Morphine Sulfate

Medically Reviewed by Dr. Harshi Dhingra, M.D.

Last Reviewed: Dec 08, 2022

Side Effects


Morphine Side Effects

Possible side effects of morphine are listed below. Tell your doctor if these side effects are severe or do not go away in a few days.

  • Drowsiness
  • Stomach pain
  • Headache
  • Dry mouth
  • Mood changes
  • Nervousness
  • Small pupils
  • Difficulties with urination

Less commonly, morphine can cause more serious side effects. Call your healthcare provider immediately or seek emergency medical help if you have the following symptoms:

  • Fever, sweating, shivering, confusion, agitation, hallucinations, fast heartbeat, nausea, vomiting, diarrhea, muscle stiffness, muscle twitching, loss of coordination
  • Weakness, dizziness, nausea, vomiting, loss of appetite
  • Erectile dysfunction (inability to achieve or keep an erection)
  • Irregular menstruation
  • Decreased libido (sexual desire)
  • Extreme drowsiness
  • Seizures
  • Fainting
  • Skin rash, hives, itching
  • Difficulty breathing or swallowing
  • Respiratory depression (slowed breathing)
  • Swelling of the throat, tongue, lips, eyes or face

The above list may not include all the potential adverse effects of morphine. Contact your doctor for medical advice about side effects if they are unusual or severe or do not get better over time. You can also report unusual side effects to the Food and Drug Administration at 1-800-FDA-1088.

Morphine Overdose:  In case of an accidental or intentional overdose of morphine, contact your doctor immediately. You can also call the national poison control center at 1-800-222-1222. If a person cannot be awakened, has trouble breathing, has collapsed, or has had a seizure, call 911.

 Symptoms of a morphine overdose may include difficulty breathing, slowed or stopped breathing, narrowing of the pupils, extreme sleepiness, limp muscles, cold and clammy skin, and unresponsiveness.

 Talk to your doctor about having a rescue medication called naloxone on hand in case of an overdose. Naloxone can reverse the life-threatening effects of an opioid overdose. Make sure you and others in your household know how to recognize the signs of a morphine overdose, how to use naloxone, and what to do until emergency medical help arrives.

Source: FDA