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  1. About dosulepin
  2. Key facts
  3. Who can and can't take dosulepin
  4. How and when to take it
  5. Side effects
  6. How to cope with side effects
  7. Pregnancy and breastfeeding
  8. Cautions with other medicines
  9. Common questions

1. About dosulepin

Dosulepin is an antidepressant medicine. It's used to treat depression.

It's also occasionally used for some types of nerve pain, such as fibromyalgia, and to prevent migraines.

Dosulepin is available on prescription – usually only if you're already taking it and haven't had any serious side effects.

It comes as capsules and tablets.

2. Key facts

  • Dosulepin was commonly used as an antidepressant in the past. But these days doctors don't write new prescriptions for it unless it has been recommended by a specialist because of concerns about side effects.
  • If you're already taking dosulepin, your doctor will want to consider whether it's still the best treatment option for you. They'll only continue to prescribe dosulepin if a consultant or another specialist agrees with this decision.
  • Common side effects include constipation, feeling dizzy, a dry mouth, feeling sleepy, difficulty peeing, or headaches.
  • Dosulepin can cause extra side effects if you stop taking it suddenly. Talk to your doctor if you're thinking of stopping taking dosulepin.
  • Dosulepin is also known as dothiepin or by the brand name Prothiaden.

3. Who can and can't take dosulepin

Dosulepin is normally only prescribed if you're already taking it and haven't had any serious side effects.

If you haven't had dosulepin before, your doctor won't start you on it because of the risk of serious side effects. But occasionally it may still be the best choice of treatment for you.

If other treatments haven't helped you, your doctor may refer you to a specialist (such as a psychiatrist or pain consultant).

If the specialist thinks it is the best medicine for you, they may start you on dosulepin.

Most adults (aged over 18 years) can take dosulepin. But dosulepin isn't suitable, or the best option, for some people.

Check with your doctor if you:

  • have had an allergic reaction to dosulepin or any other medicine in the past
  • have a heart problem – dosulepin can make some heart problems worse
  • have a rare illness called porphyria
  • have liver or kidney problems
  • have epilepsy or are having electroconvulsive treatment – dosulepin may increase your risk of having a seizure
  • have an eye problem called glaucoma – dosulepin can increase the pressure in your eye
  • have thoughts about harming yourself or ending your life
  • are trying to become pregnant, are already pregnant or are breastfeeding

If you have diabetes, dosulepin may change your blood sugar level. For the first few weeks, check your blood sugar more often and talk to your doctor if it's too high or low.

4. How and when to take it

It's usual to take dosulepin once a day before bedtime. This is because it can make you feel sleepy.

If you're still feeling drowsy the next day, try taking it earlier in the evening.

Sometimes, if you're just starting treatment, your doctor may tell you to take a lower dose 2 or 3 times a day until you get used to the medicine. This will reduce the chance of side effects while you get used to the medicine.

Dosulepin doesn't usually upset your stomach, so you can take it with or without food.

Swallow the tablet or capsule whole with a drink of water. Do not chew it, as it tastes bitter.


Dosulepin comes in 2 different strengths – either 25mg capsules or 75mg tablets.

For depression, the usual dose of dosulepin is 75mg to 150mg a day. Your dose may slowly go up to 225mg a day if your specialist recommends it. The maximum dose for depression is 225mg a day.

For pain relief or preventing migraines, the usual dose is 75mg a day taken in the evening, but this may vary. Your dose may start at 25mg a day and be increased slowly to 75mg a day. The maximum dose of dosulepin for pain or migraine is 150mg a day.

What if I forget to take it?

If you take dosulepin once a day and forget a dose, don't worry. Take your next dose the next day at the usual time.

If you take dosulepin 2 or 3 times a day and forget a dose, take it as soon as you remember unless it's nearly time for your next dose.

Never take 2 doses at the same time to make up for a forgotten one.

If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

What if I take too much?

Urgent advice: Call your doctor now if:

  • you take too much dosulepin

You can get serious side effects within a few hours and may need urgent hospital treatment.

