Somnolence clozapine

A 20-year-old woman presented 6 hours after taking clozapine 3500 mg (242). She had unexpectedly prolonged tachycardia and somnolence, and recovered only after the serum clozapine concentration began to fall after a 4-day plateau. 

Data from short-term clinical trials (6 weeks) suggest that quetiapine may be useful for the management of psychotic disorders in patients who do not tolerate the adverse effects of the typical antipsychotic drugs or clozapine (3). The most common adverse effects of quetiapine were dizziness, hypotension, somnolence, and weight gain. Raised hepatic enzymes have also been reported. In addition, two patients with idiopathic Parkinson s disease and psychosis were treated with quetiapine for 52 weeks (4). Psychotic symptoms were successfully controlled without worsening of motor disability. 

The efficacy of clozapine has been described in 60 patients with levodopa-induced neuropsychiatric syndromes (32 assigned to the active drug and 28 to placebo) (72). The mean age was 72 years, the mean duration of disease was 12 years (Hoehn and Yahr stage 3.2), and the mean levodopa dosage was 774 mg/day. At a dose of up to 50 mg/day, clozapine significantly improved psychotic features, with minimal effects on parkinsonian symptoms. Clozapine caused somnolence but was otherwise well tolerated. 

In a 4-week, randomised, open-label comparison of ziprasidone and clozapine in the treatment of psychotic symptoms in Parkinson s disease, the most common initial adverse effect was somnolence [47 ]. There was no difference in movement disorder scales between the two antipsychotics. 

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