An Arizona man has died after ingesting chloroquine phosphate — believing it would protect him from becoming infected with the coronavirus. The man’s wife also ingested the substance and is under critical care. The toxic ingredient they consumed was not the medication form of chloroquine, used to treat malaria in humans. Instead, it was an ingredient listed on a parasite treatment for fish.The couple — both in their 60s and potentially at higher risk for complications of the virus — decided to mix a small amount of the substance with a liquid and drink it as a way to prevent the coronavirus. People who attempt to self-medicate risk serious side effects or death, and it’s why any messaging about chloroquine and the related hydroxychloroquine should emphasize that these drugs have not been approved to prevent or treat the new coronavirus.Notably, the malaria drug comes in tablet form, but the type the couple used was a toxic substance — not medication.