Phenytoin is commonly prescribed for the prophylaxis of seizures in neurosurgical patients. A phenytoininduced
serious adverse effect of thrombocytopenia has been reported in the literature. The concurrent
use of dexamethasone, another commonly prescribed drug in neurosurgical patients, has been reported to
aggravate this adverse haematological effect. We present a report of phenytoin-induced thrombocytopenia
in a patient concurrently prescribed with dexamethasone, after an intracerebral haemorrhage secondary to
a rupture of an arteriovenous malformation. The thrombocytopenia was noted after two weeks of phenytoin
medication. Phenytoin was immediately withheld, and seven units of random donor platelets were transfused.
A gradual resolution of thrombocytopenia was observed within a week.