Emergency medical workers also sometimes use ketamine to sedate people who appear to be out of control, aggressive or a threat to themselves or others.
Drugs like ketamine and PCP engage similar receptors, which is why it's important to take dextromethorphan as directed, as high doses are notorious for causing hallucinatory effects.
Mr. Iwamasa was one of five people who the authorities in California said this week had been charged with a conspiracy to distribute ketamine, a powerful anesthetic, to Mr. Perry.