- Duloxetine normally takes 2 to 4 weeks to work. It may take longer if you're taking it for nerve pain.
- Common side effects include feeling sick, a dry mouth, headache, constipation and feeling sleepy. These side effects are usually mild and go away after a couple of weeks.
- If you and your doctor decide to take you off duloxetine, your doctor may recommend reducing your dose gradually to help prevent extra side effects.
- Duloxetine is also called by the brand names Cymbalta and Yentreve.
Duloxetine can be taken by adults aged 18 years and over.
For stress urinary incontenince, duloxetine can only be used by women.
Duloxetine is not suitable for some people. To make sure it's safe for you, tell your doctor if you:
- have had an allergic reaction to duloxetine or any other medicines in the past
- have kidney or liver problems
- have a heart problem
- are taking or have taken other medicines for depression within the last 14 days
- have an eye condition called glaucoma - duloxetine can increase the pressure in your eye
- have or have had fits, manic episodes or bipolar disorder
- bruise easily
- are trying to become pregnant, are already pregnant, or you're breastfeeding
For depression, anxiety and nerve pain, you'll usually take duloxetine once a day.
For urinary incontinence, you'll usually take duloxetine twice a day.
Swallow the capsules whole with a drink of water or juice. Do not chew them.
You can take duloxetine with or without food, but it's best to take it at the same time each day.
How much will I take?
For depression, anxiety and nerve pain, duloxetine comes in 30mg and 60mg capsules.
For stress urinary incontinence, duloxetine comes in 20mg and 40mg capsules.
How much you take will depend on what you're taking it for:
- depression - the starting dose is 60mg a day and can be increased to 120mg a day
- anxiety - the starting dose is 30mg a day and can be increased to 60mg a day
- nerve pain - the starting dose is 60mg a day and can be increased to 60mg twice a day
- stress urinary incontinence - the starting dose is 20mg twice a day and can be increased to 40mg twice a day after 2 weeks
What if I forget to take it?
If you usually take duloxetine:
once a day - take the missed dose as soon as you remember, unless it's less than 12 hours until your next dose, in which case skip the missed dose
twice a day - take the missed dose as soon as you remember, unless it's less than 4 hours until your next dose, in which case skip the missed dose
Never take 2 doses at the same time to make up for a forgotten one.
If you forget doses often, 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?
The amount of duloxetine that can lead to an overdose varies from person to person.
Call your doctor straight away if you take too much duloxetine and:
- you feel sleepy
- you're being sick (vomiting)
- have tremors
- feel dizzy
- have a fast heart rate
- have a fit (seizure)
- are sweating
- feel restless
If you need to go to a hospital accident and emergency (A&E) department, do not drive yourself - get someone else to drive you or call for an ambulance.
Take the duloxetine packet or the leaflet inside it, plus any remaining medicine, with you.
Like all medicines, duloxetine can cause side effects in some people. But most people have no side effects or only minor ones.
Some of the common side effects of duloxetine will gradually improve as your body gets used to it.
Common side effects
These side effects happen in more than 1 in 100 people.
Keep taking the medicine, but tell your doctor or pharmacist if these side effects bother you or do not go away:
- difficulty sleeping
- feeling dizzy
- blurred vision
- constipation or diarrhoea
- feeling or being sick (nausea or vomiting)
- dry mouth
- less appetite than usual and weight loss
- feeling less interested in sex, or having problems keeping an erection or reaching orgasm
Serious side effects
Serious side effects are rare and happen in less than 1 in 10,000.
Go to A&E immediately if you get:
- tightness in your chest or shortness of breath
- any bleeding that's very bad or that you cannot stop, such as cuts or nosebleeds that do not stop within 10 to 15 minutes
- painful erections that last longer than 4 hours - this may happen even when you're not having sex
Call a doctor straight away if you experience:
- thoughts about harming yourself or ending your life
- hallucinations or become aggressive and angry
- feelings of euphoria, excessive enthusiasm or excitement, or feeling restless that means you cannot sit or stand still
- constant headaches, long-lasting confusion or weakness, or frequent muscle cramps - these can be signs of low sodium levels in your blood (which can cause seizures in severe cases)
- yellowing of the skin, or the whites of your eyes go yellow - these can be signs of a liver problem
- eye pain or blurred vision
- vomiting blood or dark vomit, coughing up blood, blood in your pee, black or red poo - these can be signs of bleeding from the gut
- bleeding from the gums, or bruises that appear without a reason or get bigger
Book an appointment with your doctor if you experience:
- changes in your periods, such as heavy bleeding, spotting or bleeding between periods
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to duloxetine.
