Morphine

Morphine (INN), the principal active agent in opium, is a powerful opioid analgesic drug. 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 usually highly addictive, and tolerance and physical and psychological dependence develop quickly. Patients on morphine often report insomnia and nightmares.

Medical use

Administration

Morphine may be given parenterally as subcutaneous, intravenous, or epidural injections. The military sometimes issues morphine loaded in an autoinjector. Morphine can also be administered through a slow-release transdermal patch.

Related Topics:
Parenterally - Autoinjector

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Orally, it comes as an elixir, concentrated solution, powder (for compounding) or in tablet form. Morphine is rarely 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 forumations.

Related Topics:
Elixir - Solution - Powder - Bioavailability

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Uses

Morphine is used legally —

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• in the relief of acute, severe pain
• pain after surgery
• pain associated with trauma
• in the relief of moderate to severe chronic pain
• cancer pain
• tooth extraction
• 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 pancreatitis (this may be a result of morphine use as well)
• Renal failure (due to accumulation of the metabolite morphine-6-glucuronide)