order of 0.02-0.5 mg/l) saw its widespread use delayed until after the Second World War. Indeed, toxic symptoms have been re- ported with as little as 0.5 - 1.0 mg/l, and levels of >3.0 mg /l are often fatal.
Concern over the drug’s toxic properties led to the synthesis of a less toxic analog, hydroxychloroquine, in the 1950s. Estimated to be ~2x less toxic than chloroquine, this drug (marketed as Plaque- nil) continues to be used as an anti-malaria; as well as in the treat- ment of auto-immune diseases.
The toxicity of chloroquine is not well understood. The drug af- fects the movement of sodium and potassium through the cell walls. The resultant change in serum potassium can bring about cardiac arrest. This is not a peaceful death and, therefore, supple- mentary drugs are needed.
Packaging & Availability
Chloroquine is usually marketed as a salt (usually the phosphate form)‘chloroquine phosphate 250mg’ and comes in blister pack- ets of 20 tablets. Brand names include ‘Avloclor’. Much of the