Dyskinesia, cardiac arrhythmia and partial seizure associated with paliperidone overdose: a case report

Paliperidone is a new atypical antipsychotic agent. There are few literature reports of paliperidone overdoses and we report a case of these. A 32-year-old man was admitted to Emergency Department for occurrence of opisthotonus, muscular spasms and rigidity. Twenty hours before, he had an ingestion of 168 mg of paliperidone. He had hypotension and tachycardia. The dystonic reaction completely resolved within a few minutes after diazepam. Nine hours after admission, he sudden showed a right hemisoma partial seizure. The peculiar interest of our case is that three different and rare symptoms occurred in successive times after overdose. Some symptoms occurred after several hours following overdose. Oral paliperidone is available as an osmotic release delivery system that results in a gradual rise in plasma concentrations. According to this limited experience in which delayed onset of toxicity has been observed, it may be prudent to recommend prolonged observation after overdose of paliperidone.