Codeine is Found in These Foods
Top Gene Interactions
- Metabolism: Hepatic. Codeine is a prodrug, itself inactive, but demethylated to the active morphine by the liver enzyme CYP2D6 to morphine. 70-80% of the dose undergoes glucuronidation to form codeine-6-glucuronide. This process is mediated by UDP-glucuronosyltransferase UGT2B7 and UGT2B4. 5-10% of the dose undergoes O-demethylation to morphine and 10% undergoes N-demethylation to form norcodeine. CYP2D6 mediates the biotransformation to morphine. CYP3A4 is the enzymes that mediates the conversion to norcodiene. Morphine and norcodeine are further metabolized and undergo glucuronidation. The glucuronide metabolites of morphine are morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G). Both morphine and morphine-6-glucuronide are active and have analgesic activity. Norcodiene and M3G do not have any analgesic properties. Route of Elimination: 90% of the total dose of codeine is excreted through the kidneys, of which 10% is unchanged codeine. Half Life: Plasma half-lives of codeine and its metabolites have been reported to be approximately 3 hours.
- Uses/Sources: For treatment and management of pain (systemic). It is also used as an antidiarrheal and as a cough suppressant.
- Health Effects: Medical problems can include congested lungs, liver disease, tetanus, infection of the heart valves, skin abscesses, anemia and pneumonia. Death can occur from overdose.
- Symptoms: Respiratory depression, sedation and miosis and common symptoms of overdose. Other symptoms include nausea, vomiting, skeletal muscle flaccidity, bradycardia, hypotension, and cool, clammy skin. Apnea and death may ensue.
- Treatment: Naloxone antagonizes most effects of codeine. Protect the airway as Naloxone may induce vomiting. Naloxone has a shorter duration of action than codeine; repeated doses may be needed. Protect the patient's airway and support ventilation and perfusion. Meticulously monitor and maintain, within acceptable limits, the patient's vital signs, blood gases, serum electrolytes, etc. Absorption of drugs from the gastrointestinal tract may be decreased by giving activated charcoal, which in many cases, is more effective than emesis or lavage; consider charcoal instead of or in addition to gastric emptying. Repeated doses of charcoal over time may hasten elimination of some drugs that have been absorbed. Safeguard the patient's airway when employing gastric emptying or charcoal. (L1712)
- Route of Exposure: Oral, Intramuscular. Well absorbed following oral administration with a bioavailability of approximately 90%. Maximum plasma concentration occurs 60 minutes post-administration. Food does not effect the rate or extent of absorption of codeine.
Mechanism of Action
|Target Name||Mechanism of Action||References|
Potassium voltage-gated channel subfamily H member 2
Cytochrome P450 2D6
Mu-type opioid receptor
Kappa-type opioid receptor
Delta-type opioid receptor
|Opiate receptors are coupled with G-protein receptors and function as both positive and negative regulators of synaptic transmission via G-proteins that activate effector proteins. Binding of the opiate stimulates the exchange of GTP for GDP on the G-protein complex. As the effector system is adenylate cyclase and cAMP located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine and noradrenaline is inhibited. Opioids also inhibit the release of vasopressin, somatostatin, insulin and glucagon. Codeine's analgesic activity is, most likely, due to its conversion to morphine. Opioids close N-type voltage-operated calcium channels (OP2-receptor agonist) and open calcium-dependent inwardly rectifying potassium channels (OP3 and OP1 receptor agonist). This results in hyperpolarization and reduced neuronal excitability.||
Codeine Interacts with Diseases
|Disease||Inference Score||References/Inference Genes|
|Short QT Syndrome 1||5.76||
|Drug Metabolism, Poor, CYP2D6-Related||5.69|
|Long Qt Syndrome 2||5.07||
|Torsades de pointes||4.9||
|Eye Infections, Bacterial||4.87||