An Arizona man is dead and his wife is gravely ill after consuming a substance President Trump hyped up as a cure for COVID-19. The substance, chloroquine phosphate, is notably used to clean fish tanks and is also present in malaria medication.

While the drug has been theorized by some to be a viable treatment for coronavirus, it has yet to be suitably tested for that purpose. Despite concerns and objections from medical experts, Trump claimed that the medication had been approved by the FDA for treating the virus and repeatedly touted it as a cure.

The unnamed couple, who were in their 60s, found the substance on a shelf in their Phoenix home and decided to ingest it after hearing Trump’s assertions.

“I saw it sitting on the back shelf and thought, 'Hey, isn't that the stuff they're talking about on TV,'” the woman said to NBC News. “We were afraid of getting sick.”

Within half an hour, the couple fell violently ill and reported feeling dizzy and overheated. The wife began to vomit and her husband “developed respiratory problems.”

They were taken to the hospital after the wife called 911 where her husband died after staff were unable to resuscitate him. The woman is now said to be in critical condition.

“Given the uncertainty around COVID-19, we understand that people are trying to find new ways to prevent or treat this virus, but self-medicating is not the way to do so,” Dr. Daniel Brooks, the Poison and Drug Information Center medical director for Arizona’s Banner Health, said in a statement. “The last thing that we want right now is to inundate our emergency departments with patients who believe they found a vague and risky solution that could potentially jeopardize their health.”

While chloroquine phosphate is obtainable with a prescription, Banner has urged medical professionals from prescribing it to non-hospitalized patients.