Effect of amantadine on the sleep–wake cycle of an inpatient with brain injury

Abstract

Background: A previous study suggested that the routine use of drugs intended to improve attention and arousal, such as methylphenidate, tend to have a variable but not significant effect on sleep–wake cycles. As amantadine is a frequently employed drug in brain injury rehabilitation, with known effects on fatigue and motor processing speed, this study examined the effect of amantadine on the sleep–wake behaviour of patients with brain injury undergoing rehabilitation.Method: This was a naturalistic observation using an observationally defined sleep–wake distribution for a total of 43 subjects with brain injury. Identified patients were observed for a full 24 hours a day 2 weeks before and 2 weeks after starting amantadine. Some of these patients (n = 12) had been administered amantadine on clinical grounds and, for this paper, served as the experimental group, while the drug naïve (n = 31) served as a control. Three outcome measures were operationalized: hours of sleep in 24 hours, hours of sleep during daytime and hours of sleep during night-time.Result: The average number of hours of sleep during a 24-hour period was not significantly different for the two cohorts. Similarly hours of sleep during daytime and hours of sleep during night-time were on average the same for the two groups. The data suggest that amantadine has no direct bearing on sleep/wake cycles using these parameters.Conclusion: This study fails to demonstrate that the use of amantadine on an inpatient brain injury population will affect sleep/wake quantity.