Background: Application of knowledge of isomerism is currently becoming popular to obtain drugs with better pharmacodynamic profile and without major side effects. We aimed in our study to compare the effects of the cis-isomer of Atracurium with its parent molecule Atracurium for producing muscle relaxation. Methods: We enrolled 60 adult patients of ASA status I and II who needed skeletal muscle relaxation under general anaesthesia in a comparative double blind randomised study. Patients were randomly placed in group A and group B to receive either Atracurium(0.5 mg/kg) or Cisatracurium(0.2 mg/kg) respectively to provide neuromuscular blockade during a Propofol/N2O/O2/Isoflurane anaesthesia. Each patient was studied for onset and duration of action of the drug, laryngoscopic and intubating conditions, haemodynamic profile, reversibility and side effects. Results: Both the drugs produced jaw relaxation within three(3) minutes of administration and had intermediate duration of action. Intubating conditions were excellent in both the groups in majority of patients. Patients who received Cisatracurium maintained better haemodynamic profile though this difference was statistically insignificant. Effects of both the drugs were easily reversible by Neostigmine and none of the patients showed signs of Histamine release. Conclusion: Neuromuscular blocking effects of Cisatracurium are similar to Atracurium with less haemodynamic changes.
