Morphine

What is morphine?

Morphine is a strong, prescription-only opioid painkiller used to treat severe pain, commonly known by brand names like MST, Zomorph, Sevredol, Morphgesic, MXL, and Oramorph. It’s usually prescribed when milder painkillers (like paracetamol or ibuprofen) are no longer effective. Because of its addiction risk, morphine is a controlled drug and must be taken exactly as prescribed[1]. 

What is morphine used to treat?

Morphine is prescribed for[1]: 

• Severe pain after surgery or injury 

• Cancer pain 

• Heart attack pain 

• Chronic pain when other treatments fail 

• Breathlessness in advanced conditions (e.g. lung disease, heart failure) 

How does morphine work?

Morphine blocks pain signals from reaching the brain by binding to opioid receptors in the central nervous system. It not only reduces pain but can also change how you feel emotionally about it[1].  

Who can take morphine?

Morphine can be used by adults and children (with medical supervision) with acute or chronic severe pain, however young children and older people are more likely to experience side effects[1]. 

Use morphine with caution if you[1]: 

• Are elderly or a child 

• Have breathing issues, liver, kidney or adrenal gland problems, or a history of addiction 

• Have low blood pressure 

• Have an enlarged prostate 

• Have an underactive thyroid 

• Have a head injury 

• Have a condition causing fits or seizures 

• Are pregnant or breastfeeding (only if clearly needed) 

• Are allergic to morphine 

Newborns exposed to morphine near delivery may suffer severe withdrawal (symptoms include tremors, seizures, and vomiting), and would require at least 4 weeks of hospital monitoring. 

Please tell your doctor or pharmacist about any conditions you may have or medication you take before you start treatment, and always follow the instructions in the Patient Information Leaflet[2].  

What is the typical dose of morphine?

Morphine comes as[1]: 

• 10mg, 20mg, or 50mg standard tablets 

• 5mg, 10mg, 15mg, 30mg, 60mg, 100mg, or 200mg slow-release (12 or 24 hours) tablets  

• 10mg, 30mg, 60mg, 90mg, 100mg, 120mg, 150mg, or 200mg slow-release capsules 

• 20mg, 30mg, 60mg, 100mg, or 200mg granules to mix in water to drink 

• a liquid you swallow containing 10mg of morphine per 5ml dose 

• an injection, usually given in hospital 

Never crush, chew, or split slow-release tablets/capsules – this can cause fatal overdose. 

Your dosage will depend on pain severity, type of morphine (e.g. fast-acting or slow-release), and your age, weight, and organ function. Your doctor will start with the lowest effective dose and adjust if needed[1]. 

How do you take morphine?

You should swallow slow-release morphine tablets and capsules whole with water. You can choose to take morphine, in any of its forms, at any time of day, but you should try to take it at the exact same time every day and space your doses evenly. You’ll usually have to take[1]: 

• Standard tablets: 4 to 6 times a day 

• Slow-releases granules, tablets, and capsules: 1 to 2 times a day 

• Liquid: 4 to 6 times a day 

• Injections: 4 to 6 times a day (sometimes in a pump you can control yourself) 

Can you stop taking morphine?

Yes – but don’t stop suddenly. Stopping suddenly can cause severe withdrawal  (sweating, shaking, anxiety, and pain). Your doctor will guide you through a gradual reduction[1]. 

What do you do if you take too much morphine?

An overdose is dangerous – call 999 or go to A&E immediately. Symptoms of overdose include[1]: 

• Extreme sleepiness 

• Slow or shallow breathing 

• Loss of consciousness 

What to do if you forget a dose of morphine?

If you miss a dose of morphine and it’s almost time for your next dose, skip the missed one. Never double up to make up for a mixed dose, but if you’re unsure what to do, check with your doctor or pharmacist[1]. . 

Medicines you can and can’t take with morphine

You should avoid taking morphine with[1]: 

• Other opioids 

• Sleeping pills or sedatives 

• Alcohol 

• Some antidepressants or antipsychotics 

Mixing with alcohol, sleeping pills, or benzodiazepines (e.g., diazepam) is a leading cause of fatal overdose. 

Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[2]. 

What are the side effects of morphine?

The most common side effects of morphine include[1]: 

• Constipation (in 90% of people) 

• Nausea 

• Sleepiness 

• Dizziness 

Speak to your doctor or pharmacist for help with how to manage these common side effects. 

The rarer, but more serious side effects of morphine include confusion, and addiction or dependence. Morphine can also cause fatal breathing problems, especially in the elderly, those with lung disease/sleep apnoea, or when mixed with alcohol/sedatives[1]. 

Your doctor may prescribe laxatives or anti-sickness tablets to help with common side effects. 

You should contact your GP if you experience any of these symptoms. In rare cases, the medicine may cause a serious allergic reaction (anaphylaxis). You should call 999 or visit A&E immediately if you believe this is happening[1]. 

Symptoms of anaphylaxis include:

• Difficulty breathing

• Tightness in throat and chest

• Swelling of the tongue or throat

• Feeling faint or dizzy

• Blue/grey skin or lips

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice. 

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[2]. 

Frequently asked questions about morphine

Will I get addicted to morphine? 
Possibly. Physical dependence develops within weeks. You should never increase your dose without medical supervision[1]. 

Can I drive while taking morphine? 
Only if you're alert and not drowsy. Morphine can affect your ability to drive safely. It is illegal to drive if impaired. You should inform the DVLA if you are using morphine long-term[1]. 

Can I drink alcohol with morphine? 
It’s best avoided – alcohol increases the risk of drowsiness and breathing problems[1]. 

Is morphine safe for long-term use? 
Yes, if monitored closely by your doctor with regular reviews[1]. 

For the official NHS guide for morphine, visit their website.