Opioids, specific agents codeine

Few studies have explored the efficacy of opioids specifically for OA. The APS recommends against the use of codeine and propoxyphene for OA because of the high incidence of adverse effects and limited analgesic effectiveness. Oxycodone is the most extensively studied of the agents recommended for OA. However, other narcotic analgesics such as morphine, hydromorphone, methadone, and transdermal fentanyl are also effective. 

Alkaloids such as boldine, codeine, narceine and morphine are active factors in their receptors. Boldine has morphine-like properties and is active on opioid receptors. It may be used to treat stomach disorders and as metabolic stimulant. As it is similar to morphine, boldine can also be considered in the possible development of treatments for narcotic dependence. Codeine also binds to opiate receptors, and specifically functions to reduce bronchial secretions. Codeine can also be used as a cough suppressant when acting on the centre of the medulla oblongata and as a sedative agent. 

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