CODIENE/HYDROCODONE/OXYCODONE (pharmacokinetic profile)

Structure/Class
Pharmacodynamics
  1. As above
Absorption/administration
  1. PO
Distribution
Metabolism
  1. Codiene, hydrocodone and oxycodone are all hepatically metabolised by CYP 2D6.
    • Codiene is a partial µ-receptor agonist. Hepatic metabolism is crucial in codeine because codeine has a low affinity for the opioid receptor site.
    • Codiene is metabolised to morphine.
    • However, depending on CYP activity, a patient may actually receive no analgesia/be over-analgesed.
    • The activity of oxycodone and hydrocodone do not depend on hepatic metabolism.
Excretion
  1. Renal/urine
    • Oxycodone’s metabolites may accumulate in renal failure, leading to prolonged sedation.
Special notes