Generic name: morphine (oral) [ MOR-feen ]
Brand names: Kadian, MS Contin
Drug class: Opioids (narcotic analgesics)

Medically reviewed by Sanjai Sinha, MD. Last updated on Jul 12, 2021.

What is morphine?

Morphine is an opioid medication. An opioid is sometimes called a narcotic. Morphine works by blocking pain signals from travelling along the nerves to the brain.

Morphine is used to treat moderate to severe pain. The extended-release form of morphine is for around-the-clock treatment of pain. Short-acting formulations are taken as needed for pain.

Extended-release morphine is not for use on an as-needed basis for pain.

Warnings

You should not take morphine if you have severe asthma or breathing problems, a blockage in your stomach or intestines, or a bowel obstruction called paralytic ileus.

Morphine can slow or stop your breathing, and may be habit-forming MISUSE OF OPIOID MEDICINE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH, , especially in a child or other person using the medicine without a prescription. Keep the medication in a place where others cannot get to it.

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

Fatal side effects can occur if you use morphine with alcohol, or with other drugs that cause drowsiness or slow your breathing.

Before taking this medicine

You should not take this medicine if you have ever had an allergic reaction to morphine or other narcotic 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.

To make sure morphine is safe for you, tell your doctor if you have ever had:

• breathing problems, sleep apnea (breathing 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
• problems with your gallbladder, pancreas, or thyroid.

If you use opioid medicine while you are pregnant, your baby could become dependent on the drug. This can cause life-threatening withdrawal symptoms in the baby after it is born. Babies born dependent on opioids 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 should I use morphine?

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

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.

Stop taking all other around-the-clock narcotic pain medications when you start taking morphine.

Swallow the capsule or tablet whole to avoid exposure to a potentially fatal overdose. Do not crush, chew, break, open, or dissolve.

Measure liquid medicine with the supplied syringe or a dose-measuring device (not a kitchen spoon).

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

Never crush a pill to inhale the powder or inject it into your vein. This could result in death.

Store at room temperature, away from heat, moisture, and light. Keep track of your medicine. You should be aware if anyone is using it improperly or without a prescription.

Do not keep leftover opioid medication. Just one dose can cause death in someone using this medicine accidentally or improperly. Ask your pharmacist where to locate a drug take-back disposal program. If there is no take-back program, flush the unused medicine down the toilet.

What happens if I miss a dose?

Since morphine is used for pain, you are not likely to miss a dose. If you do miss a dose, take the medicine as soon as you remember. Then take your next dose as follows:

• If you take morphine 1 time per day: Take your next dose 24 hours after taking the missed dose.
• If you take morphine 2 times per day: Take your next dose 12 hours after taking the missed dose.
• If you take morphine 3 times per day: Take your next dose 8 hours after taking the missed dose.

Do not take two doses at one time. Do not take more than your prescribed dose in a 24-hour period.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose can be fatal, especially in a child or person using opioid 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.

Morphine side effects

Get emergency medical help if you have signs of an allergic reaction to morphine: 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 seek emergency medical attention if you have slow breathing with long pauses, blue colored lips, or if you are hard to wake up.

Call your doctor at once if you have:

• slow heart rate, sighing, weak or shallow breathing, breathing that stops;
• chest pain, fast or pounding heartbeats;
• extreme drowsiness, feeling like you might pass out;
• serotonin syndrome – 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 morphine side effects may include:

• drowsiness, dizziness, tiredness;
• constipation, stomach pain, nausea, vomiting;
• sweating; or
• feelings of extreme happiness or sadness.

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.