Olza-5 Overdosage

Symptoms: Acute: During premarketing trials, 67 cases of acute overdosage with olanzapine were identified. The highest reported ingestion was 300 mg. The only symptoms reported in this patient were drowsiness and slurred speech. Among overdose patients who were evaluated in hospitals, none showed changes in laboratory analysis or electrocardiograms (ECG), and vital signs were usually within normal limits.
Treatment: Multiple drug involvement should be considered. There is no specific antidote to olanzapine.
To Decrease Absorption: Gastric lavage, after intubation if patient is unconscious, and administration of activated charcoal with a laxative should be considered. Activated charcoal has been shown to reduce absorption of olanzapine, and may be of use since olanzapine does not reach peak plasma levels for approximately 6 hrs following ingestion. The risk of aspiration with induction of emesis may be increased by possible obtundation, seizures, or dystonic reaction of the head and neck.
Specific Treatment: Hypotension and circulatory collapse may be treated with IV fluids and/or sympathomimetic agents. Because of olanzapine-induced α-blockade, sympathomimetics with β-agonist activity eg, epinephrine and dopamine, may worsen hypotension and should not be used.
Monitoring: Continuous ECG monitoring should be employed to detect possible arrhythmias. Close medical supervision should continue until patient recovers.
Supportive Care: Airway should be established and maintained to ensure adequate oxygenation and ventilation. Patients in whom intentional overdose is confirmed or suspected should be referred for psychiatric consultation.
Note: Olanzapine is not removed by dialysis.