Contact a doctor straight away 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
These are warning signs of a serious allergic reaction.
A serious allergic reaction is an emergency.
These are not all the side effects of duloxetine.
For a full list, see the leaflet inside your medicines packet.
You can report any suspected side effect to the UK safety scheme.
What to do about:
- difficulty sleeping - try taking duloxetine first thing in the morning
- headaches - make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Ask your pharmacist to recommend a painkiller. Talk to your doctor if they last longer than a week or are severe.
- feeling dizzy - if duloxetine 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 you do not faint, then sit until you feel better. Do not drive or use tools or machines if you feel dizzy, have muscle cramps or muscle pain, or if you just feel a bit shaky.
- blurred vision - avoid driving or using tools or machines while this is happening. If it lasts for more than a day or two, speak to your doctor as they may need to change your treatment.
- constipation - try to eat more high-fibre foods, such as fresh fruit and vegetables and cereals, and drink plenty of water. Try to exercise more regularly by going for a daily walk or run, for example. If this does not help, talk to your pharmacist or doctor.
- diarrhoea - drink lots of fluids, such as water or squash, to avoid dehydration. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor first.
- feeling or being sick (nausea or vomiting) - stick to simple meals and do not eat rich or spicy food. Make sure you take duloxetine in the morning with some food and try small, frequent sips of water if you're being sick to avoid dehydration.
- dry mouth - chew sugar-free gum or sugar-free sweets
- sweating - try wearing loose clothing, use a strong anti-perspirant, and keep cool using a fan if possible. If this does not help, you may need to try a different type of antidepressant.
- tiredness - do not drive or use tools or machinery if you're feeling this way. Try taking duloxetine 1 hour before bedtime. Cut down the amount of alcohol you drink as this will make you feel more tired. If this symptom does not go away after a week or two, ask your doctor for advice.
- less appetite than usual and weight loss - this side effect should get better as your body gets used to the medicine. It may also help to eat smaller meals more often and eat foods you really enjoy. If your appetite does not improve or you lose a lot of weight, ask your doctor for advice.
- feeling less interested in sex, or having problems keeping an erection or reaching orgasm - speak to your doctor if you experience this side effect and it does not go away.
It's important for you and your baby that you stay well during your pregnancy.
There's no firm evidence that duloxetine is harmful to an unborn baby. But for safety, pregnant women are usually advised to only take it if the benefits of the medicine outweigh the potential risks.
If you become pregnant while taking duloxetine, speak to your doctor. Do not stop taking your medicine unless your doctor tells you to.
If you need to take duloxetine during pregnancy to remain well, your doctor can explain the risks and the benefits to help you decide which treatment is best for you and your baby.
For more information about how duloxetine can affect you and your baby during pregnancy, read the leaflet on the best use of medicines in pregnancy (BUMPS) website.
Duloxetine and breastfeeding
If your doctor or health visitor says your baby is healthy, duloxetine may be used during breastfeeding.
Duloxetine passes into breast milk in very small amounts, but it's not known if it's harmful to the baby.
It's important to continue taking duloxetine to keep you well. Breastfeeding will also benefit both you and your baby.
If you notice that your baby's not feeding as well as usual or seems unusually sleepy, or you have any other concerns about your baby, talk to your health visitor or doctor as soon as possible.
Tell your doctor if you're:
- trying to get pregnant
Some medicines and duloxetine can interfere with each other and increase the chances of you having side effects.
Tell your doctor if you're taking:
- any other medicines for depression - some rarely used antidepressants can interfere with duloxetine to cause very high blood pressure even after you have stopped taking them
- medication used to thin the blood, such as warfarin
- diazepam, chlorphenamine or other medication that can make you feel more sleepy
- tramadol – this can increase the chances of you having certain side effects
Mixing duloxetine with herbal remedies and supplements
Do not take the herbal remedy St John's wort while you're being treated with duloxetine, as this will increase your risk of side effects.
