2. Key facts
Morphine works by blocking pain signals from travelling along the nerves to the brain.
The most common side effects of morphine are constipation, feeling sick and sleepiness.
It’s possible to become addicted to morphine, but this is rare if you’re taking it to relieve pain and your doctor is reviewing your treatment regularly.
It may be best not to drink alcohol while taking morphine as you’re more likely to get side effects like feeling sleepy.
3. Who can and cannot take morphine
Morphine can be taken by children and adults of all ages. However babies, young children and older people are more likely to get side effects.
Morphine is not suitable for some people. Tell your doctor before starting the medicine if you:
have ever had an allergic reaction to morphine or any other medicine
have breathing difficulties or a lung problem
have an addiction to alcohol
have a condition that causes fits or seizures
have a head injury
have low thyroid levels
have adrenal gland problems
have kidney or liver problems
have an enlarged prostate
have low blood pressure
have myasthenia gravis (a rare illness that causes muscle weakness)
are trying to get pregnant, are already pregnant or if you’re breastfeeding – morphine is usually not recommended