Allopurinol for refractory aggression and self-inflicted behaviour.

The impairment of the purinergic system, characterized by reduced adenosinergic activity, has been implicated in the neurobiology of aggressive behaviour. Since there are no direct adenosine agonists available for human use, inhibition of purine degradation by allopurinol was conceived as a possible strategy. We report two cases of adults with refractory aggressive behaviour due to a neurological condition (one mainly with self-inflicted behaviour) with dramatic response to therapy with allopurinol, 300 mg/day p.o. These preliminary results reinforce the involvement of the purinergic system in the neurobiology of aggression, warranting further testing of allopurinol as a new treatment for aggressive and self-inflicted behaviours.