Tell your doctor or pharmacist if you're taking any other medicines, including herbal remedies, vitamins or supplements.
How does duloxetine work?
Duloxetine is a type of antidepressant known as a serotonin-noradrenaline reuptake inhibitor (SNRI).
SNRIs are thought to work by increasing the amount of mood-enhancing chemicals serotonin and noradrenaline in the brain.
When will I feel better?
You may see an improvement after 2 to 4 weeks. Improvements for nerve pain may take longer.
Do not stop taking duloxetine after a week or two just because you feel it's not helping your symptoms.
Give the medicine at least 6 weeks to work.
How will it make me feel?
Antidepressants like duloxetine help to gradually 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.
You'll hopefully take things that used to worry you in your stride.
Do not expect to feel better overnight, though. Some people feel worse during the first few weeks of treatment before they begin to feel better.
If you're taking it for nerve pain or urinary incontinence, you may also notice some of these feelings.
How long will I take it for?
How long you take it for depends on why you're taking it.
For depression or anxiety - once you're feeling better, it's likely that you'll continue to take duloxetine for several more months. Most doctors recommend that you take antidepressants for 6 months to a year after you no longer feel depressed or anxious. Stopping your medicine too soon can make depression and anxiety come back.
For nerve pain or urinary incontinence - if duloxetine is helping your symptoms, you can continue taking it long term. Your doctor may check that you're still having relief from the pain or urinary incontinence every few months.
Is it safe to take it for a long time?
Yes, duloxetine is safe to take for a long time.
How do I come off duloxetine?
If you have been feeling better for 6 months or more, your doctor may suggest coming off duloxetine.
Your doctor will probably recommend reducing your dose gradually over several weeks, or longer if you have been taking duloxetine for a long time.
This is to help prevent any extra side effects you might get as a reaction to coming off the medicine.
- feeling sick
- numbness or tingling in the hands or feet
- trouble sleeping
- feeling agitated or anxious
Do not stop taking duloxetine suddenly or without talking to your doctor first.
How does duloxetine compare to other antidepressants?
Duloxetine is not any better or worse than other antidepressants.
Sometimes people respond better to one treatment than to another.
If you're not feeling any better after 6 weeks, talk to your doctor.
Are there other treatments that'll help?
Taking antidepressants, including duloxetine, is just one of many ways to treat depression and anxiety.
Other potential treatments include:
- talking therapy (such as cognitive behavioural therapy)
- exercise programmes
- help to get a good night's sleep
Choosing a treatment that's most suitable for you depends on:
- how long you have had depression
- your symptoms
- whether you have had any previous periods of depression
- whether previous treatment has worked
- how likely you are to stick with your treatment
- the potential side effects
- your preferences and priorities
There are also other ways to treat nerve pain and urinary incontinence.
If duloxetine is not working for you, speak to your doctor - there may be other treatments you can try.
Is there any food or drink I need to avoid?
You can eat and drink normally while taking duloxetine.
Will I gain or lose weight?
Duloxetine can make you feel less hungry, so you may lose weight.
If you start to have problems with your weight while taking duloxetine, talk to your doctor or pharmacist.
Can I drink alcohol with it?
Yes, you can drink alcohol, but it may make you feel sleepy or tired.
During the first few days of taking duloxetine, it might be best to stop drinking alcohol until you see how the medicine affects you.
Will it affect my fertility?
There's no firm evidence to suggest that taking duloxetine will reduce fertility in either men or women.
But speak to a pharmacist or your doctor before taking it if you're trying to get pregnant.
Speak to your doctor if you're planning to get pregnant while taking duloxetine.
Will it affect my contraception?
Can I drive or ride a bike?
Some people cannot concentrate properly while they're taking duloxetine.
When you first start taking duloxetine, it's a good idea to stop driving and cycling, and avoid using machines or tools, for the first few days until you know how this medicine makes you feel.
Will recreational drugs affect it?
Cannabis can affect the levels of duloxetine and make you more likely to get side effects.
It can be potentially dangerous to take duloxetine with:
- stimulants like MDMA (ecstasy) or cocaine
- hallucinogens like LSD
- novel psychoactive substances (which used to be known as legal highs) like mephedrone
Duloxetine has not been properly tested with recreational drugs.
Talk to your doctor if you think you might use recreational drugs while taking duloxetine.