I've been on methadone off and on for almost 10 years, I was on 180mgs at one point but am down at 120 right now. Me personally have tried all the potentiators and I just never got anything out of Cimetidine (Tagamet), I've tried taking it before I dose, after I dose, large doses, small doses. When I would take it before I dosed I swear it felt like it ruined or actually lowered my methadone response! The BEST methadone potentiators that I've found is WHITE grapefruit juice. I never dose without it. I buy the large 60oz. oceanspray brand at Wal-mart for $2.50 a jug. I dose and then exactly an hour after dosing, I time it to let the methadone get out of my stomach and absorbed so the acid in the GF juice dosent hinder the methadone then I drink exactly half the jug (30oz.). It's alot of liquid but I DO notice a difference. It doesn't increase the high or peak you feel all that much, but it does some, what it does do is makes it last noticeably longer so I'm not withdrawling by the next morning and makes my buzz during the day last longer. It's a CYP3A4 inhibitor. CYP3A4 is one of the main liver enzymes that breaks methadone and most other opiates down and metabolizes it into inactive waste. Supposedly Tagamet is supposed to do the same thing but I've just never had any luck with it. When I first started methadone once and was in horrible heroin withdrawal, you know how the clinics always start you at 30-40 Mgs and painstakingly slowly raise your dose. I even had the intake doctor tell me once to go home and drink some grapefruit juice cause it'll help the methadone work. I've researched it like crazy and you want WHITE grapefruit juice, it has more of the chemical in it that does the trick than regular GF juice and make sure it's 100% GF juice or GF juice from concentrate. You don't want to buy some grapefruit flavored water!
Another couple things that go great to potentiate methadone if you can get your hands on some are Any benzos, Klonopin is my favorite, or if you can't get a controlled substance script another drug that potentiators it great is Clonidine. Good luck my man. And remember, heroin withdrawal is relatively short lived depending on how much you were doing, how often, & for how long but the tolerance WILL eventually fall and you're methadone should start holding you. Try out the above, good luck and hang in there.
