Skip to Content

The originating document has been archived. We cannot confirm the completeness, accuracy and currency of the content.

Morphine Sulfate

Pronunciation: moRE-feen SULL-fate
Class: Opioid analgesic

Trade Names

Astramorph PF
- Injection 0.5 mg/mL
- Injection 1 mg/mL

- Capsules, extended-release 30 mg
- Capsules, extended-release 45 mg
- Capsules, extended-release 60 mg
- Capsules, extended-release 75 mg
- Capsules, extended-release 90 mg
- Capsules, extended-release 120 mg

- Injection 0.5 mg/mL
- Injection 1 mg/mL

- Injection 10 mg/mL
- Injection 25 mg/mL

- Capsules, sustained-release 20 mg
- Capsules, sustained-release 50 mg
- Capsules, sustained-release 100 mg

MS Contin
- Tablets, controlled-release 15 mg
- Tablets, controlled-release 30 mg
- Tablets, controlled-release 60 mg
- Tablets, controlled-release 100 mg
- Tablets, controlled-release 200 mg

- Solution 10 mg per 5 mL
- Solution 20 mg per 5 mL
- Solution 20 mg/mL

Oramorph SR
- Tablets, controlled-release 15 mg
- Tablets, controlled-release 30 mg
- Tablets, controlled-release 60 mg
- Tablets, controlled-release 100 mg

OMS Concentrate
- Solution 20 mg/mL

- Rectal Suppositories 5 mg
- Rectal Suppositories 10 mg
- Rectal Suppositories 20 mg
- Rectal Suppositories 30 mg

- Solution 20 mg/mL

Roxanol Rescudose
- Solution 10 mg per 2.5 mL

Roxanol 100
- Solution 100 mg per 5 mL

Roxanol T
- Solution 20 mg/mL

Roxanol UD
- Solution 10 mg per 2.5 mL
- Solution 20 mg per 5 mL
- Solution 30 mg per 1.5 mL

M.O.S.-Sulfate (Canada)
Morphine HP Injection (Canada)
Morphine LP Epidural (Canada)
PMS-Morphine Sulfate SR (Canada)
ratio-Morphine SR (Canada)


Relieves pain by stimulating opiate receptors in CNS; also causes respiratory depression, peripheral vasodilation, inhibition of intestinal peristalsis, sphincter of Oddi spasm, stimulation of chemoreceptors that cause vomiting and increased bladder tone.



Mean T max is 3.7 h and mean C max is 9.9 to 27.4 ng/mL (dose dependent) for sustained-release form. Bioavailability is approximately 40%.


Morphine distributes to skeletal muscle, kidneys, liver, intestinal tract, lungs, spleen, and brain; crosses the placental membrane and is found in breast milk.


Virtually all converted into glucuronide metabolites; small fraction is demethylated in the liver. Major metabolite is morphine-3-glucuronide (55% to 75%).


The t ½ is approximately 2 to 4 h.


Onset is 15 to 60 min (intrathecal/epidural).


Duration is 3 to 7 h.

Indications and Usage

Relief of moderate to severe acute and chronic pain; relief of pain in patients who require opioid analgesics for more than a few days (sustained-release only); management of pain not responsive to nonnarcotic analgesics; dyspnea associated with acute left ventricular failure and pulmonary edema; preoperative sedation; adjunct to anesthesia; analgesia during labor.


Hypersensitivity to opiates; upper airway obstruction; acute asthma; diarrhea caused by poisoning or toxins.


Heart failure secondary to chronic lung disease; cardiac arrhythmias; brain tumor; acute alcoholism; delirium tremens; idiosyncrasy to the drug; convulsive states (eg, status epilepticus, tetanus, strychnine poisoning).

Immediate-release oral solution

Respiratory insufficiency; severe CNS depression; heart failure secondary to chronic lung disease; cardiac arrhythmias; increased intracranial or cerebrospinal pressure; head injuries; brain tumor; acute alcoholism; delirium tremens; convulsive disorders; after biliary tract surgery; suspected surgical abdomen; surgical anastomosis; idiosyncrasy to the drug; concomitantly with MAOIs or within 14 days of such treatment.


Infection at injection site; anticoagulation; bleeding condition; parenteral corticosteroids within past 2 wk; any other drug or condition that would contraindicate intrathecal/epidural therapy.

Dosage and Administration


PO 10 to 30 mg every 4 h as needed. Avinza 45 to 120 mg once daily only in opioid-tolerant patients. Subcutaneous/IM 5 to 20 mg/70 kg every 4 h as needed. IV 2.5 to 15 mg per 70 kg in water for injection 4 to 5 mL over 5 min as needed. IV (open-heart surgery) 0.5 to 3 mg/kg. IV (MI pain) 8 to 15 mg; for very severe pain, additional smaller doses may be given every 3 to 4 h. PR 10 to 20 mg every 4 h as needed. Epidural Initial injection of 5 mg may provide pain relief for up to 24 h; if pain is not controlled within 1 h, give incremental doses of 1 to 2 mg. Do not exceed 10 mg per 24 h. Intrathecal Usual dose is 10% of epidural dose. Single injection of 0.2 to 1 mg may provide pain relief for 24 h. Do not inject more than 2 mL of 5 mg per 10 mL ampule or 1 mL of 10 mg per 10 mL ampule. Repeat injections not recommended.


