Ouestion about using Cimetidine (tagamet) as an opiate potentiator?

[oxyhydro]

SWIM recently learned that when using grapefruit juice as a potentiaor you should drink it at least 3 hours before taking any opiates to get the best results, does the same go for tagamet? SWIM hasent had a chance to test this yet but they do almost the same thing in the liver so SWIM is thinking you shoud also take tagamet at least 3 hours before any opiates. Can anyone that has tried this fill me in?

Also I'm not so good at posting in the right catagory so if this is the wrong catagory could you please tell me?

[chibi curmudgeon]

Cimetidine isn't as strong a 3A4 inhibitor as grapefruit juice, plus it'll inhibit codeine activation (though I'm guessing SWIY wasn't planning on using codeine.) The inhibition of codeine activation (via 2D6) will also prevent oxycodone metabolism, though.

Point is, grapefruit juice might be a better idea, and it's cheaper.

I'm basing this, btw, off Indiana University's P450 interaction table. Nice, but doesn't go into much detail.

[ninjaned]

swim has actually used this and compared to grapefruit juice(in his opinion) grapefruit was a lil bit better. but if this is easy for swiy to find then try it, and let all of us here at DF know how it worked for swiy.

[oxyhydro]

SWIM just experimented using both and WOW what a difference! SWIM took 400mgs cimetidine with a huge glass of half grapefruit juice and half tonic water (quite a refreshing beverage on its own). Two hours later, SWIM lowered his dose to 30mg oxycodone from his usual 45mg dose, dissolved it in water along with 50mg benadryl, filtered the fillers out, and filled a syringe to administer the oxy/benadryl solution rectally. The difference was great! SWIM only took 30mg but it felt just like SWIM took 45mg! SWIM would suggest only taking 2/3 of your normal dose when potentiating with grapefruit juice and cimetidine. SWIM knows SWIM also had benadryl and tonic water (quinine) that may have also helped potentiate but SWIM always do the same thing the only difference was SWIM took the cimetidine 2 hours before the oxy instead of a half hour.

CONCLUSION: Cimetidine takes about two hours to have its inhibiting effect on the liver, as does grapefruit juice.

I will try another experiment later in the week to confirm this by only using cimetidine and oxycodone, no other possible potentiators. If anyone else has done a similar experiment with the same or different results, please post! I'm looking to get the truth about this commonly debated topic.

[chibi curmudgeon]

Originally Posted by oxyhydro

SWIM knows SWIM also had benadryl and tonic water (quinine) that may have also helped potentiate

I posted a link to a CYP table; I highly recommend swiy look for answers there.