Intentional chloroquine overdosage.

Twenty-six episodes of intentional chloroquine overdosage are documented. The over-all mortality rate of 19%, and 50% incidence of cardiac arrest for ingestion of 2.25 g or more of chloroquine base indicate the risk of overdosage. Life-threatening cardiac arrhythmias may be the first sign of overdosage. However, gastrointestinal and neurological symptoms generally precede this sign. Early recognition and attempts to decrease drug uptake are important as current therapy after absorption of the drug is inadequate.