An opioid painkiller
Dihydrocodeine
A moderate-strength opioid painkiller used for pain that is not controlled by ordinary painkillers; it can cause drowsiness, constipation and dependence.
What is Dihydrocodeine?
Dihydrocodeine is a moderate-strength opioid painkiller used when simpler painkillers such as paracetamol or ibuprofen are not enough. It can cause constipation, drowsiness and, with regular use, dependence, so it is generally used at the lowest effective level for the shortest sensible time. It should not be combined with alcohol or other sedating medicines.
Education and reference only. This is a plain-language guide to Dihydrocodeine — 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
Dihydrocodeine is an opioid analgesic used in the UK for moderate to moderately severe pain that has not settled with non-opioid painkillers such as paracetamol or anti-inflammatories. It is a step up from codeine-type painkillers and is available as ordinary tablets, modified-release ('Continus') tablets for longer-lasting cover, and an oral solution. Like other opioids it relieves pain but does not treat the underlying cause, and it carries the recognised opioid risks of tolerance, dependence and side effects, so it is usually intended for short courses or carefully reviewed longer-term use.
How it works
Dihydrocodeine acts on opioid receptors in the brain and spinal cord, the body's own pain-control system. By switching on these receptors it dampens the pain signals travelling to the brain and changes how pain is perceived, so pain feels less intense. The same action on opioid receptors elsewhere in the body explains many of its side effects, such as constipation, drowsiness and slowed breathing at higher exposure.
Company & origin
Originated / developed by: Originally developed in Germany in the early twentieth century..
Dihydrocodeine was first synthesised in Germany in the 1910s and has long been used as a moderate-strength opioid analgesic in the UK.
Practical use
How to take Dihydrocodeine
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it exactly as prescribed, for pain that ordinary painkillers have not controlled, and try to use the smallest amount that keeps the pain manageable.
- Expect possible constipation and drowsiness; ask your pharmacist about a laxative, and do not drive or operate machinery if you feel sleepy or slowed.
- Do not drink alcohol or take other sedating medicines (such as sleeping tablets or other strong painkillers) alongside it.
- Do not stop suddenly after taking it regularly for a while — speak to your prescriber, who will reduce it gradually to avoid withdrawal.
- Swallow modified-release ('Continus') tablets whole and do not crush or chew them, as this can release the opioid too quickly.
- Remember UK drug-driving law: it is an offence to drive while impaired, so do not drive if you feel affected even when taking it as prescribed.
Weighing it up
Advantages & disadvantages of Dihydrocodeine
Advantages
- Effective for moderate pain that simpler painkillers cannot control.
- A familiar, well-understood UK option available in immediate-release and longer-acting forms.
- Can be combined with paracetamol for added pain relief without overlapping opioid risk.
Disadvantages
- Commonly causes constipation that often persists and may need a laxative.
- Causes drowsiness and can impair driving and concentration.
- Carries a real risk of tolerance and dependence with regular use, so it should not be stopped abruptly.
- Dangerous if combined with alcohol or other sedatives because of additive drowsiness and slowed breathing.
Practical use
Good to know
It is an opioid, so it commonly causes constipation (which often does not wear off and may need a laxative) and can make you drowsy. With regular use the body becomes used to it, so it should not be stopped suddenly after a longer course — the dose is reduced gradually to avoid withdrawal. Do not drink alcohol or take other sedating medicines with it, as the combined drowsiness and slowed breathing can be dangerous. It can affect your ability to drive: under UK drug-driving law it is an offence to drive if your driving is impaired, though you may drive if you are taking it as prescribed and are not impaired.
Who should not take it / use with caution
- People with significant breathing problems or acute severe asthma, where opioids can dangerously slow breathing.
- People with a history of opioid dependence or current alcohol or sedative misuse need careful assessment first.
- Used with particular caution in older or frail people, and in those with significant liver or kidney impairment, head injury or raised pressure in the head, an enlarged prostate, or in pregnancy and breastfeeding.
Monitoring
- Review of how well pain is controlled and whether the opioid is still needed.
- Watching for excessive drowsiness, constipation and any signs of tolerance or dependence.
- Plan for gradual reduction rather than abrupt stopping after regular use.
Side effects
- Constipation, which is common and often persists.
- Drowsiness, dizziness, nausea and vomiting, and dry mouth.
- Confusion or low mood, and feeling lightheaded on standing.
- Serious but less common: slowed or shallow breathing, particularly with too much or alongside other sedatives — this needs urgent help.
Key interactions
- Alcohol and other sedatives (sleeping tablets, benzodiazepines, gabapentin/pregabalin, other opioids) — additive drowsiness and dangerous breathing depression.
- Other medicines that cause constipation or drowsiness add to those effects.
- Tell your prescriber and pharmacist about all your medicines, including those bought over the counter.
Available as: Available as tablets, modified-release tablets and an oral solution.
Answers
Dihydrocodeine: frequently asked questions
Is dihydrocodeine addictive?
It is an opioid, so regular use can lead to tolerance and dependence. Using it at the lowest effective level for the shortest sensible time, and reducing gradually rather than stopping suddenly, lowers this risk.
Can I drink alcohol with it?
No. Alcohol adds to the drowsiness and slowed breathing that opioids cause, which can be dangerous. Avoid alcohol while taking it.
Why does it make me constipated?
Opioids slow the gut, and this effect often does not wear off. A laxative is frequently needed; your pharmacist can advise.
Can I drive while taking dihydrocodeine?
Under UK drug-driving law it is an offence to drive if you are impaired. You may drive if you are taking it as prescribed and are not affected, but you must not drive if you feel drowsy or slowed.
Can I stop taking it whenever I want?
If you have taken it regularly, stopping suddenly can cause withdrawal. Speak to your prescriber, who will usually reduce it gradually.
The wider class
About Opioid analgesics
Dihydrocodeine belongs to the opioid analgesics class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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