The toxicity symptoms of olanzapine are known to include somnolence, mydriasis, blurred vision, respiratory depression, hypotension, extrapyramidal symptoms and anticholinergic effects. The overdosage effects in children are generally associated with more significant side effects.^A177059

The maximum registered dosage of olanzapine in clinical trials was of 300 mg and it was reported to present drowsiness and slurred speech. However, on post-marketing surveillance, a wide range of symptoms have been presented including agitation, dysarthria, tachycardia, extrapyramidal symptoms, and reduced consciousness. One case of overdosage-driven death was reported after ingestion of 450 mg of olanzapine. In the cases of acute overdosage, the establishment of adequate oxygenation and ventilation, gastric lavage and administration of activated charcoal with a laxative is recommended.^{FDA label}

In carcinogenesis studies, olanzapine was showed to present an increase in the incidence of liver hemangiomas and hemangiosarcomas as well as mammary gland adenomas, and adenocarcinomas. On fertility studies, there was solely found impairment in male mating performance and delays in ovulation. There is no evidence of mutagenic, genotoxic potential not adverse events on fertility.^{FDA label}