What is codeine ?
Codeine is 3 mono-methyl ether of morphine. It is an alkaloid which is found in opium in concentrations of between 0.7 to 3.0 percent.
Codeine can be made of morphine. It is an opiate agonist, which explains that the pharmacological effects of codeine are more or less comparable to those of morphine. The liver converts codeine into morphine for a part. In some people, the enzyme responsible for this metabolism is not present, which makes them less effective for codeine. Compared with morphine codeine per milligram a weak painkiller and also a powerful tickling cough suppressant. Works codeine and strong sedative obstiperend. In the Netherlands, codeine registered for oral use only. Equivalent: 100 mg codeine is approximately equal to oral morphine 10 mg and 100 mg codeine is also equal to 3,5 mg morphine via injection. Yet this comparison is not a good indicator. The side effects are much milder than the side effects of morphine per milligram.
Pharmacokinetics
Absorption: Good. Metabolism: in the liver via CYP3A4 for 80% to norcodeïne which is then glucuronised. 10% via CYP2D6 to morphine. Elimination: with the urine unchanged (10%) and as metabolites. Plasma half-life is 3 to 4 hours, hepatic longer in overdose 6 hours.
But by genetic polymorphism exists an individual variability in the decomposition of codeine. At about 5% of the population is codeine converted more slowly in the active metabolites, mainly morphine. These so-called poor metabolizers experienced a reduced analgesic effect of codeine. Less frequent (1 to 3% of our population) but clinically more relevant are the so-called ultrarapid metabolizers. A larger percentage of the codeine than the aforementioned 10% is converted to morphine with them at the risk of overdose even at normal therapeutic amounts. Serious consequences are described as the death of a baby by morphine poisoning through breast milk from a mother who used acetaminophen/codeine as a combination preparation postnatal pain reliever (less than 60 mg codeine per day). After genotyping revealed this mother a ultrarapid metabolizers of CYP2D6. About 6.5% of the European population are CYP2D6 ultra-rapid metabolisers but there is a big difference in prevalence depending on race and ethnic origin.
Codeine side effects
Often
- Constipation
- Drowsiness, sleepiness and decreased responsiveness
- Dizziness
- Difficulty urinating
- Masking of other pain
- Fluid retention
- Itch
- Hypersensitivity to codeine
- Respiratory depression (especially in overdose)
Overdose
At an overdose of codeine can cause serious side effects occur, such as oppression of breathing, epilepsy-like seizures (convulsions), loss of consciousness or coma and shock. The initial signs of overdose include vomiting, nausea and myosis. An intravenous administration of naloxone along with artificial support of breathing is the preferred treatment at an overdose with severe respiratory depression. A normal dose is 10 mg per dose for cough complaints and to combat the pain is 40 mg-60 mg a normal dose. The maximum dose is 240 mg spread across 24 hours in 4 dose of 60 mg codeine. Between 2 doses must be at least 4 hours.
Addiction
Addiction can occur. The risk of addiction to a strong opiate like morphine, is many times higher. The addictive substance is, however, also because morphine codeine is partially converted to morphine. An addiction should be excluded because the acute withdrawal of the drug can cause withdrawal symptoms such as tremors and / or a delirium. In normal use according to prescription is the risk of addiction very small.
Simultaneous consumption of alcohol and a high dose of codeine can be fatal because alcohol may increase the respiratory depressant effect. Hospitalization is necessary and the antidote is naloxone. It eliminates the effects of opiates and opioids. Codeine is partly under the Opium Act.
Trivia
- Codeine is frequently prescribed as a painkiller in Anglo-Saxon countries than in the Netherlands.
- Codeine can be extracted from the opium.
- Adding codeine to paracetamol increases the therapeutic effect (pain relief) only slightly, but it helps well in neuropathic pain. A dose 500/10 (500mg acetaminophen with codeine 10mg) has little value than paracetamol alone. The dose 500/20 already provides a better therapeutic effect and dose 500/50 has been beneficial and works strong. For strong pain relief is 40-60mg the most effective dosage. If this does not help, another stronger opiate better.
- Codeine is a second degree analgesic which works stronger than the first degree agents such as acetaminophen and ibuprofen, the NSAIDs.
- If you continue to use the cons are likely to outweigh the benefits; the development of tolerance and abuse (addiction).
- Codeine is the raw material for crocodile, prepare a home heroin substitute which is popular in Russia.