Effect of preoperative oral amantadine on intraoperative anesthetic and analgesic requirements in female patients during abdominoplasty

Background
We hypothesized that NMDA antagonist, amantadine, may be beneficial in reducing the intraoperative anesthetic and analgesic requirements. The aim of this study to evaluate the effect of preoperative oral amantadine on induction doses of propofol, intraoperative anesthetic and analgesic requirements.
Methods
In a prospective, randomized, double-blinded controlled study 60 female patients ASA I or II aged 18–60 years old, planned for abdominoplasty surgery divided into two groups (30 patients each). Group A: received oral amantadine 200 mg on the evening before surgery and 200 mg 60 min prior to surgery. Group P (control group): the patients received placebo capsules. Propofol and isoflurane were titrated guided by BIS during induction and maintenance of anesthesia where the total dose of propofol and the time elapsed between injection of propofol to achieve BIS value 60 were recorded. Also, the inspired isoflurane concentrations required to maintain BIS between 40 and 60 and the total dose of fentanyl needed to maintain adequate analgesia were recorded.
Results
The induction dose of propofol and the time from propofol injection till BIS value reached 60, the total intraoperative fentanyl requirements and the inspired isoflurane concentration required to maintain BIS reading between 40 and 60 were statistically significant lower in amantadine group compared to placebo treated group. The two groups were similar regarding the occurrence of side effects.
Conclusion
Preoperative oral amantadine reduced the induction time, induction dose of propofol, intraoperative anesthetic and analgesic requirements compared to placebo without serious side effects in female patients during abdominoplasty.