Catatonia-like events after valproic acid with risperidone and sertraline

A patient with schizoaffective disorder developed signs of catatonia while on a regimen of valproic acid, sertraline, and risperidone. The catatonic f eatures evolved for the first time after a single dose of valproate and wer e alleviated by lorazepam. The same catatonic signs recurred after a second dose of valproate and again remitted after lorazepam. Catatonia did not re cur subsequent to discontinuing valproate, and the patient had tolerated th e combination of valproate and risperidone in the past without developing c atatonia. Although the catatonia in this case initially appears to be parad oxical, the phenomenon is actually consistent with current models of catato nia. A unique drug interaction may account for this phenomenon. Possible ph armacokinetic and pharmacodynamic explanations are discussed, including the relation of catatonia to increased activity of the medial globus pallidus and current models of catatonia.