Like all medicines, dihydrocodeine can cause side effects in some people, but many people have no side effects or only minor ones.
You're more likely to have side effects if you take the higher strengths of dihydrocodeine.
Common side effects
These common side effects of dihydrocodeine happen in more than 1 in 100 people. There are things you can do to help cope with them:
Constipation
Dihydrocodeine slows down your digestion and this can cause constipation. If you become constipated, try to include more high-fibre foods in your diet such as fruits, vegetables and cereals. Try to drink several glasses of water each day. If you can, it may also help to do some gentle exercise.
Ask your doctor about medicine to help prevent or treat constipation caused by dihydrocodeine.
Feeling or being sick (nausea or vomiting)
Take dihydrocodeine with or just after a meal or snack to ease feelings of sickness. If you're being sick, try small frequent sips of water.
This side effect should wear off after a few days. Talk to a doctor about taking an anti-sickness medicine if it carries on for longer.
If you take the combined contraceptive pill or the progestogen-only pill and you're being sick your contraception may not protect you from pregnancy. Check the contraceptive pill packet for advice.
Feeling sleepy
This side effect should wear off within a week or two as your body gets used to dihydrocodeine. Talk to a doctor if it carries on for longer.
Confusion, feeling dizzy and vertigo (a sensation of spinning)
If dihydrocodeine makes you feel dizzy when you stand up, try getting up very slowly or stay sitting down until you feel better. If you begin to feel dizzy, lie down so that you do not faint or fall, then sit until you feel better.
This side effect should wear off within a few days as your body gets used to dihydrocodeine. Talk to a doctor if it carries on for longer.
Dry mouth
Try chewing sugar-free gum or sucking sugar-free sweets. You can also buy or a doctor may prescribe an artificial saliva substitute to keep your mouth moist. This comes as a spray, gel or lozenge and can be bought from a pharmacy.
Headaches
Make sure you rest and drink plenty of fluids. It may be best not to drink alcohol while taking dihydrocodeine as this can make headaches worse. It's safe to take a painkiller such as paracetamol or ibuprofen.
Talk to a doctor if headaches last longer than a week or are severe.
Speak to a doctor or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or does not go away.
Serious side effects
Serious side effects happen in less than 1 in 100 people.
Call a doctor or call 111 now if you:
- get muscle stiffness
- feel dizzy, tired and have low energy – this could be a sign of low blood pressure (hypotension)
Immediate action required: Call 999 if:
- you have had a seizure or fit
- you have difficulty breathing or short shallow breathing
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to dihydrocodeine.
Immediate action required: Call 999 now if:
- your lips, mouth, throat or tongue suddenly become swollen
- you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
- your throat feels tight or you're struggling to swallow
- your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
- you suddenly become very confused, drowsy or dizzy
- someone faints and cannot be woken up
- a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)
You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.
These can be signs of a serious allergic reaction and may need immediate treatment in hospital.
Long-term side effects
Some people with conditions that need long-term pain relief may need to take dihydrocodeine for a long time.
If you need to take it for a long time your body can become used to it (known as tolerance). That means you need higher doses to control your pain over time.
Some people can become more sensitive to pain (hyperalgesia). If this happens, your doctor will reduce your dose gradually to help these symptoms.
It's possible to become addicted to dihydrocodeine. For this reason, your dose will be reviewed to make sure you're only having the amount you need to control your pain.
Your treatment plan may include details of how and when you'll stop dihydrocodeine.
If you're having treatment for cancer pain or other severe pain, your pain control will be carefully monitored. Speak to your doctor if you're worried about tolerance, hyperalgesia or becoming addicted.
Other side effects
These are not all the side effects of dihydrocodeine. For a full list, see the leaflet inside your medicine packet.
You can report any suspected side effect using the Yellow Card safety scheme.