Like all medicines, dosulepin can cause side effects, but many people have no side effects or only minor ones.
Common side effects
These common side effects of dosulepin happen in more than 1 in 100 people. There are things you can do to help cope with them:
Constipation
Eat more high-fibre foods, such as fresh fruit and vegetables and cereals. Try to have several glasses of water, or other non-alcoholic drinks, every day. If you can, it may also help to do some exercise.
Feeling dizzy
This is probably because of low blood pressure (hypotension). Drink plenty of water or non-alcoholic drinks. Do not stand up too quickly after sitting or lying down.
Dry mouth
Chew sugar-free gum or suck sugar-free sweets.
Feeling sleepy or tired
Take dosulepin in the evening and try to cut down the amount of alcohol you drink. Do not drive or use tools or machinery if you're feeling sleepy. If this does not help, talk to your doctor.
Difficulty peeing
Relax when you try to pee. Do not try to force the flow of urine. If you cannot go, try again later. Talk to your doctor, urgently, if you cannot pee at all.
Headaches
Make sure you rest and drink plenty of fluids. Try not to drink too much alcohol. Talk to your doctor if the headaches last longer than a week or are severe.
Blurred vision
Do not drive, cycle or operate machinery if this happens to you. This may improve as your body gets used to the medicine, but if it does not get better after 1 week, talk to your doctor as they may need to prescribe a different medicine.
If this advice does not help and any of these side effects continue, tell your doctor or pharmacist.
Serious side effects
Serious side effects after taking dosulepin are rare but there are some risks. There is an increased risk of heart problems.
Call your doctor call 111 now if:
- your heart is beating faster or in an irregular way
- the whites of your eyes turn yellow, or your skin turns yellow although this may be less obvious on brown or black skin – this can be a sign of liver problems
- you have constant headaches, long-lasting confusion or weakness, or frequent muscle cramps – these can all be signs of low sodium levels in your blood
- you get eye pain, a change in your eyesight, or swelling or redness in or around the eye
- you have severe constipation or you're unable to pee
Immediate action required: Call 999 or go to A&E if:
- you have thoughts about harming yourself or ending your life
Immediate action required: Call 999 now if you get:
- weakness on one side of your body
- trouble speaking or thinking
- loss of balance, or blurred eyesight
These can be signs of a stroke.
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to dosulepin.
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.
Other side effects
These are not all the side effects of dosulepin. For a full list, see the leaflet inside your medicine packet.
You can report any suspected side effect using the Yellow Card safety scheme.