First clinical experience with a new neuromuscular blocker pipecurium bromide

The clinical trial of the new non-depolarizing muscle relaxant 2 beta,16 beta-bis-(4'-dimethyl-1'-piperazino)-3 alpha,17 beta diacetoxy-5 alpha-androstane dibromide (pipecurium bromide, RGH-1106, Arduan) was performed on 80 patients who had to undergo medium and major size intraabdominal operation on the basis of chronic surgical indication. Four types of general anaesthetic methods were applied, neuroleptanalgesia, halothane, halothane-fentanyl combination and hydroxydione. The clinical applicability of pipecurium bromide was tried to establish the dose needed for complete muscle relaxation initially and repeatedly and the effect of antagonist drugs on the muscle relaxation. We investigated the duration of the first and repeated dose of the relaxant. Heart rate and arterial blood pressure were measured, mean arterial pressure and pulse pressure were calculated. In 10 patients of the halothane group the behaviour of some haemodynamic parameters was investigated. The changes of acid base parameters, blood gases, serum electrolytes and blood sugar were also observed. The administered doses were initially 3.88 mg/h, repeated doses 2.32 mg/h, this means 0.052 mg/kg body weight initially and 0.026 mg/kg body weight repeatedly The duration of effect after the first dose was 53 min, after the repeated doses 45 min. There were no direct effects on heart rate and arterial blood pressure. It did not affect myocardial contractility or work function, there was no remarkable changes in cardiac output. There were no direct metabolic changes due to pipecurium bromide. The relaxant has no histamine releasing effect. At the end of the anaesthesia the effect can be antagonized with neostigmine. During our observations there were no side effects or allergic reactions caused by pipecurium bromide.