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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Duloxetine

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.
  • Duloxetine can make some people think about hurting themselves or committing suicide. You must go straight to hospital with your tablets if you have any of these thoughts.
  • 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 serious side-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
  • Eating disorders such as bulimia nervosa and binge eating disorder
  • Panic Disorder 
  • Generalised Anxiety Disorder
  • Obsessive Compulsive Disorder
  • Body Dysmorphic Disorder
  • Social anxiety
  • Phobias

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.

  • Experiments suggest that depression or low mood is more likely to happen when the brain doesn’t have enough of a chemical called serotonin (also called ‘5HT’) and noradrenaline.
  • Receptors in the brain release these chemicals and then take them back up again in a cycle.
  • SNRI antidepressants like duloxetine block these chemicals being taken back up into the brain cells.
  • This means that the amount of serotonin and noradrenaline increases and the depression and low mood becomes 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.
  • You may start taking duloxetine at a lower dose, and increase the dose gradually to the one that is right for you.
  • 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 level of serotonin feeds back to the brain that it should make less of it (this means you do not feel any better).
  • But after some days of regular treatment, the feedback receptors send fewer messages and the brain gradually releases more serotonin. 

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 8 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.
  • It could take a long time to work for you, but hopefully it will be worth sticking with it.
  • 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 you cannot live with, then talk to your doctor about other options.

Reference sources

YM Clinician Survey 2013

Cymbalta PIL 1 last updated January 2017
https://www.medicines.org.uk/emc/PIL.15601.latest.pdf Accessed 21/02/2017

Cymbalta PIL 2 last updated January 2017
https://www.medicines.org.uk/emc/PIL.15601.latest.pdf Accessed 21/02/2017

Cymbalta PIL 3 last updated January 2017
https://www.medicines.org.uk/emc/PIL.15601.latest.pdf Accessed 21/02/2017

Cymbalta PIL 4 last updated January 2017
https://www.medicines.org.uk/emc/PIL.15601.latest.pdf Accessed 21/02/2017

Cymbalta SPC 4.1 last updated 8 Feb 2017
https://www.medicines.org.uk/emc/medicine/15694 Accessed 21/02/2017

Cymbalta SPC 4.2 last updated 8 Feb 2017
https://www.medicines.org.uk/emc/medicine/15694 Accessed 21/02/2017

Cymbalta SPC 4.4 last updated 8 Feb 2017
https://www.medicines.org.uk/emc/medicine/15694 Accessed 21/02/2017

Cymbalta SPC 4.8 last updated 8 Feb 2017
https://www.medicines.org.uk/emc/medicine/15694 Accessed 21/02/2017

Maudsley 12th ed p609 (eating disorders)

Maudsley 12th edition p473

Neal MC. Medical Pharmacology at a Glance (7th Edition). Oxford: John Wiley & Sons, 2012. P63

BNF 70 p288

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