Suncodin Mechanism of Action

Pharmacology: Pharmacodynamics: The action of dihydrocodeine tartrate is almost purely analgesic. It is virtually free from sedative or hypnotic effects.
30mg given parenterally has been shown to have an analgesic potency equivalent to that of 10mg of morphine; in a study of oral analgesics for the relief of chronic pain, the same dose was found to be equivalent to 100mg of pethidine. In both trials, dihydrocodeine was found to have a lower incidence of side effects than either morphine or pethidine. It is fully active when administered orally and in the recommended doses, causes little or no respiratory depression; in addition to being a potent analgesic, the compound also exhibits well-defined antitussive activity.
Pharmacokinetics: The pharmacokinetics of dihydrocodeine may be similar to those of codeine.
There have been few pharmacokinetic studies of dihydrocodeine. In one study peak plasma concentrations of dihydrocodeine were achieved 1.6 to 1.8 hours after an oral dose of 30 and 60mg, respectively; elimination half-lives varied between about 3.5 and 4.5 hours. The rate of absorption was independent of dose and oral bioavailability was only about 20%, possibly because of substantial first-pass metabolism in the gut wall or liver.