Survivors of severe brain injuries may end up in a state of 'wakeful 
unresponsiveness' or in a minimally conscious state. Pharmacological treatments 
of patients with disorders of consciousness aim to improve arousal levels and 
recovery of consciousness. We here provide a systematic overview of the 
therapeutic effects of amantadine, apomorphine and zolpidem in patients 
recovering from coma. Evidence from clinical trials using these commonly 
prescribed pharmacological agents suggests positive changes of the patients' 
neurological status, leading sometimes to dramatic improvements. These findings 
are discussed in the context of current hypotheses of these agents' therapeutic 
mechanisms on cerebral function. In order to improve our understanding of the 
underlying pathophysiological mechanisms of these drugs, we suggest combining 
sensitive and specific behavioral tools with neuroimaging and 
electrophysiological measures in large randomized, double-blind, 
placebo-controlled experimental designs. We conclude that the pharmacokinetics 
and pharmacodynamics of amantadine, apomorphine and zolpidem need further 
exploration to determine which treatment would provide a better neurological 
outcome regarding the patient's etiology, diagnosis, time since injury and 
overall condition.