Call your doctor straight away, even if you don't have any symptoms.

5. Side effects

Like all medicines, dosulepin can cause side effects, but many people have no side effects or only minor ones.

Common side effects

Some of the common side effects gradually improve as your body gets used to dosulepin.

Keep taking the medicine, but talk to your doctor or pharmacist if these side effects bother you or don't go away:

  • constipation
  • dizziness
  • a dry mouth
  • feeling sleepy, tired or weak
  • difficulty peeing
  • headaches

Serious side effects

It happens rarely, but some people have serious side effects after taking dosulepin. In particular, there's an increased risk of heart problems.

Call a doctor now if you get:

  • a fast or irregular heartbeat
  • yellow skin, or the whites of your eyes go yellow – these can be signs of a liver problem
  • constant headaches, long-lasting confusion or weakness, or frequent muscle cramps – these can all be signs of low sodium levels in your blood. In severe cases low sodium levels can lead to seizures
  • thoughts about harming yourself or ending your life
  • eye pain, a change in your eyesight, or swelling or redness in or around the eye
  • severe constipation or you're unable to pee and it's causing severe stomach pain

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. If you suspect that you or someone else is having a stroke, phone 999 immediately and ask for an ambulance

Serious allergic reaction

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to dosulepin.

Immediate action required: Call 999 or go to A&E now if:
  • you get a skin rash that may include itchy, red, swollen, blistered or peeling skin
  • you're wheezing
  • you get tightness in the chest or throat
  • you have trouble breathing or talking
  • your mouth, face, lips, tongue or throat start swelling

You could be having a serious allergic reaction and may need immediate treatment in hospital.

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.

Visit Yellow Card for further information.

6. How to cope with side effects

What to do about:

  • 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. Watch a short video on how to treat constipation.
  • dizziness – this is probably due to low blood pressure (hypotension). Drink plenty of water or a non-alcoholic drink. Do not stand up too quickly after sitting or lying down.
  • dry mouth – chew sugar-free gum or sugar-free sweets.
  • feeling sleepy or tired – take dosulepin in the evening and cut down the amount of alcohol you drink. Do not drive or use tools or machinery if you're feeling sleepy. If this doesn't help, talk to your doctor.
  • difficulty peeing – relax when you try to pee. Do not try to force the flow of urine. If you can't go, try again later. Talk to your doctor urgently if you can't pee at all.
  • headaches – make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Talk to your doctor if the headaches last longer than a week or are severe.

7. Pregnancy and breastfeeding

It's important for you and your baby that you stay well during your pregnancy. If you become pregnant while taking dosulepin speak to your doctor. Do not stop taking your medicine unless your doctor tells you to.

Dosulepin has been linked to a very small increased risk of problems for your unborn baby. However if your depression is not treated during pregnancy this can also increase the chance of problems.

You may need to take dosulepin during pregnancy if you need it to remain well. Your doctor can explain the risks and the benefits, and will help you decide which treatment is best for you and your baby.

Dosulepin and breastfeeding

If your doctor or health visitor says your baby is healthy, dosulepin can be used during breastfeeding.

Dosulepin passes into breast milk in very small amounts, and has not been linked with any side effects.

It is important to continue taking dosulepin to keep you well.

Breastfeeding will also benefit both you and your baby.

If you notice that your baby isn't feeding as well as usual, or seems unusually sleepy or restless, or if you have any other concerns about your baby, then talk to your health visitor or doctor as soon as possible

Non-urgent advice: Tell your doctor if you're:

  • trying to get pregnant
  • pregnant
  • breastfeeding

8. Cautions with other medicines

Many medicines and dosulepin can interfere with each other and increase the chances of side effects. In some cases, taking dosulepin with other medicines can cause serious side effects.

Make sure your doctor and pharmacist know what other medicines you are taking. This is important when you start or stop any other medicines, or when you have the dose changed.

