Morphine
This article is about the opiate. See Morphine (band) for information about the alternative rock group.) is an extremely powerful
opiate analgesic drug and is the principal active agent in
opium. Like other
opiates, 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 and
nightmares.
The word "morphine" is derived from
Morpheus, the god of
dreams in
Greek mythology.
Administration
Morphine may be given
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* 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)
* To relieve breathlessness in patients in respiratory failure
Contraindications
*
Acute pancreatitis (this may be a result of morphine use as well)
*
Renal failure (due to accumulation of the metabolite
morphine-6-glucuronide)
Morphine is an
opioid receptor agonist â€" 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.
*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).[
1]
*Internationally, morphine is a Schedule I drug under the
Single Convention on Narcotic Drugs[
2].
Morphine was first isolated in
1804 by the German pharmacist
Friedrich Wilhelm Adam Sertürner, 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 resulted in over 400,000 sufferers from the "soldier's disease" (addiction), though some believe this to be erroneous [
3].
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 the most sought after prescription narcotic 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.
*
Heroin*
Opioid*
Psychoactive drug*
Morphine Apparently in Your Head --
Wired Magazine article about endogenous production of morphine
*
Morphine,
Molecule of the Month*
Morphine news page -
Alcohol and Drugs History Society
