How is codeine metabolised into morphine?
Codeine and morphine are metabolized to inactive compounds by UDP-glucuronosyltransferase enzymes (UGT). The enzyme UGT2B7—along with other UGT enzymes—is involved in conversion of codeine to codeine-6-glucuronide and morphine to morphine- 3- and 6-glucuronide (48).
What is the metabolite for morphine?
The main metabolite of morphine is morphine-3-glucuronide (M3G) (Figure 2). Morphine-6-glucuronide, however, has received the most scientific interest because, like mor- phine, it is an agonist at µ-opioid receptors.
What is the metabolite for codeine?
Codeine is an analgesic drug acting on μ-opiate receptors predominantly via its metabolite morphine, which is formed almost exclusively by the genetically polymorphic enzyme cytochrome P450 2D6 (CYP2D6).
Is codeine a prodrug of morphine?
Codeine, or methylmorphine, is an alkaloid found in opium, although most commercially available codeine is synthesized from morphine. Codeine is a prodrug that must be metabolized to its active metabolites, morphine and codeine 6-gluronide, to be effective.
What do morphine derivatives do?
Codeine and dihydrocodeine are morphine derivatives of low and moderate potency, respectively. Codeine is used in combination with paracetamol for the relief of mild to moderate pain.
What drugs are metabolized by CYP2D6?
Multiple tricyclic antidepressants, β blockers, haloperidol, sertraline, paroxetine, and thioridazine are among the common drugs metabolized by CYP2D6.
How many drugs does CYP2D6 metabolize?
7 With over 90 documented allelic variants reported, CYP2D6 displays remarkable polymorphism, sometimes with whole gene duplication. Overall, 20% to 30% of drugs are metabolized through this pathway, with more than 50 drug substrates known (see Table 3.2).
What metabolizes CYP2D6?
Cytochrome P450 CYP2D6 is the most extensively characterized polymorphic drug-metabolizing enzyme. The CYP2D6 enzyme catalyses the metabolism of a large number of clinically important drugs including antidepressants, neuroleptics, some antiarrhythmics, lipophilic β-adrenoceptor blockers and opioids.
What is the CYP2D6 * 10 allele?
CYP2D6 is a clinically important enzyme that metabolizes numerous therapeutic drugs. 16 Among the alleles of CYP2D6, CYP2D6*10 (C100T) is the most common allele in the Asian population, with a frequency of between 30% and 69.2%, where 13%–49% of the aforementioned population are homozygous for this allele.
What drugs are metabolized by cyp3a5?
The enzyme metabolizes drugs such as nifedipine and cyclosporine as well as the steroid hormones testosterone, progesterone and androstenedione. This gene is part of a cluster of cytochrome P450 genes on chromosome 7q21.
What percent of drugs are metabolized by CYP2D6?
CYP2D6 is a major gene member of this superfamily as it carries out metabolism of 25% of drugs currently available in the market.
What is metabolized by CYP2D6?
The CYP2D6 enzyme catalyses the metabolism of a large number of clinically important drugs including antidepressants, neuroleptics, some antiarrhythmics, lipophilic β-adrenoceptor blockers and opioids.
What drugs are metabolized to morphine?
During metabolism, around 60% of morphine becomes morphine-3-glucuronide and 6% to 10% becomes morphine-6-glucuronide. The morphine is glucuronidated by the phase II metabolism enzyme UDP-glucuronosyl transferase-2B7. The drug may also be metabolized into small quantities of normorphine, codeine, and hydromorphone.
Does codeine metabolize into morphine?
Codeine is metabolized within the body into morphine so a drug screen may come up positive for morphine. Your Dr should know this. He should know what a drugs metabolites are and that if you are prescribed codeine that you will have morphine excretion in the urine.
Is codeine a metabolite of morphine?
Codeine is a drug that has been used for years to treat mild and moderate pain. One of the ways that it is metabolized results in the formation of morphine, which is believed to be the metabolite that makes codeine effective as a pain reliever.
What is the peak effect of morphine?
Nausea, vomiting, constipation, lightheadedness, dizziness, drowsiness, increased sweating, or dry mouth may occur. Pain, redness, or swelling at the injection site may occur if this medication is given into a muscle or under the skin. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.