codeine brands

Molecular formula: C18H21NO3

Although the exact mechanism of action of codeine is still unknown, it is generally thought to be mediated through the agonism of opioid receptors, particularly the mu-opioid receptors. Morphine was previously postulated to contribute to the analgesic effect of codeine due to the O-demethylation of codeine to morphine by CYP2D6. Particularly, CYP2D6 poor metabolizer did not experience the analgesic effect of codeine. However, this is unlikely to be the main mechanism of action of codeine as only 5% of codeine is metabolized to morphine. Other hypotheses also postulate that codeine-6-glucuronide, the main metabolite of codeine, mediates the analgesic effect of codeine as it not only has an affinity to the mu receptors as codeine but also can be metabolized to morphine-6-glucuronide, which was observed to be more potent than morphine. Binding to the mu receptors by codeine activates the G-proteins Gα_i, causing a decrease in intracellular cAMP and Ca²⁺ level. This causes hyperpolarization of nociceptive neurons, thus imparing the transmission of pain signals. Codeine causes suppression of the cough reflex by a direct effect on the cough center in the medulla of the brain and appears to exert a drying effect on respiratory tract mucosa and to increase viscosity of bronchial secretions.

Source: PubChem (NCBI) · compound 5284371