The term morphine is used colloquially for the opiate morphine. It is one of the opioid analgesics and is strictly available by prescription in any dosage form. Since the risk of abuse is very high and the drug has very many strong side effects in addition to the desired effects, it is subject to the Narcotics Act (BtmG) in any dosage form and may also only be prescribed and dispensed on a BtmG prescription.
What is morphine?
Morphine finds its application in medicine in the first place as a strongly effective analgesic when other painkillers are no longer strong enough. The dosage forms can be different. Morphine is a very strong analgesic from the group of opiates, as it is a main alakaloid of opium. In medicine it finds its use as one of the strongest natural painkillers ever. It is an alkaloid isolated in its purest form. This isolation was achieved in 1805 by the pharmacist Friedrich Wilhelm Adam Sertürner from Paderborn, who named the newly discovered substance after the Greek god of dreams “Morpheus”. The composition, which is also widely known today as a drug, was only later named morphine. Morphine has its origin in the milky sap of the opium poppy, which is dried for extraction. The synthesis from the basic substance of the opium poppy is associated with very high effort and the result from the extraction process with about 10% relatively low.
Pharmacological action
Morphine acts as an analgesic completely different from other analgesics. It acts centrally via so-called opioid receptors in the brain. Through the action of the agonist, pain transmission is inhibited, which results in the morphine-consuming patient no longer perceiving pain or only perceiving it in a diminished form. This occurs because the μ-receptors are activated by the action of the morphine. Morphine is usually very well absorbed by the body. Since the conversion or metabolization in the liver , which is also called the first pass effect, is very high, the bioavailability is very low and the duration of action is relatively short at 2-4 hours measured against the potency of the analgesic. Morphine does not exhibit the so-called ceiling effect, also known as the saturation effect. This means that the effects also increase with increasing consumption. Since morphine has not only the positive effect of pain relief but also a whole series of unpleasant side effects, life-threatening poisoning can occur due to the lack of a ceiling effect. The undesirable side effects in pain therapy are very welcome in intentional morphine abuse. These can be produced relatively quickly, which is why pure morphine in any dosage form has been made subject to narcotics laws.
Medical application and use
Morphine finds its application in medicine in the first place as a strongly effective analgesic when other painkillers are no longer strong enough to combat or relieve the pain. There are various forms of administration: liquid as drops and injection solution, for oral application as tablets, effervescent tablets, capsules, sustained-release capsules and granules, and for cases where swallowing is not possible and injection is undesirable or inappropriate, as suppositories. The so-called morphine patch does not contain morphine as the active ingredient, as is often erroneously assumed, but the much more potent opioid fentanyl. In an international comparison, morphine is prescribed much less frequently in Germany than in neighboring Denmark. On the one hand, people are afraid of the strong side effects. The main reason why only about 5% of patients in Germany who need a painkiller of this strength actually receive morphine is that morphine is subject without restriction to the BtmG and doctors are reluctant to issue these Btm prescriptions because of the additional expense and the obligation to provide proof. In order to reduce the undesirable and sometimes dangerous side effects, the WHO advises that morphine should be administered orally only, if possible, and that the dose actually required should be approached individually until pain titration is achieved. Morphine should also not be used as monotherapy for pain control, but rather in combination with another, non-centrally acting analgesic, if possible.
Risks and side effects
The more potent a drug is, the higher its side effects and associated risks usually are. The very fact that morphine is a centrally acting analgesic used in the treatment of severe to very severe pain makes the range of risks quite large. However, since the duration of action is relatively short at 2-4 hours and the centrally depressant, but usually also euphoric effect at the beginning of treatment is perceived as pleasant by the consuming patients, the craving for another dose arises very quickly. Morphine has a very high physical and psychological dependence potential. In addition, it not only has an inhibitory effect on pain transmission at the opiate receptors in the brain, but with increasing dosage it also has an inhibitory effect on the respiratory center, which can lead to respiratory arrest. Other side effects include nausea with vomiting, especially at the beginning of treatment, and constipation. Hallucinations and impaired consciousness that occur may be particularly unpleasant.