Comparative Activity of Dihydrocodeine and Its Metabolites in the Electrically Stimulated Guinea‐pig Isolated Ileum

Lynette C.. Kirkwood, Michael G. Venning, Roger L. Nation, Geoffrey D Reynolds, Andrew A. Somogyi, Lloyd N. Sansom

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6 Citations (Scopus)

Abstract

The pharmacological potencies of dihydrocodeine and its metabolites, dihydrocodeine‐6‐glucuronide, nordihydrocodeine and dihydromorphine, were compared with morphine and codeine by measuring the influence on electrically stimulated contractions in the guinea‐pig isolated ileum. The mean (± standard error) EC50 of dihydromorphine (23 ± 3 nM) was similar to morphine (33 ± 3 nM) and these compounds were approximately 100 times more potent than dihydrocodeine (2660 ± 320 nM), nordihydrocodeine (2760±180 nM) and dihydrocodeine‐6‐glucuronide (2120 ± 230 nM). Dihydrocodeine and codeine were equipotent. These results suggest that dihydromorphine is a potent active metabolite of dihydrocodeine. Dihydromorphine formation from dihydrocodeine is catalysed by the polymorphically expressed cytochrome P450 2D6 in man; hence analgesia from dihydrocodeine may be dependent on expression of polymorphic CYP2D6. 1995 Royal Pharmaceutical Society of Great Britain

Original languageEnglish
Pages (from-to)573-575
Number of pages3
JournalPharmacy and Pharmacology Communications
Volume1
Issue number12
DOIs
Publication statusPublished - 1 Jan 1995
Externally publishedYes

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