Objective: To evaluate the relationship of gabapentin therapy with choreoathetotic movements in mentally retarded patients treated with intractable epilepsy.
Design: Case reports of 2 institutionalized patients who developed choreoathetosis temporally related to adjunctive therapy with gabapentin at dosages of 1200 to 1800 mg/d.
Results: Both patients experienced resolution of abnormal movements on discontinuation of the therapy. One patient developed recurrent choreiform movements after drug rechallenge.
Conclusion: We suggest that, in patients with mental retardation and epilepsy, involuntary movements may either occur as reversible side effects of gabapentin therapy or result from a previously undescribed adverse drug interaction with other antiepileptic agents.