In quinine and chloroquine poisoning, severe cardiovascular toxicity results from their Na + -channel blocking effects with hypotension, shock, dysrhythmias and cardiac arrest. Other features include coma, convulsions and, in quinine poisoning, oculotoxicity. Severity of symptoms is closely related to the dose ingested and plasma/serum concentration. In chloroquine poisoning, hypokalaemia is closely related to severity. Stabilization of the patient and treatment of cardiovascular disturbances are the priorities and include artificial ventilation and catecholamines for shock, and hypertonic sodium salts for intraventricular block. Diazepam is indicated for convulsions. Correction of hypokalaemia is controversial and potassium should be given very cautiously. In quinine poisoning, vasodilators and stellate ganglion block for retinal arteriolar vasoconstriction have not been shown to be effective. Gut decontamination (gastric lavage, activated charcoal) should be considered only less than one hour post-ingestion and only after stabilization of the patient. Extracorporeal elimination techniques are ineffective.