Morphine and its preparations

24th December 2006 at 10:48 GMT by Dr C.A.Jenner MB BS, FRCA. Permalink.

Article on the uses, mechanisms and adverse effects of morphine and morphine preparations in the management of pain

Introduction to Morphine

Morphine is a powerful drug of the opiate, analgesic nature and is the principal active agent in opium.

Morphine belongs to a class of drugs known as narcotic analgesics and is used to treat moderate-to-severe pain. The drug produces the desired effect by changing the way the body senses pain.

As with other opioids, morphine also directly acts on the central nervous system to relieve pain. Morphine is marketed under generic and brand names including MS-Contin®, Oramorph®, MSIR®, Roxanol®, Kadian® and RMS®.

Like most narcotics, the use of morphine has increased significantly in the recent years. Since 1990, there has been an almost 3-fold increase in morphine products in the United States.

Uses of Morphine

Morphine long-acting tablets and capsules are to be used only by patients who are expected to need medication to relieve moderate to severe pain around-the-clock for longer than a few days.

There are a certain set of guidelines, which allow the legal use of morphine. The main forms of use include:

1. Analgesic in hospital settings for Pain after surgery and Pain associated with trauma
2. In the relief of severe chronic pain associated with: Cancer pain, Pain from kidney stones and severe Back pain
3. As an adjunct to general anesthesia
4. In epidural anesthesia
5. For palliative care
6. As an antitussive for severe cough
7. As an antidiarrheal in chronic conditions

Adverse effects of Morphine

Side effects of the use of morphine include:

• Impairment of mental performance
• Euphoria
• Drowsiness, lightheadedness
• Lethargy
• Vomiting
• Blurred vision
• Decrease in hunger
• Inhibition of cough reflex
• Constipation
• Stomach pain
• Insomnia
• Difficulty in urinating
• Visual hallucinations
• Nightmares

Some of the more serious side effects include:

• Acute respiratory depression
• Acute alcoholism
• Acute pancreatitis
• Renal failure

Dosage of Morphine

Morphine is marketed in a variety of forms, including oral solutions, immediate and sustained-release tablets and capsules, suppositories and injectable preparations.

• The regular tablet and liquid are usually taken after every 4 hours.
• The long acting tablet is usually taken after every 8-12 hours.
• Kadian® brand long-acting capsules are taken every 12 or 24 hours.
• Avinza® brand long-acting capsules are usually taken once a day.

Some of the main guidelines regarding the dosage of morphine are:

Wrong dosage of morphine can prove quite hazardous. You must make sure to read the prescription label carefully and ask your doctor or pharmacist to explain any part you do not understand.

Things to consider when using Morphine

When consuming morphine in any form, it is extremely important to remember a few basic facts about the drug. Here we list some of the most important points:

• Do not stop taking morphine suddenly, if you have been taking the drug continuously for more than 5 days.
• Do not crush, chew, break or open controlled-release forms of morphine such as Oramorph SR, Kadian and MS Contin. Instead, swallow them whole.
• Drink plenty of water to reduce the possible risk of constipation due to the drug.
• Never take more morphine than prescribed by the doctor.