Valproic acid and hyperammonemia.(Drug-Drug Interactions)

The antiepileptic agent valproic acid is increasingly used for management of psychiatric symptoms in patients with mania. The following case described an elderly woman developing hyperammonemia and thrombocytopenia.

Clinical case (1)

A seventy-six years old woman was diagnosed to have a generalized tonic-clonic seizure and was treated with phenytoin (Dilantin) and carbamazepine (Tegretol). Both antiepileptic agents were discontinued due to occurrence of speech problem and generalized rash, respectively. She was then started on sodium divalproex (Depakote) 750 mg three times daily ten days prior to her emergency room visit. The patient's other medical history included hypertension, angina, and myocardial infarction and she took several additional medications, including amlodipine …