Role of active metabolites in the use of opioids

@article{Coller2008RoleOA,
  title={Role of active metabolites in the use of opioids},
  author={Janet K. Coller and Lona Louring Christrup and Andrew Alexander Somogyi},
  journal={European Journal of Clinical Pharmacology},
  year={2008},
  volume={65},
  pages={121-139}
}
The opioid class of drugs, a large group, is mainly used for the treatment of acute and chronic persistent pain. All are eliminated from the body via metabolism involving principally CYP3A4 and the highly polymorphic CYP2D6, which markedly affects the drug’s function, and by conjugation reactions mainly by UGT2B7. In many cases, the resultant metabolites have the same pharmacological activity as the parent opioid; however in many cases, plasma metabolite concentrations are too low to make a… 
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