Duloxetine is an antidepressant medicine. It is also sometimes prescribed for other conditions.
It's known in Ireland by the brand names Cymbalta, Loxentia and Yentreve.
Duloxetine comes as capsules and is only available on prescription.
Uses of duloxetine
Duloxetine is used to treat:
- depression
- anxiety
- nerve pain
- stress urinary incontinence in women
When you start taking duloxetine
Duloxetine normally takes 2 to 4 weeks to work. It may take longer if you're taking it for nerve pain.
You may have some common side effects.
Do not stop taking duloxetine after 1 or 2 weeks if you think it's not helping your symptoms. Give it at least 6 weeks to work.
Do not drink alcohol for the first few days of taking duloxetine. This will let you see how the medicine affects you.
Check if you can take duloxetine
You can only take duloxetine if you’re age 18 or older.
Only women can use duloxetine for stress urinary incontinence.
Before your GP prescribes duloxetine, tell them if you:
- have any other medical conditions - such as kidney or liver problems, heart problems, glaucoma, seizures or fits, manic depression or bipolar disorder
- are taking other medicines or supplements, including other medicines for depression that you have taken within the last 14 days
- had an allergic reaction to medicine in the past
- have thoughts about harming yourself or ending your life
- are trying to get pregnant, already pregnant or breastfeeding
Pregnancy and duloxetine
Talk to your GP or pharmacist before taking duloxetine if you are pregnant, think you may be pregnant or are planning to have a baby.
You should only take duloxetine during pregnancy if the benefits of the medicine outweigh the potential risks.
If you are taking duloxetine, do not stop taking it unless your GP tells you to.
Breastfeeding and duloxetine
You can take duloxetine when you’re breastfeeding or planning to breastfeed.
Duloxetine gets into breast milk in very small amounts. It has not been known to cause side effects in breastfed babies.
Speak to your GP about which treatment is best for you if you are breastfeeding.
How and when to take it
How much duloxetine you take will depend on what you're taking it for.
You usually take it once a day for depression and anxiety. You take it twice a day for nerve pain and urinary incontinence.
You can take duloxetine with or without food, but it's best to take it at the same time each day.
Swallow the capsules whole with water or juice. Do not chew them.
Important
Do not stop taking duloxetine suddenly without talking to your GP first.
Taking duloxetine for depression or anxiety
When you're feeling better, your GP may recommend that you continue taking duloxetine for a few more months. This is to avoid relapse.
They will tell you to how best to come off duloxetine. Stopping your medicine too soon can make depression and anxiety return.
Taking duloxetine for nerve pain or urinary incontinence
You can take duloxetine long term if it helps your symptoms. Your GP may check that you're still getting relief from the pain or urinary incontinence every few months.
If you forget to take it
If you miss a dose of duloxetine, take your missed dose as soon as you remember.
But skip the missed dose if you take duloxetine:
- once a day and it's less than 12 hours until your next dose
- twice a day and it's less than 4 hours until your next dose
Important
Never take 2 doses at the same time to make up for a forgotten dose.
If you take too much
If you take too much duloxetine, you may:
- feel sleepy
- get sick (vomit)
- have tremors
- feel dizzy
- have a fast heart rate
- sweating
- feel restless
Urgent advice: Call your GP or pharmacist straight away if:
- you take more than your recommended dose of duloxetine
Emergency action required: Call 112 or 999 or go to an emergency department if:
- you take more than your prescribed dose of duloxetine and have a fit (seizure)
If you need to go to an ED do not drive yourself. Get someone to drive you or call 112 or 999 for an ambulance.
Bring the packet or leaflet and any remaining medicine with you.
Side effects
Some of the common side effects of duloxetine will gradually improve as your body gets used to it. Keep taking the medicine.
Contact your GP or pharmacist if these side effects bother you or do not go away.
Common side effects
There are things you can do to manage common side effects:
Difficulty sleeping
Try taking duloxetine first thing in the morning.
Headache
Rest and drink plenty of fluids. Do not drink alcohol.
Ask your pharmacist to recommend a painkiller. Talk to your GP if the headaches 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, cycle or use tools or machinery if you feel dizzy.
Blurred vision
Avoid driving, cycling or using tools or machinery while this is happening. If it lasts for more than 1 or 2 days, your GP may need to change your treatment.
