Safety of perioperative treatment with intravenous amantadine in patients with parkinson disease

OBJECTIVES: Surgery in patients with Parkinson disease is associated with a high rate of complications largely because of difficulties in maintaining the antiparkinsonian treatment regimen perioperatively. The aim of the study was to investigate the safety and efficacy of intravenous administration of amantadine on parkinsonian features during and after surgery. METHODS: The study group included 6 patients being treated for Parkinson disease who were referred for surgery at a tertiary medical center. After providing written informed consent, participants received intravenous amantadine sulfate 200 mg after induction of anesthesia and 24 hours later. The regular antiparkinsonian regimen was stopped immediately before surgery and restarted after surgery. Patients underwent a neurological evaluation with the Unified Parkinson Disease Rating Scale at 3 time points: preoperatively, 24 to 72 hours postoperatively, and 1 month postoperatively, and the scores were compared. RESULTS: The mean Unified Parkinson Disease Rating Scale score improved from 24.8 (SD, 10.8) at baseline to 21.3 (SD, 11.1) at 24 to 72 hours postoperatively (P = 0.04); the value at 1 month (in the 5 patients assessed) was 22.5 (SD, 15.5) (P = 0.27). No adverse effects of amantadine or postoperative complications were recorded. All patients were discharged home as planned. CONCLUSIONS: Amantadine improves the parkinsonian symptoms after surgery, which may be beneficial in preventing complications. It appears to have a high safety profile in this setting. Larger, randomized, and blinded studies are warranted to corroborate these preliminary results and evaluate long-term outcome.