http://www.raintree-health.co.uk/cgi-bin/getpage.pl?/plants/quinine.html (http://www.raintree-health.co.uk/cgi-bin/getpage.pl?/plants/quinine.html)
http://adhpage.tripod.com/potentiators.htm (http://adhpage.tripod.com/potentiators.htm)
C. Boosting Opiates with Cytochrome P450 Inhibitors And Other Metabolism Issues
1. A dose of Tagamet an hour before a hydrocodone/oxycodone session will make the drug last longer and have a better effect. Antacids should be taken at least 45 minutes after the Tagamet otherwise absorption of the Tagamet will be impaired. Grapefruit juice also has the same type of impact on liver enzymes; use a Maalox chaser to neutralise any systemic acidification effect from the grapefruit juice. Tagamet should not be taken with codeine because it impairs the metabolism into morphine necessary for it to have any real effect.
2. Quinine and quinidine accentuate the buzz of opiates but only directly help with codeine metabolism by boosting the amount changed into morphine. Tagamet and grapefruit juice will weaken codeine substantially. The prescription antihistamine promethazine (Phenergan) helps out codeine even more, and is found with codeine in the Schedule V cough syrup Phenergan VC With Codeine. Quinine will tend to have its effect without impairing hydrocodone but does seem to burn off the buzz more quickly and may flatten the dose-to-response curve.
3. With all this liver magic going on and the acetaminophen content of a number of the drugs in question, the concurrent use of any alcohol at all with any of these mixtures should be thoroughly researched ahead of time. For example, washing down 5 Percocets with a vodka gimlet is not a good idea even if you have a massive tolerance to the narcotic. Also in many people moderate to large amounts of alcohol can change the subjective nature of the high for the worse and bring on sleep before the user intends. Anything more than 20 ml pure alcohol equivalent is likely to create trouble.
and here:
http://www.erowid.org/pharms/codeine/codeine_faq.shtml (http://www.erowid.org/pharms/codeine/codeine_faq.shtml)
n order to take full advantage of codeine, it is helpful to be familiar with some relevant pharmacology:
*CYP2D6
The body converts codeine into morphine (~10%) by using the so called P450 cytochrome pathway, especially cytochrome 2d6 (cyp2d6). Unfortunately, cyp2d6 is missing in about 7% of the white population, and its manifestation is quite variable in the rest. Individuals who inherited a cyp2d6 deficiency will get many of the adverse effects associated with codeine but little euphoria. If codeine just doesn't work for you, this may be why.
Some drugs also interfere with cyp2d6. Prime among these are the SSRIs, with the exception of Zoloft (if I remember correctly). The most potent inhibitor is paroxetine (paxil), followed by fluoxetine (prozac). If you are taking an SSRI, you will probably experience a markedly decreased euphoria when using codeine. (Paxil has a half life of only 24hrs, so not taking it for a few days will do miracles; the half life of prozac is 7 days.)
Finally, codeine itself is a cyp2d6 inhibitor. This means that taking the whole dose as quickly as possible will probably give you the biggest high (ie. its a waste to redose in 30 mins).
*GLUTHETHIMIDE
A combination of codeine and gluthethimide (a sleeping agent) has been used in some places as a heroin substitute. Gluthethimide is an enzyme-inducer, and it allows the body to convert more than 10% of codeine into morphine. Note that this combination increases the addiction potential of codeine.]
None (http://l2.espacenet.com/espacenet/viewer?PN=US2673205&CY=gb&LG=en&DB=EPD)
(http://l2.espacenet.com/espacenet/viewer?PN=US2673205&CY=gb&LG=en&DB=EPD) 8)