Chloroquine Seizures

Four cases of seizures were associated with therapeutic doses of chloroquine phosphate. This is, to our knowledge, the first specific report of this side effect in the literature. Other serious side effects have been noted, especially those involving the central and peripheral nervous systems. It is possible that such seizures are more common than has been previously noted, and they may be associated with an idiosyncratic reaction to the drug. All four cases had heralding signs of toxicity to which an alert physician must pay attention. It is concluded that chloroquine remains the drug of choice for such diseases as malaria and amebic hepatitis, but there is a narrow margin between a therapeutic and toxic dose and its use should be accompanied by the awareness of possible serious side effects on the central nervous system.