Mixing dosulepin with herbal remedies and supplements

Do not take St John's wort, a herbal remedy for depression, while you're taking dosulepin. It'll increase your risk of side effects.

It's not possible to say whether other complementary medicines or herbal remedies are safe to take with dosulepin.

They're not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.

Important: Medicine safety

Tell your doctor or pharmacist if you're taking any other medicines, including herbal medicines, vitamins or supplements.

9. Common questions

How does dosulepin work?

Dosulepin is from a group of antidepressants called tricyclic antidepressants.

For depression, it's thought to work by increasing levels of a chemical called serotonin in the brain. This can improve your mood.

For pain or preventing migraines, dosulepin can change the way your nerves receive pain signals. This can help with some kinds of nerve pain, including fibromyalgia. It can also help prevent migraine attacks.

When will I feel better?

Do not expect to feel better overnight. Some people feel worse during the first few weeks of treatment before they feel better.

It usually takes 4 to 6 weeks for dosulepin to fully work against depression, and 2 to 6 weeks for dosulepin to fully work against pain or migraine.

Talk to your doctor if you're not feeling any better after taking dosulepin for 6 weeks, if you're worried about side effects, or if you're having thoughts of harming yourself.

How will it make me feel?

For depression – dosulepin helps to lift your mood so you feel better. You may notice that you sleep better and get on with people more easily because you're less anxious. Hopefully, you'll take little things that used to worry you in your stride.

Dosulepin won't change your personality or make you feel euphorically happy. It'll simply help you feel like yourself again.

Some people feel a little drowsy with dosulepin, which is why it may be better to take it in the evening.

For pain – taking dosulepin as a painkiller won't change your personality or make you feel any different, although many people say they sleep better while they're taking dosulepin.

How long will I take it for?

For depression – once you're feeling better, it's likely that you'll continue to take dosulepin for several more months.

Most doctors recommend that you take antidepressants for 6 to 12 months after you have stopped feeling depressed. Stopping before then can make depression come back.

But dosulepin is no longer recommended over other antidepressants, and you should talk to your doctor about staying on dosulepin or switching to another medicine to treat depression.

Talk to your doctor about the pros and cons of taking dosulepin, or another antidepressant, for longer than a few months.

It'll depend on how bad your symptoms are, whether it's a one-off problem or one that keeps coming back, how well dosulepin works for you, and whether you have had any bad side effects.

For pain or preventing migraines – some people take dosulepin for many months, or even for years. But dosulepin is no longer recommended over other antidepressants that are used to treat pain, such as amitriptyline.

You should talk to your doctor about staying on dosulepin or switching to another medicine to treat or prevent pain.

Why is dosulepin prescribed less often now?

Dosulepin is not recommended for new patients now. It can be harmful for some people and is very dangerous if you take too much.

It's still sometimes prescribed for people who are already using it who haven't had serious side effects.

If you haven't had it before, it's unlikely to be prescribed for you. A specialist (such as a psychiatrist or a pain consultant) might start you on it if other medicines have not worked and they think it's the best choice for you.

If it's not recommended, should I stop taking it?

Do not stop taking dosulepin without talking to your doctor. You may suffer side effects if you stop taking it suddenly.

If you and your doctor agree that you should stop taking dosulepin, your doctor will probably recommend reducing your dose gradually over several weeks.

If you're switching to another medicine, your doctor will explain how to introduce it slowly.

Can I still get dosulepin if it helps my depression?

If you have been taking dosulepin for a while, your doctor may suggest trying a different medicine instead.

There are now many safer alternative antidepressants to dosulepin that have fewer side effects. It's also possible you'll no longer need to take an antidepressant at all.

But if dosulepin works for you and you haven't had any serious side effects with it, your doctor may still prescribe it for you if a consultant or another health specialist agrees this is still the best treatment option for you.

How does it compare with other antidepressants?

Dosulepin does not work any better or worse than other antidepressants, though sometimes people respond better to one antidepressant than another.

But it's not often prescribed now because there's a greater risk of serious heart problems if you're taking a higher dose.

