Cost analysis and safety comparison of Cisatracurium and Atracurium in patients undergoing general anesthesia. BACKGROUND: Non-depolarizing neuromuscular blocking agents (NMB) differ in pharmacokinetic and pharmacodynamic parameters. An anesthesiologist according to these similarities and differences is able to choose the least costly one if the same safety profile and same clinical benefit achieved with the different alternatives. AIM: The main objective of this study is to evaluate the economic and adverse drug reactions prevalence and differences between cisatracurium and atracurium the two non-depolarizing NMB drugs, which are widely used in adult patients undergoing surgery with general anesthesia in a teaching Hospital in Iran. MATERIALS AND METHODS: A cost analysis and adverse drug reactions (ADR) monitoring were performed. Only direct costs were considered and data were collected through a prospective randomized study. Regardless of the type of surgery, 100 patients were randomly divided into two equal groups to receive either cisatracurium or atracurium by anesthesiologists. ADRs prevalence and cost differences between patients receiving one of the two non-depolarizing NMB agents were evaluated by independent sample t-test and Chi-square test respectively. RESULTS: No significant difference was observed between the two groups of patients in demographic data. There was no statistical difference in the ADR prevalence in both groups. The numbers of ADR within atracurium group was higher than cisatracurium group, but this distinction was not statistically significant (p > 0.05). It was significant difference in cost between the two neuromuscular blocking drugs (p < 0.05). CONCLUSIONS: According to our study it seems that atracurium and cisatracurium had similar safety profile and atracurium had a cost benefit relative to cisatracurium in initial loading doses. In patients with instability in hemodynamic parameters the cisatracurium was the appropriate choice.