Sounds like 'mor-feen'

Morphine is used for pain relief. Find out how to take it safely and possible side effects. Morphine is commonly called RA-Morph, m-Eslon SR and Sevredol.

Type of medicine Also called
  • Belongs to a group of medicines known as analgesics (painkillers) 
  • Opioid pain reliever
  • RA-Morph®
  • m-Eslon SR®
  • Sevredol®
  • LA-Morph®
  • Arrow-Morphine LA®

What is morphine?

Morphine is used for the relief of moderate to severe pain such as after an injury, or operation or pain caused by a terminal illness such as cancer. It is usually used when other milder painkillers such as paracetamol or non-steroidal anti-inflammatories (NSAIDs) don’t work well enough.

  • Morphine belongs to a group of medicines called opioid painkillers. They act on your brain and nervous system to reduce pain.
  • Other pain relievers such as paracetamol and NSAIDs (ibuprofen, diclofenac, naproxen) may also be used with morphine.
  • Morphine is not very effective for nerve pain.
  • In New Zealand morphine is available as capsules, tablets, in a liquid form and as an injection.
  • Read more about painpain-relief medicationopioid painkillers.


  • The dose of morphine will be different for different people.
  • Always take your morphine exactly as your doctor has told you. Depending on the reason you are taking it, your doctor may advise that you take regular doses or take morphine only when you need it for pain relief. Make sure you know which is right for you.
  • The pharmacy label on your medicine will tell you how much morphine to take, how often to take it, and any special instructions.

My dose is:

Morning Lunch Tea time Night

How to take morphine

  • You can take morphine with or without food.
  • Morphine is available as tablets and capsules. The oral liquid and injections are mostly used in hospital.
  • Some types of morphine are short-acting or immediate release and others are long-acting or slow release.  Ask your pharmacist if you are not sure about the type you are taking.  
 Formulation  How to take it
 Tablets Morphine tablets are available as short-acting or immediate release and long-acting or slow release 

Immediate release tablets
  • Examples are Sevredol® tablets.
  • These are usually taken every 4 to 6 hours.
  • The tablets start working quickly to ease pain.
  • Swallow the tablets with a glass of water. Tablets may be halved.
Long-acting or slow release tablets
  • Examples are Arrow-Morphine LA® or LA-Morph® tablets.
  • The tablets work slowly over several hours to give a constant and more even pain control – these are called 'LA' or long-acting tablets.
  • These are usually taken two times a day (12 hours apart) or once daily (at the same time each day).
  • Swallow the tablets whole – do not break or chew them; otherwise, they may release the medicine too quickly and cause side-effects.
  • Examples are m-Eslon SR
  • The capsules work slowly over several hours to give a constant and more even pain control – these are called 'SR' or slow release capsules.
  • These are usually taken two times a day (12 hours apart) or once daily (at the same time each day).
  • Swallow the capsules whole – do not break or chew them; otherwise, they may release the medicine too quickly and cause side-effects.
  • Limit or avoid drinking alcohol while you are taking morphine. Taking morphine with alcohol can make you more sleepy, drowsy or dizzy.
  • If you forget to take your dose, take it as soon as you remember. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the amount.

Precautions before starting morphine

  • Do you have breathing problems such as asthma, COPD or sleep apnoea?
  • Have you had an accident or a head injury?
  • Do you have low blood pressure or problems with your thyroid?
  • Do you have problems with your bowel such as constipation?
  • Are you pregnant or breastfeeding?
  • Are you taking any other medicines? This includes any medicines you buy without a prescription, such as herbal and complementary medicines.

If so, it’s important that you tell your doctor or pharmacist before you start morphine. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

What are the side effects of morphine?

Like all medicines, morphine can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.


Addiction is an excessive craving. If you are addicted to morphine, it means you are not able to control your use of it. It is unusual for people who are prescribed morphine for a short time or for a terminal illness to become addicted to it.

Some people are more likely to develop addiction than others and seem to be very sensitive to the cravings. You may be at risk for addiction if you have mental health problems such as depression or a history of substance abuse, including alcohol and recreational drugs.

To reduce your risk of addiction, morphine for short-term pain relief should be used for the shortest possible time, at the lowest effective dose, with a plan in place to reduce and withdraw treatment.

Other side effects

Side effects What should I do?
  • Feeling sleepy, dizzy or tired
  • Reduced concentration
  • This is common when starting morphine or after increasing the dose.
  • Be careful when driving or using tools until you know how this medicine affects you.
  • Do not drink alcohol.
  • Feeling sick (nausea) or vomiting
  • This common in the first week to ten days of treatment.
  • Mostly this settles and goes away.
  • Tell your doctor if this is troublesome. You may need an anti-sickness tablet at times.
  • Constipation
  • Constipation is very common. 
  • Ask your doctor to prescribe a laxative; you will need to take it regularly.
  • You may also need to eat more fruit, vegetables, brown bread, bran-based breakfast cereals and drink plenty of water. Read more about how to ease and prevent constipation.
  • Headache, dry mouth 
  • These are quite common when you first start taking morphine and usually go away with time.
  • Tell your doctor if troublesome.
  • Altered vision, skin rash and itching
  • Tell your doctor
  • Breathing difficulties, slow or irregular breathing 
  • Tell your doctor immediately or ring HealthLine 0800 611 116
Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product


Morphine interacts with some other medications and herbal supplements, so check with your doctor or pharmacist before starting morphine or before starting any new medicines. It may interact with medicines available without a prescription such as cough suppressants (such as Benadryl Dry Forte®, Duro-Tuss®) and sedating antihistamines (such as Phenergan®).

Learn more

Medsafe Consumer Information Sheet: Arrow-Morphine LA 
New Zealand Formulary Patient Information: morphine (short acting) morphine (long acting)


  1. Morphine salts New Zealand Formulary

Additional resources for healthcare professionals

LA morph tablet Medsafe, NZ
m-eslon SR capsule Medsafe, NZ
RA-morph oral solution Medsafe, NZ
Sevredol tablet Medsafe, NZ
Strong opioids for pain management in adults in palliative care BPAC, NZ, 2012
When and how to use a syringe driver in palliative care BPAC, NZ, 2012
Safe prescribing of morphine in primary care BPAC, NZ, 2008
Learning sessions HQSC, NZ
Safe use of opioids collaborative newsletter – issue 3 HQSC, NZ, 2016
Safe use of opioids national collaborative national workshop HQSC, NZ, 2016
Palliative care – oral morphine initiation and dose titration guide for opioid naïve patient SafeRx, Waitematā DHB, NZ, 2017

Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 19 Apr 2018