Phenytoin overdose complicated by prolonged intoxication and residual neurological deficits

This report describes a case of massive phenytoin deliberate self-poisoning, notable for delayed peak serum concentrations, multiple general complications, and permanent cerebellar injury. A 38-year-old 70 kg male patient presented to the ED after ingestion of at least 10 g of phenytoin 12-16 h earlier. Marked cerebellar dysfunction and persistent vomiting were observed, with an initial serum phenytoin concentration of 181 micromol/L. Initial conservative treatment (activated charcoal, whole bowel irrigation), and later attempts at charcoal haemoperfusion were unsuccessful. The serum phenytoin concentration peaked on day 15 (354 micromol/L). The patient developed seizures followed by a prolonged depression in conscious state requiring intubation. Multiple medical sequelae occurred and the patient was discharged to a rehabilitation facility 100 days after admission exhibiting signs consistent with permanent cerebellar dysfunction.