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Morphine

2007 Schools Wikipedia Selection. Related subjects: Chemical compounds;
Health and medicine

                                               Morphine chemical structure

   Morphine

                                                  Systematic ( IUPAC) name
                                                            7,8-didehydro-
                                    4,5-epoxy-17-methyl morphinan-3,6-diol
                                                               Identifiers
                                                        CAS number 57-27-2
                                                         ATC code N02 AA01
                                                           PubChem 5288826
                                                        DrugBank APRD00215
                                                             Chemical data
                                                  Formula C[17]H[19]NO[3]^
                                                         Mol. weight 285.4
                                                      Pharmacokinetic data
                                                      Bioavailability ~30%
                                                  Protein binding 30–40%
                                                    Metabolism Hepatic 90%
                                                     Half life 2–3 hours
                                          Excretion Renal 90%, biliary 10%
                                                Therapeutic considerations
                                                            Pregnancy cat.

                                                               C(AU) C(US)
                                                              Legal status

   S8(AU) Schedule I(CA) Class A(UK) Schedule II(US) ℞ Prescription only
                                       Dependence Liability Extremely High
                     Routes smoked/ inhaled, insufflated, Oral, SC, IM, IV

   Morphine ( INN) ( IPA: [ˈmɔ(ɹ)fin]) is an extremely powerful opiate
   analgesic drug and is the principal active agent in opium. Like other
   opioids, e.g. heroin, morphine acts directly on the central nervous
   system (CNS) to relieve pain, and at synapses of the arcuate nucleus,
   in particular. Side effects include impairment of mental performance,
   euphoria, drowsiness, lethargy, and blurred vision. It also decreases
   hunger, inhibits the cough reflex, and produces constipation. Morphine
   is highly addictive when compared to other substances, and tolerance
   and physical and psychological dependence develop quickly. Patients on
   morphine often report insomnia, visual hallucinations and nightmares.
   Used in ACS "Chest Pain believed to be of cardiac origin" as an adjunct
   to nitroglycerine providing pain relief, decreasing patient anxiety and
   minimal coronary artery dilation, which helps oxygenate the heart.

   The word "morphine" is derived from Morpheus, the god of dreams in
   Greek mythology. He is the son of Somnus, god of sleep.

Medical use

Administration

   Parenterally as subcutaneous, intravenous, or epidural injections. When
   injected, particularly intravenously, morphine produces an intense
   contraction sensation in the muscles and thus produces a powerful
   'rush'. The military sometimes issues morphine loaded in an
   autoinjector.

   Orally, it comes as an elixir, concentrated solution, powder (for
   compounding) or in tablet form. Morphine is rarely supplied in
   suppository form. Due to its poor oral bioavailability, oral morphine
   is only one-sixth to one-third of the potency of parenteral morphine.
   Morphine is available in extended-release capsules for chronic
   administration, as well as immediate-release formulations.

Uses

   Morphine is used legally:
     * analgesic in hospital settings for
          + Pain after surgery
          + Pain associated with trauma
     * In the relief of severe chronic pain
          + Cancer pain
          + Pain from kidney stones
          + Back pain
     * As an adjunct to general anesthesia
     * In epidural anesthesia
     * For palliative care (i.e. to alleviate pain without curing the
       underlying reason for it)
     * As an antitussive for severe cough
     * As an antidiarrheal in chronic conditions (e.g., for diarrhea
       associated with AIDS)

Contraindications

     * acute respiratory depression
     * acute alcoholism
     * acute pancreatitis (this may be a result of morphine use as well)
     * renal failure (due to accumulation of the metabolite
       morphine-6-glucuronide)

Pharmacology

                                                            Indicated for:
     * Relief of extreme pain

                                                        Recreational uses:
     * Euphoria
     * Relaxation

                                                               Other uses:
     * Pain relief
     * Cough suppressant
     * anti- diarrheal

                                                        Contraindications:
     * Alcohol
     * Barbiturates and Benzodiazepines
     * Stimulants
     * Other opioids (depends heavily on tolerance)

                                                             Side effects:

   Severe:
     * Respiratory arrest
     * Spontaneous abortion

                                                      Atypical sensations:
     * ?

