Morphine and opioids
The reference strong opioid for severe pain, such as after major surgery, injury or in advanced cancer; highly effective but sedating, constipating and able to slow breathing.
- Generic name
- Morphine and opioids
- Active ingredient
- Morphine and opioids (variants: morphine sulfate, morphine hydrochloride)
- Product type
- Small-molecule medicine
- Drug class
- Opioids
- Brand names
- UK Oramorph, MST Continus, Sevredol, Zomorph · US MS Contin, Kadian
- Routes
- Oral, Intravenous, Subcutaneous, Intramuscular
- Dosage forms
- Solution, Tablet, Extended-release (modified-release) tablet, Capsule, Injection
- Forms
- Immediate-release oral liquid and tablets, 12-hourly modified-release tablets, injections into vein, muscle or under the skin, patient-controlled pumps, patches (fentanyl, buprenorphine)
- Onset and duration
- Intravenous within minutes; oral 30-60 minutes; modified-release over hours.
- Terminology
- RxNorm RxCUI 7052 · ATC N02AA01 · FDA EPC Opioid Agonist [EPC]
- Monitoring
- Sedation score and respiratory rate in hospital; regular review of benefit, dose and side effects at home.
Availability by country
Legal status differs between countries and can change; each row cites the document it was taken from and applies only to the country named.
What it is used for
- Severe acute pain: heart attack, fractures, after major surgery, sickle cell crises
- Cancer pain and pain at the end of life
- Breathlessness in advanced heart and lung disease and in palliative care
- Weaker relatives (codeine, tramadol) for moderate pain; long-term use for chronic non-cancer pain is now discouraged because harms outweigh benefits
How it works in the body
Binds mu-opioid receptors on nerve cells in the spinal cord, brainstem and brain, the same receptors used by the body's own endorphins. This closes the gate on pain signals entering the spinal cord, dampens the emotional response to pain in the brain and, unwantedly, slows the breathing centre in the brainstem, slows the gut and triggers nausea and euphoria.
Common side effects
- Constipation (almost universal, needs a laxative from the start)
- Nausea, drowsiness, itching, dry mouth, small pupils
Serious: seek help
- Respiratory depression and death in overdose, or when combined with alcohol, benzodiazepines or gabapentinoids; reversed by naloxone
- Tolerance, physical dependence and addiction with continued use
- Falls and confusion in the elderly; hormone suppression and immune effects long term
- Opioid-induced hyperalgesia: pain becoming worse with escalating doses
Cautions and interactions
- Controlled drug; start low, review early, plan the stop
- Reduce doses in kidney failure (morphine metabolites accumulate), liver disease and the elderly
- Never crush or chew modified-release forms
- Do not drive while drowsy or after dose changes
Interactions
Check interactions
Taking Morphine and opioids with other medicines? Add them to the checker to see what the official sources say about each pair: the mechanism, general management and monitoring, never a bare "safe".
Interactions documented in the official sources cited on each card. The list covers the medicines represented on this site and is not exhaustive; how the interaction data is compiled.
No pair records for this medicine are in the sources currently represented by Anatomy Nexus. Absence from this list does not mean no interaction exists.
Same-class and related medicines
Same class: Opioids
Medicines that share the class of Morphine and opioids. They are separate medicines with their own licences, doses and interactions, not alternative names for Morphine and opioids.
Related medicines
Medicines often discussed alongside Morphine and opioids: used together, compared with it, or acting on the same problem by a different route.