A strong, long-acting opioid painkiller
Levorphanol
A strong, long-acting opioid painkiller used for severe pain, and a controlled drug.
What is Levorphanol?
Levorphanol is a strong opioid painkiller used for severe pain when weaker painkillers are not enough. It is long-acting, which means it stays in the body for a long time and can build up with repeated doses, so it must be used carefully. Like other strong opioids, its most serious risk is slowed or stopped breathing (respiratory depression), and it can cause drowsiness, constipation, and dependence with longer use. It is a controlled drug used under close medical supervision. It is largely a US product rather than one routinely used in the UK.
Education and reference only. This is a plain-language guide to Levorphanol — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Levorphanol is a strong opioid painkiller, in the same broad family as morphine, used for severe pain that needs a powerful medicine. A key feature is that it is long-acting, so its effects, and its risks, last a long time and it can gradually accumulate in the body when taken repeatedly. It is a controlled drug because of the risk of misuse and dependence, and it is used under close medical supervision. It is largely a US product and is not a routine choice in the UK, where other strong opioids are more commonly used.
How it works
Levorphanol works by acting on opioid receptors in the brain and spinal cord, the body's own pain-control system, to reduce the sensation of pain and the distress it causes. Because it is long-acting, a single dose lasts a long time, but this also means the medicine can build up with repeated dosing before a steady level is reached, increasing the risk of side effects such as drowsiness and slowed breathing. The same action on the brain causes its other effects, including constipation, and over time the body can become tolerant to and dependent on it.
Company & origin
Originated / developed by: Various manufacturers.
A strong, long-acting opioid painkiller used for severe pain; it is a controlled drug and largely a US product rather than a routine UK one.
Practical use
How to take Levorphanol
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it exactly as prescribed and never increase the dose yourself, as it is long-acting and can build up in the body.
- Avoid alcohol and tell your doctor about sedatives or other drowsy medicines, as combining them can dangerously slow breathing.
- Expect constipation and use a laxative if advised, as this is very common with opioids.
- Do not drive or operate machinery if it makes you drowsy.
- Do not stop it suddenly after regular use; your doctor will reduce it gradually to avoid withdrawal.
Weighing it up
Advantages & disadvantages of Levorphanol
Advantages
- Provides strong relief for severe pain when weaker painkillers are not enough.
- Long-acting, so its effect lasts a long time from each dose.
- Acts on the body's own pain-control system.
Disadvantages
- Can dangerously slow or stop breathing, especially with alcohol or other sedating medicines.
- Because it is long-acting, it can build up in the body with repeated dosing.
- Causes drowsiness, constipation, and dependence with longer use, and is a controlled drug.
Practical use
Good to know
The most important thing to understand about levorphanol is that it is a strong, long-acting opioid, so its most serious risk is slowed or even stopped breathing, especially when treatment is started or the dose is increased, and particularly if it is combined with alcohol, sedatives or other medicines that cause drowsiness. Because it is long-acting, it can build up in the body over the first days of treatment, so any increase needs to be cautious and supervised. Drowsiness can affect driving and operating machinery. Constipation is very common and usually needs a laxative, and other effects include nausea, especially at first. With longer use, the body becomes tolerant and physically dependent, so it should not be stopped suddenly. It is a controlled drug that must be stored safely and used only by the person it is prescribed for. Naloxone can reverse an opioid overdose. It is used under close medical supervision.
Who should not take it / use with caution
- People with severe breathing problems or a sudden, severe asthma attack should not use it.
- People who have had a serious allergic reaction to it should not use it.
- It is used with great caution in older or frail people, and those with breathing, liver or kidney problems.
- It is used with care in people with a history of drug or alcohol dependence, and avoided with certain other sedating medicines.
Monitoring
- Watching for drowsiness and slowed breathing, especially when starting or increasing the dose.
- Reviewing pain control and whether the opioid is still needed.
- Checking for constipation and other side effects, and for signs of tolerance or dependence over time.
Side effects
- Drowsiness, dizziness and confusion, especially when starting or increasing the dose.
- Constipation, which is very common, and nausea or vomiting, especially at first.
- Slowed breathing (respiratory depression), which can be serious and is the main danger.
- With longer use, tolerance and physical dependence; rarely, serious allergic reactions.
Key interactions
- Alcohol, sedatives, sleeping tablets and other opioids add to drowsiness and the risk of slowed breathing.
- Some medicines for anxiety, mental health or seizures increase sedation when combined with it.
- Medicines that affect alertness or breathing should be reviewed before it is used together with them.
Available as: Tablets taken by mouth, and a solution for injection.
Answers
Levorphanol: frequently asked questions
What is levorphanol used for?
It is a strong, long-acting opioid painkiller used for severe pain when weaker painkillers are not enough, under close medical supervision.
Why does being long-acting matter?
Because it stays in the body a long time, it can build up with repeated doses over the first days, so any increase must be cautious to avoid drowsiness and slowed breathing.
What is the most serious risk?
Its most serious risk is slowed or stopped breathing, especially when starting or increasing the dose or if combined with alcohol or other sedating medicines.
Will I become dependent on it?
With longer use the body becomes tolerant and physically dependent, so it should not be stopped suddenly; your doctor will reduce it gradually when it is no longer needed.
Can I drink alcohol or drive while taking it?
No to alcohol, as it adds to the risk of slowed breathing, and you should not drive or operate machinery if the medicine makes you drowsy.
The wider class
About Opioid analgesic (strong)
Levorphanol belongs to the opioid analgesic (strong) class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
Browse by body system
Authoritative sources
- BNF
- NICE CKS
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