Amantadine for traumatic brain injury: does it improve cognition and reduce agitation?

OBJECTIVE: To review the available literature pertaining to amantadine as therapy for improving cognition and reducing agitation following a non-penetrating traumatic brain injury (TBI). DATA SOURCES: Clinical literature was accessed through MEDLINE (from 1966 to February 2004) and bibliographic searches. Key search terms included 'amantadine', 'traumatic brain injury', 'cognition', and 'agitation'. DATA SYNTHESIS: Amantadine is primarily used for treatment and prophylaxis of influenza A. Its ability to improve mentation and motor function in patients with head injury remains questionable. An evaluation of five clinical trials, two case reports, and one case series is conducted focusing on the use of amantadine following TBI. Patients in clinical trials were assessed using a variety of neuropsychological tools aimed at, among other things, assessing cognition and agitation. Although individual patient results varied, the majority of patients studied showed improved neuropsychological test scores. Similar observations are noted in the case reports and case series. Improvement in cognition and reduced agitation seems to occur with post-injury amantadine therapy.
CONCLUSIONS: Amantadine is a reasonable option for improving cognition and reducing agitation following a TBI but confirmatory evidence of the efficacy the drug is necessary.