Biphasic and long-lasting effect of ceruletide on tardive dyskinesia

A 55-year-old schizophrenic inpatient with buccolingual dyskinesia was treated with a single dose of ceruletide 0.8 micrograms/kg IM. Time-course effects of the drug were then followed for up to 6 weeks after injection. To assess changes in severity of bucco-lingual dyskinesia objectively, electromyogram (EMG) and microvibration (MV) were recorded. Simultaneously, bucco-lingual dyskinesias were also evaluated by using a five-point rating scale. Before injection of ceruletide, severity of dyskinesia was "moderate" and 3-4 Hz of dyskinetic oral movements were dominant. "Extremely severe" and repetitious gross oral movements (around 1 Hz) were observed within a few minutes after injection and continued for up to 1 h. Thereafter, oral movements tended to decrease, and they disappeared completely 3 weeks after injection. This biphasic and long-lasting effect of ceruletide on tardive dyskinesia might contribute to further understanding of the physio-pathophysiological role of cholecystokinin-like peptides in the brain, and provide a basis for practical treatment of tardive dyskinesia.