HeadMeds gives young people in the United Kingdom general information about medication. HeadMeds does not give you medical advice. Please talk to your Doctor or anyone else who is supporting you about your own situation because everyone is different. Please read more important details about our site.

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Return to Duloxetine overview
  1. Use and Action
  2. Warnings and side effects
  3. Sex, drink, weight and everything else

Headmeds fills the medicines information gaps for young people - things you might want to know about meds like will it affect my sex life? Can I still study?  Can I drink?
Headmeds does not give medical advice so this is just general information.
Each medicine has a balance of good and bad effects, and each person gets their own individual effects.
You might want to know just one thing about your medicine, but on each page we have given you the ‘safety headlines’. Please read them as they are important.
We have included lots of information about each medicine - but if you want all the details, please look at the patient information leaflet - which is inside every pack. These leaflets are also at www.medicines.org.uk - where there will be the most up-to-date information.

Safety Headlines 

  • If you have taken more duloxetine than it said on the label, you must see a doctor quickly – even if you do not feel any different.
  • As part of depression some people think about hurting themselves or committing suicide. Taking an antidepressant may not stop this. You must get some urgent help if you are having these sorts of thoughts. Speak to someone who is looking after you or go straight to hospital with your tablets.
  • Duloxetine can also cause other serious side-effects: allergic reactions (difficulty breathing, swelling of your face or throat, itching skin lumps), and other serious symptoms that you can find here. Go to a hospital if you get any of these symptoms, with your medicine.
  • Do not take duloxetine if you have taken a monoamine oxidase inhibitor antidepressant (MAOI) like moclobemide, phenelzine, isocarboxazid or tranylcypromine in the last 14 days.
  • Stopping duloxetine suddenly can cause unpleasant withdrawal effects – go to your doctor if you want to stop, or if you are having these effects.
  • You may feel sleepy, and your eyesight might be affected, in the first few days after taking duloxetine – do not drive a car, ride a bike or operate machines until you see how this affects you.
  • If you take duloxetine while you are pregnant, it may affect the developing baby. Use good contraception while you are taking duloxetine. It can also cause symptoms in newborn babies if you take it at the end of pregnancy. Talk to your doctor or midwife about this and get their help.

Duloxetine can be used for some mental health conditions

  • Low mood (depression)
  • Generalised anxiety disorder
  • It may be used to help with nerve pain in people with diabetes (diabetic neuropathy)
  • It is also prescribed for women with stress incontinence. For this use the dose is different and a 20mg or 40mg strength product will be prescribed

Duloxetine can help to adjust the chemicals your brain needs

The brain is usually good at making sure we have enough of the chemicals we need to function properly.

  • Research suggests that depression or low mood is more likely to happen when the brain doesn’t have enough of the chemicals called serotonin (also called ‘5HT’) and noradrenaline.
  • Nerve endings in the brain release these chemicals and then after they have targeted their receptors take them back up again in a re-cycling process.
  • SNRI antidepressants like duloxetine work by blocking recycling of released serotonin and noradrenaline back in to the nerve endings.
  • This means that the amount of serotonin and noradrenaline increases and the depression and low mood gets better.

You usually take duloxetine once a day

  • You will get the best effect from duloxetine if you take it regularly every day.
  • Make sure that you know your dose. If it is not written on the label, check it with your pharmacist or doctor.
  • In depression, you are likely to start taking duloxetine at the standard treatment dose. You may be started on a lower dose and the dose built up if you are taking it for anxiety 
  • Choose a time each day that you can always remember. This could be a mealtime, or when you brush your teeth.
  • You can take it before or after food.
  • Swallow the capsule with a drink of water - if you chew it, it tastes bitter.

If you forget to take a dose then just take it as soon as possible, but do not double dose

What to do if you miss a dose:

  • If you remember later during the day, take it as soon as possible.
  • If you forget to take it by the time of your next dose, only take the next dose.
  • Do not take a double dose. 

What might happen?

  • If you forget to take it for a few days, you may start getting withdrawal symptoms and should talk to your doctor about it.

You must go to A&E if you take too much

What to do if you take too much:

  • If you have taken more duloxetine than it said on the label, you must get help quickly – even if you do not feel any different.
  • Go to A&E. Take your medicine with you, to show to the doctors. Tell them how much you have taken.
  • Get a friend or family member to go with you, if you can, just in case you feel ill on the way. 
  • You might get any of the following signs:
  • feeling sick or being sick
  • having fits
  • an irregular heartbeat or a heart attack
  • extreme sleepiness that could lead to a coma.

You are also at risk of getting ‘Serotonin syndrome’. This is when you can get a high fever, agitation, confusion, trembling, feeling drunk or getting weird movements of your muscles. This is rare, but you should watch out for it.

It can take 2-4 weeks for duloxetine to start helping  

  • It takes 2-4 weeks for duloxetine to start helping, and it could take some weeks or months to get its full effect. We do not know why.
  • To get the best effect, you need to take your duloxetine every day and give it a chance to work for you.
  • Scientists believe that at first the higher levels of serotonin (and possibly noradrenaline) have direct effects which do not help relieve the depression or anxiety. In fact you are likely to feel a bit more anxious or on edge for a couple of weeks.
  • But after some days of regular treatment, adaptive changes take place in the brain which lead to improvements in mood and anxiety.

Your doctor might start you on a low dose and then increase it slowly over 2-4 weeks to your full dose.

  • If there has been no good effect after 4 weeks on duloxetine, it is probably not the best medicine for your condition.

Most people take duloxetine for at least 6 months

  • You and your doctor should talk about how long you need to take duloxetine.
  • Take duloxetine until you feel better (which probably takes 1-2 months), and then take them for another 6-12 months as advised by your doctor.
  • This will help keep you well.
  • If you get side-effects that really bother you, then talk to your doctor about other options.

Reference sources

Search www.medicines.org.uk to find patient information leaflets and prescribing information on duloxetine. The 20mg and 40mg capsule strengths (including Yentreve) are for stress incontinence in women. The 30mg and 60mg capsule strengths (including Cymbalta) are the ones to search. The SmPC lists all the inactive ingredients in the product so you can check against any allergies. If you are still unsure about this then speak to your pharmacist.

  • British National Formulary (BNF) and British National Formulary for children. Download the BNF/BNFC app (blue background) on to your mobile device. No longer available for public access via the web
  • Taylor D, Barnes T, Young A. Maudsley Prescribing Guidelines in Psychiatry, 13th edition. Oxford: John Wiley & Sons, May 2018. ISBN: 978-1-119-44260-8
  • Royal Pharmaceutical Society. Medicines Ethics and Practice (42nd edition). London: RPS, 2018. Standards for pharmacists to work to. It is not a free publication
  • World Anti Doping Agency WADA Prohibited List https://www.wada-ama.org/en/resources/science-medicine/prohibited-list-documents
  • Choiceandmedication; an independent source of information on many mental health conditions and their medicines with easy to read fact sheets www.choiceandmedication.org Personal subscriptions to download the app available for £1 per month (with proportionate discounts for longer periods) but your local mental health Trust may subscribe and provide information sheets for free.
  • Best Use of Medicines in Pregnancy (BUMPS). Information sheets on drugs in pregnancy http://www.medicinesinpregnancy.org/
  • Drugs and Lactation Database (LactMed). Information on drugs in breastfeeding https://toxnet.nlm.nih.gov/newtoxnet/lactmed.htm