Constipation
Try to get more fibre into your diet, such as fresh fruit, vegetables and cereals, and drink plenty of water.
Try to exercise more regularly, for example by going for a daily walk or run.
Diarrhoea
Drink lots of fluids, such as water or squash, to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee.
Do not take medicines to treat diarrhoea without speaking to a pharmacist or GP.
If you take the combined contraceptive pill or the progestogen-only pill and you have severe diarrhoea for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice.
Feeling sick (nausea)
Stick to simple meals and do not eat rich or spicy food. Make sure you take duloxetine in the morning with some food.
Getting sick (vomiting)
Try small, frequent sips of water if you're getting sick to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee.
If you take the combined contraceptive pill or the progestogen-only pill and you're getting sick, your contraception may not protect you from pregnancy. Check the pill packet for advice.
Dry mouth
Chew sugar-free gum or suck sugar-free sweets.
Sweating
Try wearing loose clothing, use a strong anti-perspirant and keep cool using a fan, if possible.
Tiredness
Do not drive, cycle or use tools or machinery if you're feeling very tired.
Try taking duloxetine 1 hour before bedtime. Try to avoid drinking alcohol as alcohol will make you feel more tired.
If the tiredness does not go away after 2 weeks, ask your GP for advice.
Lack of appetite and weight loss
This side effect should get better as your body gets used to the medicine. 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 GP for advice.
Loss of interest in sex
Contact your GP if you get this side effect and it does not go away.
Serious side effects
Serious side effects are rare.
Emergency action required: Call 112 or 999 or go to an emergency department (ED) immediately if you have:
- tightness in your chest or shortness of breath
- bleeding that does not stop after 10 to 15 minutes - for example, from a cut or nosebleed
- painful erections that last longer than 2 hours - this may happen even when you're not having sex
- thoughts about harming yourself or ending your life
Urgent advice: Contact your GP urgently if you have:
- hallucinations (seeing or hearing things that are not real) or become aggressive and angry
- feelings of euphoria, excessive enthusiasm or excitement or feeling restless
- constant headaches, long-lasting confusion or weakness, or frequent muscle cramps - these can be signs of low sodium levels in your blood
- yellowing of the skin or the whites of your eyes (jaundice) - this can be signs of a liver problem
- eye pain or blurred vision
- vomiting blood or dark vomit, coughing up blood, blood in your pee, blood in your poo - can be red or black
- bleeding from the gums, or bruises that appear without a reason or get bigger
Non-urgent advice: Contact your GP if:
- you have changes in your periods, such as heavy bleeding, spotting or bleeding between periods
This is not a full list of side effects of duloxetine.
Read the patient information leaflet that comes with your medicine for a full list of side effects.
Non-urgent advice: Find your patient information leaflet
Your patient information leaflet is the leaflet that comes with your medicine. You can find a digital version of the leaflet online.
Report side effects
You can report any suspected side effects to the Health Products Regulatory Authority (HPRA): report an issue - hpra.ie
Serious allergic reaction
A serious allergic reaction to duloxetine is rare.
Emergency action required: Call 112 or 999 or go to an emergency department (ED) if:
- you get a rash that is itchy, red, swollen, blistered or peeling
- you're wheezing
- you get tightness in your 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 (anaphylaxis) and you might need to go to hospital.
Taking duloxetine with other medicines
Some medicines and duloxetine can affect each other and increase the chances of you having side effects.
Tell your GP or pharmacist if you're taking:
- any other medicines for depression - some rarely used antidepressants can affect duloxetine and cause very high blood pressure even after you have stopped taking them
- medicine used to help prevent blood clots, such as warfarin
- other medicines that can make you feel more sleepy - such as diazepam or some types of antihistamines
- tramadol (painkiller also known as Zydol, Zymel, Ixprim)
Do not take the herbal remedy St John's wort while you're being treated with duloxetine. This will increase your risk of side effects.
Recreational drugs
Cannabis can interfere with duloxetine and make you more likely to get side effects.
It may be dangerous to take duloxetine with:
- stimulants - such as MDMA (ecstasy) or cocaine
- hallucinogens - such as LSD
- novel psychoactive substances (sometimes called legal highs) - such as mephedrone
Fact check
This content was fact checked by a pharmacist, a GP, the National Medication Safety Programme (Safermeds) and the Health Products Regulatory Authority (HPRA).
