Valpros Pedia Overdosage

There have been reports of accidental and deliberate valproate overdosage. Signs and symptoms of overdosage include somnolence, heart block or deep coma.
At plasma concentrations of up to 5 or 6 times the maximum therapeutic levels, there are unlikely to be any symptoms other than nausea, vomiting and dizziness. Signs of acute massive overdose (with plasma concentrations 10 to 20 times the maximum therapeutic levels) usually include CNS depression or coma, with muscular hypotonia, hyporeflexia, miosis, impaired respiratory function and metabolic acidosis. Symptoms may however be variable and seizures have been reported in the presence of very high plasma levels. There have also been cases of intracranial hypertension related to cerebral edema. Deaths have occurred after massive overdose.
Hemodialysis or tandem hemodialysis with hemoperfusion have been used successfully. As valproic acid is absorbed very rapidly, gastric lavage may be of limited value. Management of overdose should consist of general supportive therapy, particularly maintenance of adequate urinary output.
Naloxone has been reported to reverse the CNS depressant effects of valproate overdosage. However, naloxone should be used with caution since it could also theoretically reverse the anticonvulsant effects of valproate.