Codeine Base is a natural alkaloid phenanthrene and opioid receptor agonist with analgesic, antidiarrheal and antitussive functions. Codeine binds to opioid receptors in the central nervous system and mimics the activity of endogenous opioids, reduces the release of nociceptive neurotransmitters such as dopamine, GABA, noradrenaline, and acetylcholine. Activation of the intestinal mu opioid receptor reduces intestinal motility and delays intestinal transit, thereby having anti-diarrheal action. Its antitussive action is also mediated by the effect of codeine on the cough center in the medulla.
