Primary objective: To evaluate the association between amantadine and recovery of consciousness from prolonged traumatic coma.
Research design: A retrospective cohort study.
Methods: Subjects included 123 adults with severe traumatic brain injury (TBI) admitted over a 10-year period who remained in coma despite becoming medically stable.
Experimental interventions: Cases received 100-200 mg of amantadine twice daily.
Main outcomes and results: 46.4% (13/28) of cases emerged from coma compared to 37.9% (36/95) of controls (p = 0.42). Somatosensory evoked potential (SSEP) was the only significant predictor of emergence from coma (p = 0.02), while SSEP, age and Glasgow Coma Score (GCS) significantly predicted time to emerge from coma (p < 0.05).
Conclusions: Although the study and its design do not support the view that amantadine has an effect on recovery of consciousness; it remains safe, inexpensive and has few side effects. The lack of treatment alternatives and anecdotal support for its use may warrant further study. Prospective controlled trials would yield more definitive results.