Dihydrocodeine (DHC) is a semi-synthetic analogue of codeine, which was formed by the hydrogenation of the double tie in the main chain of the codeine molecule - instead of a double bond between carbons 7 and 8 DHC possesses a single bond. DHC is used as an analgesic and antitussive agent and for the management of dyspnea and opioid addiction. Limited data is available on the potency of DHC to other opioids. The analgesic effect of DHC is similar to codeine and approximately twice as potent as tramadol for an oral route. In contrast to codeine and tramadol, DHC analgesia seem to be irrespective of CYP2D6 activity due to parent compound analgesic effects, multiple metabolic pathways and limited role of dihydromorphine in DHC analgesia. As the drug is commonly available appropriate titration and dosing and knowledge of its metabolism and possible adverse effects are important for safe prescription of DHC.
Keywords: adverse effects; analgesia; dihydrocodeine; opioids; safety.