Clinical neuromuscular pharmacology of AH 8165 D, an azobis-arylimidazo-pyridinium-compound.

The neuromuscular blocking properties of AH 8165 D (1,1'azobis-(3-methyl-2-phenyl-1H-imidazo-1,2a-pyridinium)dibromide) were quantitatively studied in 50 patients, undergoing extra-abdominal surgery and anaesthetized with barbiturates, nitrous oxide, fentanyl and droperidol, by means of mechanograms of the hand muscles obtained by ulnar nerve stimulation. AH 8165 D is a rapid-acting nondepolarizing agent (full effect within 1--2 min) providing good intubation conditions similar to those obtained with suxamethonium. AH 8165 D may be considered to be indicated for emergency intubation in patients with full stomach when the risk of regurgitation is high. The duration of action of clinically useful doses (0.4-0.8 mg/kg body weight) is shorter than that of equi-effective doses of other nondepolarizing muscle relaxants. Repeated doses show a cumulative effect. The neuromuscular blockade can easily be reversed by an anticholinesterase drug. AH 8165 D-induced muscle relaxation is always accompanied by a dose-dependent tachycardia limiting the clinical usefulness of this new drug.