Subcutaneous/IM 0.1 to 0.2 mg/kg every 4 h.

Max dose

15 mg.

General Advice

  • Avinza must be swallowed whole; do not break, crush, chew, or dissolve).
  • If the patient cannot swallow the Avinza capsule whole, it may be opened and the contents sprinkled on a small amount of applesauce. Instruct the patient to swallow the applesauce mixture immediately and not to store for future use. Advise the patient that the applesauce mixture must not be chewed and the beads must not be crushed or dissolved due to the risk of acute overdose. Ingesting chewed or crushed Avinza beads will lead to the rapid release and absorption of a potentially toxic dose of morphine.


Store at room temperature (59° to 86°F).

Drug Interactions

Acyclovir, barbiturates, furosemides, heparin, sargramostim, sodium bicarbonate

Precipitation of IV solutions.

Antihistamines, chloral hydrate, glutethimide, methocarbamol

Depressant effects of morphine may be enhanced.


Monitor for increased respiratory and CNS depression. Concomitant administration of cimetidine and morphine has been reported to precipitate apnea, confusion, and muscle twitching in an isolated report.

Clomipramine, nortriptyline, amitriptyline

Monitor for increased CNS and respiratory depression when administered with morphine.

CNS depressants (eg, alcohol, sedatives, tranquilizers)

Additive CNS depression.

Laboratory Test Interactions

Increased amylase and lipase may occur up to 24 h after dose.

Adverse Reactions


Hypotension; orthostatic hypotension; bradycardia; tachycardia; palpitations.


Lightheadedness; dizziness; drowsiness; sedation; euphoria; dysphoria; delirium; disorientation; incoordination.


Sweating; pruritus; urticaria.


Blurred vision; miosis.


Nausea; vomiting; constipation; abdominal pain.


Urinary retention or hesitancy.


Respiratory depression; apnea; respiratory arrest; laryngospasm; depression of cough reflex.


Tolerance; psychological and physical dependence with chronic use; pain at injection site; local irritation and induration following subcutaneous use.



Monitor patient for at least 24 h after initial dose because of reports of severe adverse reactions with epidural/intrathecal use. Improper substitution of Infumorph for regular Duramorph may result in serious overdose.


Category C .


Excreted in breast milk.


Safety and efficacy not established.


Dosage reduction may be necessary.

Labor and Delivery

Therapeutic morphine doses have increased duration of labor.

Renal Function

May need to reduce dose.

Hepatic Function

May need to reduce dose.

Special Risk Patients

Use drug with caution in patients with myxedema, acute alcoholism, acute abdominal conditions, ulcerative colitis, decreased respiratory reserve, head injury or increased intracranial pressure, hypoxia, supraventricular tachycardia, depleted blood volume or circulatory shock.

Asthma and other respiratory conditions

Bisulfites and morphine may potentiate each other, preventing use by cause severe adverse reactions.

Drug dependence

Has abuse potential.



Miosis, respiratory and CNS depression, circulatory collapse, seizures, cardiopulmonary arrest, death.

Patient Information

  • Instruct patient to take oral preparations with food or juice if GI upset occurs.
  • Tell patient not to crush or chew controlled-release tablets.
  • Explain that full effectiveness of drug may not occur for 30 to 60 min after administration. Emphasize that drug is more effective if taken regularly to prevent pain rather than to treat pain after it occurs.
  • If patient is to receive patient-controlled analgesia (PCA), instruct on use of PCA pump.
  • Explain that physical dependency may occur with long-term therapy and that dosage will be tapered slowly before stopping to prevent withdrawal symptoms (nausea, vomiting, cramps, fever, faintness, anorexia).
  • Encourage patient to turn, cough and breathe deeply every 2 h to prevent atelectasis.
  • Advise patient to consult with health care provider if excessive sedation occurs or if pain relief is inadequate.
  • Inform patient that drug may cause constipation. Stool softener, fiber laxative, increased fluid intake and bulk in diet may help alleviate problem.
  • Caution patient to avoid sudden position changes to prevent orthostatic hypotension.
  • Instruct patient to avoid intake of alcoholic beverages and other CNS depressants.
  • Advise patient that drug may cause drowsiness, dizziness or blurred vision and to use caution while driving or performing other tasks requiring mental alertness.

Copyright © 2009 Wolters Kluwer Health.