Codeine is a drug that is primarily used to relieve pain.
What is codeine?
Codeine is a drug used primarily to relieve pain. Codeine is one of the opioids. In medicine, it is used in two areas, as a pain reliever or medicine for cough suppression. Codeine is made from opium sap, so it is a natural compound. Unlike earlier times when codeine was often prescribed for coughs, most doctors have become quite cautious with it today because of the risk of side effects.
Pharmacological action
With regard to the effects of codeine as a drug, there are large genetic differences in the population. In some people, codeine has hardly any effect due to their genetic characteristics, while in others it has such a strong effect that they should refrain from taking the drug. Codeine has different analgesic effects in the body. About 10% of the curative effect can be explained by the formation of the active metabolite morphine, which occurs through a demethylation process in the body. More than 400 mg of codeine is no longer effective because at a higher dosage, codeine can no longer be metabolized in the body. At normal dosages of codeine, approximately 10% of this substance is excreted unchanged by the kidneys. The remainder also leaves the organism via the kidneys in the form of codeine conjugates or else morphine conjugates.
Medical application and use
In general, codeine is effective against pain as well as very good for cough. Medications containing codeine are prescribed particularly frequently for irritable coughs. In COPD, the effect is considered questionable. Before methadone could be manufactured, codeine was also often used in the past as a helpful remedy for overcoming heroin addiction. For moderate to severe pain, medications containing codeine are still often prescribed in combination with other pain medications. These complementary medications include acetaminophen, diclofenac, or acetylsalicylic acid. Codeine, when prescribed for irritable cough, is often given in liquid form. These may be drops or cough syrup containing codeine. There are also codeine-containing medications that come in tablet or capsule form. Normally, codeine in many medications has a plasma half-life of 2 to 3 hours and can be broken down by the body fairly quickly. However, this is not the case with every codeine-containing medication. Codeine also exists in the form of sustained-release medications. In this case, binding to the cation exchanger codeine poly(styrene, divinylbenzene) sulfonate takes place, which in turn leads to a much longer half-life of codeine in the body and in this respect contributes to a longer duration of action.
Risks and side effects
Codeine is one of those medications that are prescribed by many physicians only with the greatest caution because of the side effects that frequently occur, some of which are very severe. The side effects are not always life-threatening but rather to be classified as harmless. The harmless side effects of codeine include constipation, nausea, vomiting and fatigue. Codeine has often been particularly dangerous in infants and children. The active ingredient can be passed to the infant through breast milk if the mother takes medications containing codeine. Thus, somnolence (sleepiness), lethargy, and weakness in drinking have often occurred in breastfed infants when mothers have been treated with codeine. Very severe side effects have been reported in some cases during codeine treatment of children themselves. In most cases, these were respiratory depression. Codeine should therefore no longer be prescribed for children if possible. In Germany, codeine falls under the Narcotics Act and is generally available only on prescription. It may normally only be dispensed in low doses to persons not dependent on narcotics or alcohol.
