Pethidine Ranitidine

ALFENTANIL, FENTANYL, PETHIDINE, TRAMADOL CIMETIDINE Cimetidine may t fentanyl, pethidine and tramadol levels Cimetidine inhibits CYP2D6-medi-ated metabolism of these opioids. Ranitidine weakly inhibits CYP2D6 Watch for excessive narcotization... 

No clinically significant interaction appears to occur between ci-metidine and butorphanol (intranasal), hydromorphone, morphine, pethidine or tramadol between famotidine and hydromorphone or between ranitidine and hydromorphone, morphine, or pethidine. However, isolated reports describe adverse reactions in patients taking methadone, morphine or mixed opium alkaloids with cimetidine, or morphine with ranitidine. 

Cimetidine 600 mg twice daily for one week reduced the total hody clearance of a single 70-mg intravenous dose of pethidine in 8 healthy subjects by a modest 22%." In a similar study by the same research group, ranitidine 150 mg twice daily had no effect on pethidine pharmacokinetics. ... 

Information about the interaction between pethidine and cimetidine is very limited, and its clinical importance is uncertain, but probably small given the minor changes in pharmacokinetics. However, some manufacturers warn that cimetidine may inhibit the metabolism of pethidine and thus caution should be used with concurrent use. Ranitidine has been shown not to affect the pharmacokinetics of pethidine. 

Guay DRP, Meatherall RC, Chalmers JL, Grahame GR, Hudson RJ. Ranitidine does not alter pethidine disposition in man. BrJ Clin Pharmacol (1985) 20, 55-9. 

---

See also in sourсe #XX -- [ ]

---