The Chemical Structure of Morphine

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Morphine It is the most important pharmacologically active constituent of opium, the resin copied from the dried juice of the opium poppy. It was first established into clinical practice more than 200 years ago. It is the prototype opioid drug, whose analgesic and rewarding effects are mediated by activating opioid receptors which are found mainly within the central nervous system (CNS). Morphine continues the strong opioid of choice for moderate to severe cancer pain and it is on the World Health Organization’s important drugs list. Cancer patients are usually unwilling to be managed with morphine as they fear its adverse effect and the risk of addiction or they have it as solely a comfort for the dying rather than a legitimate analgesic. Pharmacology The chemical structure of morphine is that a phenanthrene alkaloid, containing of five condensed rings which are structurally rigid. It is a weak base with a PK 7.9 and with PH 76% of its molecules is ionized and it is relatively water soluble and poorly lipid soluble. It is a available for management use because of the hydrochloride, sulphate and tartrate salts in large different formulations. Cancer patients prefer to take morphine orally than any other route of administration because of analgesic given regularly to prevent recurrence of pain usually for months or even years. Pharmacodynamics Morphine creates its effects by being an agonist at opioid receptors, located basically in the spinal cord and brain. It is a pure opioid agonist with primary affinity for the mu subclass of receptor, a member of the G- protein coupled receptor (GPCR) super family, while also some affinity for the kappa and delta subclasses. The most crucial responses mediated by activation of opioi... ... middle of paper ... ...the full effect of any dose alteration can be assessed at this time. Modified release (MR) morphine preparation has a slower onset of action and a later peak effect than NR formulations. There are twice-daily preparations with an onset of action of 1-2h, reaching peak drug levels at 4h. The once daily MR preparations have slower onset and reach peak levels at 8.5h. The most widely recognized side effects are sedation, respiratory depression and constipation as well as nausea and vomiting, while there are others common such as hpogonadism, immunosupression and tolerance as well as physical and psychological dependence. They can be reduced all these adverse effects of morphine by five possible approaches which are reducing the dose, changing the route and using opioid-spring adjuvant drugs as well as opioid rotation and symptomatic management of the side effect.

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