Dihydrocodeine is a prescription-only opioid painkiller used in the UK to treat moderate to severe pain. It’s often prescribed after surgery, following an injury, or for long-term pain when weaker painkillers like paracetamol or ibuprofen haven’t worked.
This guide explains what dihydrocodeine is, how it works in the body, and what to check before taking it.
Dihydrocodeine is an opioid analgesic that relieves pain by acting on the central nervous system. It’s a semi-synthetic medicine, meaning it’s made by chemically altering codeine, a naturally occurring compound found in the opium poppy.
In plain terms, dihydrocodeine dulls the way your brain and spinal cord process pain signals. It doesn’t remove the cause of pain, it changes how your body perceives it.
It’s available in a few forms:
According to the NHS, dihydrocodeine is only available with a prescription, and it’s also combined with paracetamol in a medicine called co-dydramol.
Dihydrocodeine sits in the same drug family as codeine, tramadol, and morphine, but it isn’t automatically “better” or “stronger” for every situation. The NHS explains that dihydrocodeine works in a similar way to many other opioids, though it may cause fewer breathing problems for some people. Choosing between opioids usually comes down to the type of pain, your medical history, and how you’ve responded to other painkillers before.
Here’s a quick comparison to put dihydrocodeine in context:
| Feature | Dihydrocodeine | Codeine |
| Type | Semi-synthetic opioid | Naturally occurring opiate |
| Typical use | Moderate to severe pain | Mild to moderate pain |
| UK controlled drug class | Class B (Class A if prepared for injection) | Class B (Class A if prepared for injection) |
| Relative strength | Generally considered somewhat more potent | Baseline reference opioid |
| Common combination medicine | Co-dydramol (with paracetamol) | Co-codamol (with paracetamol) |
Potency comparisons between opioids vary depending on the study and how the drug is taken (orally versus by injection), so these figures should be treated as a general guide rather than an exact rule.
Dihydrocodeine is mainly used to manage pain that’s too strong for standard over-the-counter painkillers, but not severe enough to need a stronger opioid like morphine.
The NHS states that dihydrocodeine treats moderate to severe pain, such as pain following an operation or a serious injury. It’s also used for ongoing pain when paracetamol, ibuprofen, or aspirin haven’t given enough relief.
A GP or hospital doctor might prescribe dihydrocodeine for:
Doctors usually start with the lowest effective dose and review treatment regularly, particularly for longer courses.
Beyond pain relief, dihydrocodeine has antitussive (cough-suppressing) properties and has historically been used to ease breathlessness in certain clinical situations. These uses are less common today and are only given under close medical supervision, since the same opioid action that suppresses cough can also slow breathing.
Dihydrocodeine works by binding to opioid receptors in the brain and spinal cord, which changes how pain signals are sent and interpreted.
Once absorbed, dihydrocodeine attaches to opioid receptors that form part of the central nervous system’s pain regulating pathways. This receptor activity is the core mechanism behind most opioid painkillers, including codeine and morphine.
By binding to these receptors, dihydrocodeine interferes with the transmission of pain signals along nerve pathways. The result is that pain feels less intense, even though the underlying cause hasn’t changed. The NHS confirms that dihydrocodeine works by blocking pain signals from the central nervous system and the brain.
Opioid receptors aren’t only involved in pain. They also sit in areas of the brainstem that control breathing rate and the cough reflex. This is why dihydrocodeine can suppress coughing, and why higher doses carry a risk of slowed or shallow breathing (respiratory depression), especially when combined with alcohol or other sedating medicines.
Before starting dihydrocodeine, it’s worth understanding who needs extra caution, what interacts with it, and how dependence can develop.
Your doctor will want to know your full medical history before prescribing dihydrocodeine. Extra caution is generally needed if you have:
Pregnant or breastfeeding women should always speak to a doctor first, as opioids can affect a baby.
Alcohol increases the sedative effect of dihydrocodeine and raises the risk of dangerous breathing problems, so it’s best avoided while taking this medicine. The NHS advises against driving, cycling, or operating machinery if dihydrocodeine makes you feel dizzy, drowsy, clumsy, or unable to concentrate, even if this only happens occasionally.
It’s also important to tell your pharmacist about any other medicines you take, including over-the-counter products, since combinations with other sedatives (such as sleeping tablets or certain antidepressants) can increase risk.
Like other opioids, dihydrocodeine can lead to tolerance (needing more for the same effect) and physical dependence if used regularly over time. This is why dihydrocodeine is classed as a Class B controlled drug in the UK, becoming Class A if prepared for injection.
If you’ve taken it for more than a few weeks, your treatment plan should include guidance on how and when to reduce or stop the dose, rather than stopping suddenly.
Most people who take dihydrocodeine experience mild, manageable side effects, but a small number may have more serious reactions that need urgent attention.
According to the NHS, the most common side effects include:
| Side effect | What may help |
| Feeling or being sick | Take with food; small sips of water if vomiting |
| Drowsiness | Avoid driving until you know how it affects you |
| Constipation | Drink fluids and eat fibre-rich foods |
| Dizziness or vertigo | Stand up slowly; sit or lie down if it happens |
| Dry mouth | Sugar-free gum or sweets |
| Headache | Rest, fluids, and avoiding alcohol |
Most of these settle down within a few days to two weeks as your body adjusts to the medicine.
Serious side effects are uncommon, affecting fewer than 1 in 100 people, but they need prompt medical attention. These include:
Call 111 or go to A&E if someone’s breathing becomes very slow, shallow, or stops, or if their lips or fingertips turn blue. Do not drive yourself to hospital if you’re experiencing these symptoms.
Using dihydrocodeine safely means sticking to the prescribed dose, never stopping abruptly after long-term use, and knowing when to speak to a doctor.
Always take dihydrocodeine exactly as your doctor or the patient information leaflet advises. Taking more than prescribed doesn’t relieve pain more effectively , it simply increases the risk of side effects, including dangerous breathing problems.
If you’ve been taking dihydrocodeine regularly for more than a few weeks, stopping suddenly can trigger withdrawal symptoms such as sweating, anxiety, shaking, and nausea. Your doctor will usually recommend gradually reducing the dose instead.
If dihydrocodeine isn’t managing your pain well, don’t simply take extra tablets. Book a review with your GP, who can assess whether the dose, formulation, or medicine itself needs to change.
This article is for general information only and is not a substitute for professional medical advice. Always follow the guidance of your doctor or pharmacist, and read the patient information leaflet supplied with your medicine. For full prescribing details, see the NHS dihydrocodeine medicines guide.
Yes, but usually only short-term unless a doctor is supervising.
If it’s needed for more than a few weeks, doctors usually plan how to reduce or stop it safely because of tolerance and dependence risk.nhs+1
Yes, with paracetamol , but only if a pharmacist or doctor says it’s okay.
Dihydrocodeine is often combined with paracetamol in co-dydramol, but combining it with other painkillers or sedating medicines can increase side effects.nhs+1
Yes, generally it’s considered somewhat stronger than codeine.
But “stronger” doesn’t always mean “better”; the right painkiller depends on your health, pain type, and how you respond to medicine.
