From the Research
Effectiveness of Dihydrocodeine
- The effectiveness of dihydrocodeine when administered intrarectally is not directly addressed in the provided studies 1, 2, 3, 4, 5.
- However, a study on rectal absorption of codeine phosphate, a related compound, found that rectal absorption from an aqueous solution or a fatty suppository produced an almost identical plasma concentration profile with similar interindividual variations compared to oral dosing 1.
- Another study on dihydrocodeine found that the analgesic effect of dihydrocodeine is similar to codeine and approximately twice as potent as tramadol for an oral route 2.
- A study on the pharmacokinetics of intravenous and oral dihydrocodeine found that the mean bioavailability of orally administered dihydrocodeine was 21% (range 12-34%) 3.
- Post-marketing surveillance studies have shown that dihydrocodeine is an effective and safe analgesic drug for the treatment of chronic pain of various causes 4, 5.
Administration Routes
- The provided studies primarily focus on oral and intravenous administration of dihydrocodeine, with one study mentioning rectal absorption of codeine phosphate 1.
- There is no direct evidence on the effectiveness of dihydrocodeine when administered intrarectally in the provided studies.
Pharmacokinetics and Pharmacodynamics
- The pharmacokinetics of dihydrocodeine have been studied, with findings indicating a two-compartment distribution model and a mean half-life of 3.3-4.5 hours 3.
- The pharmacodynamics of dihydrocodeine have also been studied, with findings indicating that the analgesic effect of dihydrocodeine is probably twice as potent as codeine for the parenteral and slightly stronger for an oral route 5.