WARWICK — Anthony Perito, 39, says he was in elementary school when he started using drugs. “I was a big fan of Fred Flintstones chewables,” the multivitamin supplement for children, he said. “My friend kind of tricked me into it. He gave me an ecstasy tablet that was shaped like Fred Flintstone.” A street drug, ecstasy is a psychoactive substance that alters mood, increases energy, and can have hallucinogenic effects. In the neighborhood of Taunton, Massachusetts, where Perito grew up, it was but one of many illicit drugs that were easily available. “From there, I went to acid and marijuana,” Perito said. He began selling drugs, too, and as he grew older, he began using opioids, including Percocet, a drug that includes the painkiller oxycodone.