Nicodicodeine is an opioid developed as a cough suppressant and analgesic. Synthesized in 1904, it is not commonly used, but has activity similar to other opioids. Nicodicodeine is metabolised in the liver by demethylation to produce 6-nicotinoyldihydromorphine, and subsequently further metabolised to dihydromorphine. Since the final active metabolite is the slightly stronger opiate dihydromorphine rather than morphine, nicodicodeine can be expected to be marginally more potent and longer acting than nicocodeine. Side effects are similar to those of other opioids and include itching, nausea and respiratory depression.