St George of England, might that drug have been ketamine? On the street it is known as "Special K" or "horse tranks."
According to wikipedia, ketamine is a drug used in human and veterinary medicine, primarily for the induction and maintenance of general anesthesia. Ketamine has a wide range of effects in humans, including analgesia, anesthesia, hallucinations, elevated blood pressure, and bronchodilation. Like other drugs of its class, such as tiletamine and phencyclidine (PCP), ketamine induces a state referred to as "dissociative anesthesia" and is used as a recreational drug. Ketamine can be effective in treating depression in patients with depression and bipolar disorder who have not responded to antidepressants. It produces a rapid antidepressant effect, acting within two hours as opposed to the several weeks taken by typical antidepressants to work. Patients have reported vivid hallucinations, "going into other worlds" or "seeing God" while anesthetized, and these unwanted psychological side effects have reduced the use of ketamine in human medicine."
I had a cat that had developed an abcessed wound as a result of a feline territorial dispute, so we took him to the veterinarian for treatment. In the vet's words, this was a cat that "escallated easily" - he was fine with my wife and I but he didn't trust strangers, and the vet was a stranger... so the vet felt justified in giving the cat ketamine to anesthetize him, making the wound treatment easier for both of them. The next morning I picked the cat up and he was just waking fron his deep sleep; in fact he had not yet regained control of his hind legs - when we got home he dragged himself around using just his forelegs, and he seemed concerned that he couldn't use his hind legs, which probably made him feel vulnerable, creating an anxiety-loop in his cat mind.
(Reminds me of a line from Monty Python, "So I takes me cat out for a scrape 'round the block...")
But this wasn't funny, it was clear to me that my little buddy was hallucinating, and he was TERRIFIED by whatever it was he was seeing, amplified by his anxiety. He retreated to the security of his cat-carrier and spent most of the remainder of the day in there. When his system finally purged itself of the ketamine, he returned to being his old lovable, rascally cat-self, and he never spoke to me of his experience. I, for my part, called the vet and requested that a note be added to his medical file stating that he should never be given ketamine again.
Months later he was killed by a car; I still miss him.
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