It may be safer to take a different tricyclic antidepressant, such as amitriptyline or another type of antidepressant.

Talk to your doctor if you aren't feeling any better on dosulepin or you're worried about side effects.

Can I still get dosulepin if it helps my pain?

Dosulepin is sometimes used to treat some types of nerve pain, such as fibromyalgia, or to prevent migraine. But it's not recommended for, or officially approved for, pain relief.

Because of this, your doctor will probably prescribe other medicines. If you're already taking dosulepin, they may suggest switching to something else.

Other possible treatments include:

Finding the most suitable treatment depends on how long you have had the pain, your symptoms, and what medicines have and have not worked for you in the past.

Is it safe to take for a long time?

Dosulepin is safe to take for a long time as long as you're not getting side effects. There don't seem to be any lasting harmful effects from taking it for many months and years.

Is it addictive?

Dosulepin is not addictive, but you may get extra side effects when you stop taking dosulepin, especially if you stop taking it suddenly. These side effects are a reaction to coming off the medicine.

The side effects are usually harmless but unpleasant. They may include headaches, flu-like symptoms, feeling sick, finding it hard to sleep, and feeling restless or anxious.

To help prevent these side effects, your doctor will probably recommend reducing your dose gradually over several weeks.


Do not stop taking dosulepin suddenly, or without talking to your doctor.

Will I gain or lose weight?

Dosulepin can change how hungry you feel. Some people feel more hungry when they're taking it – others feel less hungry. So your weight may change when you first start taking it.

If you start to have problems with your weight while taking dosulepin, talk to your doctor or pharmacist.

Can I drive or ride a bike?

Some people feel sleepy while they're taking dosulepin. It might be best to stop driving and cycling until you know how this medicine makes you feel.

Can I drink alcohol with it?

You can drink alcohol while taking dosulepin, but it may make you feel sleepy. It might be best to stop drinking alcohol until you see how the medicine makes you feel.

The serious side effects of dosulepin can be made worse by binge drinking. If you're drinking alcohol with dosulepin, it's best to cut down the amount you drink.

Is there any food or drink I need to avoid?

You can eat and drink normally while taking dosulepin.

Will it affect my contraception?

Dosulepin does not affect any type of contraception, including the combined pill or emergency contraception.

Will it affect my sex life?

The good effects of dosulepin may, after a while, improve your sex life as your mood lifts and you become interested in life and relationships again.

Some of the possible negative effects include:

  • men having problems with getting an erection and problems ejaculating
  • women having some vaginal bleeding
  • both men and women having breast swelling

Sexual side effects are not common and should pass after the first couple of weeks. If they don't and this is a problem for you, go back to your doctor to see if there's another antidepressant you can try.

If you're a woman and you get vaginal bleeding after the menopause, make an appointment to see your doctor as soon as possible.

Will it affect my fertility?

There's no firm evidence to suggest that taking dosulepin will reduce fertility in either men or women. However, speak to a pharmacist or your doctor before taking it if you're trying to get pregnant.

Will recreational drugs affect it?

Cannabis with dosulepin can make you feel very sleepy, especially if you have just started taking it. Cannabis with dosulepin can also give you a fast heartbeat.

It can be dangerous to take dosulepin with:

  • methadone
  • stimulants like MDMA (ecstasy) or cocaine
  • hallucinogens like LSD
  • novel psychoactive substances (which used to be known as legal highs) like mephedrone

Dosulepin hasn't been properly tested with recreational drugs. Talk to your doctor if you think you might use recreational drugs while taking dosulepin.

Are there other treatments that help with depression?

Antidepressants, including dosulepin, are just one of several approaches to treating depression. Other potential treatments include:

Choosing a treatment that's most suitable for you depends on:

  • how long you have had depression
  • your symptoms
  • whether you have had depression before
  • whether previous treatment has worked
  • how likely you are to stick with your treatment
  • the potential side effects
  • your preferences and priorities

If you're interested in any of these treatments, talk to your doctor.