Hydrocodone is a semi-synthetic opioid synthesized from codeine, one of the opioid alkaloids found in the opium poppy. It is a narcotic analgesic used orally as an antitussive/ cough suppressant, but also commonly taken orally for relief of moderate to severe pain.n one study comparing the potency of hydrocodone to that of oxycodone, it was found that it took 50% more hydrocodone to achieve the same degree of miosis (pupillary contraction). The investigators interpreted this to mean that oxycodone is about 50% more potent than hydrocodone.