NZ Formulary

Morphine (short acting)

mor-feen

What does it do?

Morphine is used to relieve strong pain.

Before you start

  • Tell your doctor if you have bowel or kidney problems, sleep apnoea, if you have ever had a seizure, or have had a recent head injury.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.

How should you take it?

Take morphine as directed. You can take it with or without food.
Tablet: Take with a glass of water.
Liquid: Measure carefully with an oral syringe or measuring spoon.

What if you forget a dose?

If morphine is taken regularly and it is nearly time for your next dose, skip the missed dose and take your next dose at the usual time. Otherwise, take the missed dose as soon as you remember. Do not take two doses at the same time.

Can you take other medicines?

Some medicines available without a prescription may react with morphine including:

  • sedating antihistamines (e.g. Phenergan®)
  • cough suppressants (e.g. Duro-Tuss®, Benadryl Dry Forte®)

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Slow or shallow breathing, hard to wake up

Seizures

Tell your doctor immediately

Confusion, hallucinations, mood changes

Tummy pain (new or getting worse)

Tell your doctor

Constipation

Take your prescribed laxatives. Tell your doctor

Drowsiness, dizziness

Nausea, vomiting, dry mouth or throat

Itching, flushing, sweating

Strange or uncontrolled movements

Tell your doctor if troublesome

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Morphine ‘short acting’ can be taken regularly or when required. If morphine is not relieving your pain contact your health professional - your dose may need changing.
  • Morphine ‘short acting’ may be used with longer-acting pain relief medicines (e.g. morphine ‘long acting’ or fentanyl patches).
  • Morphine can impair your ability to do tasks such as driving or using machines. Alcohol makes this worse. Discuss your risk with your health professional. (search NZTA - Are you safe to drive?)
  • Morphine may be addictive with long-term use.
  • Long-term use of morphine may cause side effects such as less interest or trouble having sex, or changes in periods. It may also make some types of pain worse. Discuss with your doctor.
  • If you have been taking morphine regularly for a long time, talk to your doctor before stopping.