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.