and d-tubocurarine was studied in guinea pig ileum (in vitro), guinea pig peritoneum (in vivo) and in human volunteers (in vivo) by intradermal testing at dilutions of 1:1,000 and 1:10,000 of the clinical dosage of drugs. d-tubocurarine revealed significant histamine releasing activity in in vivo animal experiments and high incidence of positive intradermal reaction, 53.5 per cent and 13.5 per cent, in human volunteers. Chandonium iodide neither showed histamine releasing activity in animals nor in man. In clinical terms, chandonium iodide appears to be a safe neuromuscular blocking agent.