                                                           Cardiovascular:
     * Lowered heart rate

                                                    Ear, nose, and throat:
     * Dry mouth

                                                               Endocrinal:
     * Eugonadism

                                                                      Eye:
     * Pupil constriction
     * Intermittent blurring

                                                         Gastrointestinal:
     * Nausea
     * Constipation

                                                            Hepatological:
     * none

                                                            Hematological:
     * ?

                                                         Musculo skeletal:
     * ?

                                                             Neurological:
     * Analgesia

                                                            Psychological:
     * Anxiolysis
     * Confusion
     * Euphoria
     * Sedation

                                                              Respiratory:
     * Slow and shallow respiration

                                                                     Skin:
     * Itchiness
     * Flushing

   Morphine is an phenanthrene opioid receptor agonist – its main effect
   is binding to and activating the µ-opioid receptors in the central
   nervous system. Activation of these receptors is associated with
   analgesia, sedation, euphoria, physical dependence and respiratory
   depression. Morphine is also a κ-opioid receptor agonist, with this
   action associated with spinal analgesia and miosis.

   Like loperamide and other opioids, morphine acts on the myenteric
   plexus in the intestinal tract reduce gut motility, leading to
   constipation.

   The effects of morphine can be countered with naloxone or naltrexone.

   Morphine is primarily metabolized into morphine-3-glucuronide and
   morphine-6-glucuronide. Morphine-6-glucuronide (M6G) has been found to
   be a far more potent analgesic than morphine when dosed to rodents. M6G
   has also been found to be analgesic in humans. The significance of M6G
   formation on the observed effect of a dose of morphine is the subject
   of extensive debate among pharmacologists.

   High doses of morphine may be fatal due to respiratory depression.
   Nevertheless, patients in extreme pain are able to tolerate very high
   doses of morphine. This is because pain stimulates respiration, thus
   counteracting the respiratory depression.

Chemistry

   Most of the morphine produced is used to make codeine. It is also a
   precursor for both diamorphine and hydromorphone. Replacement of the
   N-methyl group of morphine with an N-phenylethyl group results in a
   product that is 18x morphine in it's opiate against potency.

Legal classification

     * In the United Kingdom, morphine is listed as a Class A drug under
       the Misuse of Drugs Act 1971.

     * In the United States, morphine is classified as a Schedule II drug
       under the Controlled Substances Act.

     * In Australia, morphine is classified as a Schedule 8 drug under the
       Therapeutic Goods Act 1989 (2003).

     * Internationally, morphine is a Schedule I drug under the Single
       Convention on Narcotic Drugs .

History and abuse

   Morphine was first isolated in 1804 by the German pharmacist Friedrich
   Wilhelm Adam Sertürner (or Barnard Courtois), who named it "morphium"
   after Morpheus, the Greek god of dreams. But it was not until the
   development of the hypodermic needle ( 1853) that its use spread. It
   was used for pain relief, and as a "cure" for opium and alcohol
   addiction. Its extensive use during the American Civil War allegedly
   resulted in over 400,000 sufferers from the "soldier's disease" of
   morphine addiction, although critics believe this to be a highly
   erroneous and misleading claim, pointing to the glaring lack of
   documented post-war cases .

   Heroin (diacetylmorphine) was derived from morphine in 1874. As with
   other drugs, its possession without a prescription was criminalized in
   the U.S. by the Harrison Narcotics Tax Act of 1914.

   Morphine is routinely carried by soldiers on operations in an
   autoinjector.

   Morphine was the most commonly abused narcotic analgesic in the world
   up until heroin was synthesized and came into use. Even today, morphine
   is one of the most sought after prescription narcotics by heroin
   addicts when heroin is scarce.

   In a randomised double-blind study with crossover at an outpatient
   clinic in Bern, Switzerland, morphine was proven to have stronger
   side-effects than heroin at equianalgesic doses. Respiratory
   depression, miosis, sedation, itchiness, and euphoria were more
   pronounced with morphine.

   Retrieved from " http://en.wikipedia.org/wiki/Morphine"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
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