J Neuropsychiatry Clin Neurosci 1994; 6:250-256
Copyright © 1994 by American Neuropsychiatric Association
Clozapine-induced seizures and EEG changes
J Welch, T Manschreck and D Redmond
New Hampshire Hospital, Division of Neurology, Dartmouth Medical School, Concord 03301.
Clozapine, an atypical antipsychotic drug, is widely used in refractory
schizophrenia. At New Hampshire Hospital, 7 of the first 35 patients
treated (20%) had convulsions. Patterns were tonic-clonic (5), complex
partial (2), and myoclonic (3). Seizures were dose-related and may be
anticholinergic in etiology. EEG changes are frequent with clozapine,
particularly as dosage is increased. Twenty-six of 35 patients (74%) had
EEG abnormalities at some time during clozapine treatment. EEG is a
sensitive means of detecting clinical toxicity. When EEG abnormalities
(slowing, dysrhythmia, or paroxysmal discharges) are detected, immediately
lowering the dose by at least 25-50 mg per day and adjusting weekly until
EEG returns to baseline can reduce the incidence of seizures.
