Generic name: morphine (injection) [ MOR-feen ]
Brand names: Duramorph PF, Infumorph, Mitigo
Dosage forms: injectable solution (0.5 mg/mL preservative-free; 1 mg/mL; 1 mg/mL preservative-free; 1 mg/mL-NaCl 0.9% preservative-free; 10 mg/mL preservative-free; 2 mg/mL preservative-free; 25 mg/mL preservative-free; 4 mg/mL preservative-free; 5 mg/mL preservative-free; 50 mg/mL; 8 mg/mL preservative-free), ... show all 2 dosage forms intravenous solution (0.5 mg/mL-NaCl 0.9% preservative-free; 1 mg/mL preservative-free; 1 mg/mL-NaCl 0.9%; 1 mg/mL-NaCl 0.9% preservative-free; 10 mg/mL preservative-free; 2 mg/mL preservative-free; 2 mg/mL-NaCl 0.9%; 200 mg/200 mL-D5%; 4 mg/mL preservative-free; 4 mg/mL-NaCl 0.9% preservative-free; 5 mg/mL-NaCl 0.9%; 8 mg/mL preservative-free)
Drug class: Opioids (narcotic analgesics)

Medically reviewed by Drugs.com on Mar 31, 2025. Written by Cerner Multum.

What is morphine?

Morphine is an opioid medicine used to treat severe chronic pain in adults and children.

Morphine may also be used for purposes not listed in this medication guide.

Morphine side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Opioid medicine can slow or stop your breathing, and death may occur. A person caring for you should give naloxone and/or seek emergency medical attention if you have slow breathing with long pauses, blue colored lips, or if you are hard to wake up.

Morphine may cause serious side effects. Call your doctor at once if you have:

• slow heart rate, sighing, shallow breathing, breathing that stops;

• extreme drowsiness, feeling like you might pass out;

• flushing (sudden warmth, redness, or tingly feeling);

• a seizure;

• high levels of serotonin in the body--agitation, hallucinations, fever, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, diarrhea; or

• low cortisol levels-- nausea, vomiting, loss of appetite, dizziness, worsening tiredness or weakness.

Serious breathing problems may be more likely in older adults and people who are debilitated or have wasting syndrome or chronic breathing disorders.

Common side effects of morphine may include:

• breathing problems;

• drowsiness, dizziness;

• constipation, nausea, vomiting;

• sweating; or

• numbness, tingling, or cold feeling in your hands and feet.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Related/similar drugs

Warnings

MISUSE OF OPIOID MEDICINE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH. Keep morphine where others cannot get to it.

Using opioid medicine during pregnancy may cause life-threatening withdrawal symptoms in the newborn.

Fatal side effects may occur if you also drink alcohol or use other drugs that cause drowsiness or slow breathing.

Before taking this medicine

You should not use this medicine if you have ever had an allergic reaction to morphine or other opioid medicines, or if you have:

• severe asthma or breathing problems;

• a stomach or bowel obstruction (including paralytic ileus); or

• if you have taken an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, or tranylcypromine.

Tell your doctor if you have ever had:

• breathing problems, sleep apnea (breathing that stops during sleep);

• a head injury, brain tumor, or seizures;

• a drug or alcohol addiction, or mental illness;

• urination problems;

• liver or kidney disease; or

• pancreatitis.

If you use opioid medicine during pregnancy, your baby could be born with life-threatening withdrawal symptoms, and may need medical treatment for several weeks.

Ask a doctor before using opioid medicine if you are breastfeeding. Tell your doctor if you notice severe drowsiness or slow breathing in the nursing baby.

How is morphine injection given?

Follow the directions on your prescription label and read all medication guides or instruction sheets. Never use morphine in larger amounts, or for longer than prescribed. Tell your doctor if you feel an increased urge to use more of morphine.

Never share opioid medicine with another person, especially someone with a history of drug addiction. MISUSE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH. Keep the medicine where others cannot get to it. Selling or giving away this medicine is against the law.

Morphine is injected into a muscle or a vein. Morphine injection is sometimes given with an infusion pump that controls your dosing.

You may have withdrawal symptoms if you stop using morphine suddenly. Ask your doctor before stopping the medicine.

Store at room temperature away from moisture and heat. Keep the auto-injector in its original container until you are ready to use it.

Keep your medicine in a place where no one can use it improperly.

Do not keep leftover medicine. Just one dose can cause death in someone using it accidentally or improperly. Ask your pharmacist about a drug take-back program, or flush the unused medicine down the toilet.

What happens if I miss a dose?

Because you will receive morphine in a hospital or with a controlled infusion pump, you are not likely to miss a dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An opioid overdose can be fatal, especially in a child or other person using the medicine without a prescription. Overdose symptoms may include severe drowsiness, pinpoint pupils, slow breathing, or no breathing.

Your doctor may recommend you get naloxone (a medicine to reverse an opioid overdose) and keep it with you at all times. A person caring for you can give the naloxone if you stop breathing or don't wake up. Your caregiver must still get emergency medical help and may need to perform CPR (cardiopulmonary resuscitation) on you while waiting for help to arrive.

Anyone can buy naloxone from a pharmacy or local health department. Make sure any person caring for you knows where you keep naloxone and how to use it.

What should I avoid while using morphine?

Do not drink alcohol. Dangerous side effects or death could occur.

Avoid driving or hazardous activity until you know how morphine will affect you. Dizziness or drowsiness can cause falls, accidents, or severe injuries.

What other drugs will affect morphine?

Many other drugs can be dangerous when used with opioid medicine. Tell your doctor if you also use:

• other opioid medicines;

• a benzodiazepine sedative like Valium, Klonopin, or Xanax;

• sleep medicine, muscle relaxers, or other drugs that make you drowsy; or

• drugs that affect serotonin, such as antidepressants, stimulants, or medicine for migraines or Parkinson's disease.

This list is not complete. Many drugs may affect morphine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.

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Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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