Duloxetine (Cymbalta) Side Effects

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Duloxetine (Cymbalta) is a prescription drug which is used to treat major depressive disorder.and generalized anxiety disorder.  It is also used to treat the pain associated with diabetic peripheral neuropathy, fibromyalgia, osteoarthritis and chronic low back pain.

Like any medication, it is possible that you may have certain unwanted effects called side effects while using it.

Most Common Side Effects

Some of the most commonly seen side effects with duloxetine are:

  • Upset stomach
  • Dry mouth
  • Sleepiness
  • Fatigue
  • Dizziness
  • Constipation
  • Decreased appetite
  • Excessive sweating

This is not a complete list of all possible side effects.  You should consult with your doctor or pharmacist if you would like a full listing.

More Serious Side Effects

Some side effects, although not very common, can be more serious if you do experience them.  It is extremely important that you consult with a doctor if any of these side effects happen to you while using duloxetine:

  • Suicidal thoughts or actions or worsening depression
  • Liver damage - Signs include itching, right upper abdominal pain, dark-colored urine, yellow skin or eyes, enlarged liver or increased liver enzymes (detectable by a blood test)
  • Serotonin syndrome - Symptoms include agitation, hallucinations, changes in consciousness, problems with coordination, twitching muscles, rapid heartbeat, high or low blood pressure, sweating or fever, upset stomach, vomiting, diarrhea or rigid muscles.
  • Abnormal bleeding
  • Severe skin reactions - Signs to look for include blisters, peeling rash, mouth sores, hives or other signs of an allergic reaction.
  • Mania or hypomania - Symptoms include increased energy, problems with sleep, racing thoughts, impulsive behavior, grandiose thoughts, euphoric mood, irritability, rapid and excessive speech.
  • Eye problems such as pain, swelling around the eye or vision changes
  • Seizures or convulsions
  • Increasing or decreasing blood pressure
  • Low sodium in the blood - Symptoms include headache; weakness; confusion; difficulty with thinking, concentration or memory.
  • Problems with urination
  • Changes in appetite or weight

What You Should Do If You Experience Side Effects

Usually people taking duloxetine will have only minor side effects which will become less as they adjust to the medication.  However, if your find yourself not able to tolerate its side effects and they aren't improving, your doctor will be able to help.  Some of the things that he or she might do to help you include giving you tips for coping with them or prescribing medications to counteract them.  If these measures do not help, then your doctor may also be able to switch you to a different antidepressant with fewer side effects.

It is especially important for you to be aware of the more severe side effects that are possible with duloxetine.

  While they will probably not happen to you, if they do, it is possible that they can damage your health or even cause death if not treated promptly.  You should always seek immediate medical care if you have any signs of these side effects.

When unpleasant side effects do occur, it may be tempting to stop taking your medication altogether.  You should, however, be aware that if you stop taking your medication suddenly you run the risk of worsening or returning depression.  In addition, you may experience a set of symptoms called discontinuation syndrome.  Discontinuation syndrome includes such symptoms as muscle aches, headaches, nausea, fatigue and strange neurological sensations.  Following your doctor's advice when changing or stopping your medication is the best way to prevent these problems.


"Cymbalta."  PDR Health Physicians' Desk Reference.  PDR Network, LLC.  Accessed:  December 27, 2014.  http://www.pdrhealth.com/drugs/cymbalta

"Duloxetine." AHFS Consumer Medication Information. Bethesda, MD : American Society of Health-System Pharmacists, Inc., 2013. Revised: Jan 15, 2012. Accessed: December 27, 2014. http://www.nlm.nih.gov/medlineplus/druginfo/meds/a604030.html#side-effects

"Medication Guide Cymbalta (Duloxetine Delayed-Release Capsules)."  Food and Drug Administration. Accessed: December 27, 2014. http://www.fda.gov/downloads/Drugs/DrugSafety/ucm088579.pdf

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