Can You Use Cymbalta for Fibromyalgia?

Duloxetine (marketed as Cymbalta) is a medication approved by the US Food and Drug Administration (FDA) and recognized by the Australian Rheumatology Association (ARA) as a treatment for reducing pain in fibromyalgia.

If you read any fibromyalgia online forums, you will see there can be quite conflicting experiences when it comes to how people react to this medication, so how do you know if it might be the right fit for you? In this article we outline the benefits of duloxetine for fibromyalgia, how it works, current research outcomes, side effects, where and how to access it.

As with all pharmaceutical approaches to managing fibromyalgia, it's complicated, and medication is unlikely to be a long term solution. We believe that medication is an enabler – helping you to engage in other pain-management approaches that will reshape your pain system over time.

Disclaimer: This article provides generalized information and is not to be used as a substitute for direct medical advice from your doctor or other qualified clinician. It's important to consult with a healthcare professional experienced in the administration of duloxetine for fibromyalgia (such as a rheumatologist) before considering it as a treatment option. They can assess your individual circumstances, any other medications you might be taking and determine if duloxetine is appropriate for you.

What is duloxetine & how does it work?

Duloxetine is a type of medication known as a serotonin and norepinephrine reuptake inhibitor (SNRI). It helps to regulate the level of “feel good” chemicals – serotonin (ser-o-TOE-nin) and norepinephrine (nor-ep-ih-NEF-rin) – in the body.

How? We need to dive into some biochemistry for the answer (this isn't everyone's cup of tea, so if you don't really care how it works, skip ahead to find out if it works!).

Serotonin and norepinephrine are neurotransmitters that regulate the complex pathways of the body’s pain-relief system1 and also affect your mood, sleep-wake cycle and memory. Once they have transmitted their message between cells, they can be taken up and stored for later use. An imbalance or deficiency in serotonin and noradrenaline is associated with key symptoms of fibromyalgia such as fatigue and cognitive deficits2.

Duloxetine binds to serotonin and norepinephrine reuptake receptors, preventing serotonin and norepinephrine from being stored and prompting the body to produce more. This means that higher levels of these feel good hormones exist, which can help regulate mood, pain and sensitization of the nervous system.  

Since its introduction in 2004, duloxetine has been approval by the FDA as a treatment for fibromyalgia (as well as major depression, generalized anxiety disorder, musculoskeletal pain, and osteoarthritis)3. While it is often prescribed to people living with fibromyalgia to target pain relief, this should not be interpreted as a suggestion that those people might be classified as depressed. The use of antidepressant medication for the treatment of chronic pain has become more common.

Besides duloxetine, other antidepressants used for fibromyalgia include milnacipran (Savella), venlafaxine (Effexor XR) and amitriptyline4.

Does duloxetine work for fibromyalgia?

Studies have shown that duloxetine can help reduce pain and fatigue, as well as improve wellbeing and other aspects of a person's health-related quality of life5.

However, research also shows that not all patients benefit from duloxetine treatment and the dose needed is highly variable6,7.

More studies are required to convincingly demonstrate the efficacy of duloxetine for fibromyalgia.

How long does it take for duloxetine to work for fibromyalgia?

Like any new medication, it can take several weeks before you would notice any change in symptoms from taking duloxetine for fibromyalgia.

As we know, everyone experiences fibro differently and for some people, there might be a slight effect after a week but, for others, it may take up to two months to feel the full effect. If you are noticing a change in symptoms or experiencing concerning side effects, always check with your healthcare team and do not change medication on your own.

What are the side effects for duloxetine?

Possible side effects of duloxetine may include:

  • nausea and vomiting
  • diarrhea
  • headache
  • fatigue and drowsiness including insomnia
  • high blood pressure
  • racing heart
  • excessive sweating
  • liver failure
  • suicidal thoughts
  • reduced libido and sexual enjoyment
  • agitation
  • cholesterol and triglyceride elevation
  • tremors.

Research studies have reported participants dropping out of clinical trials due to side effects with duloxetine predominantly because of nausea and drowsiness8.

However, some people may experience suicidal thoughts and behavior, as well as other severe psychiatric adverse events, especially in young people9. It is for this reason that duloxetine is not recommended for young people or with a history of previous suicidality. If you are experiencing suicidal thoughts or in an urgent mental health crisis, please reach out for help immediately.

One of the effects of taking duloxetine is increased energy levels, and for some people, this can impact your ability to wind down at night and get restorative sleep. This is a common negative side effect reported in online forums and in clinical studies on the impact of antidepressants10.

People often ask about sexual side effects of a medication like duloxetine because sexual dysfunction can be a common side effect of antidepressants11. Based on placebo-controlled clinical trials, male patients on Cymbalta experienced significantly more sexual dysfunction compared to placebo12.

In the long term, duloxetine usage may result in hypertensive crisis, Steven-Johnson Syndrome, withdrawal syndrome, serotonin syndrome or liver failure13. If you notice any signs of liver dysfunction (darkened urine, abdominal pain, flu-like symptoms or yellow skin or eyes (jaundice), seek immediate medical attention.

Ongoing monitoring including regular blood tests are recommended to check for any possible deterioration in liver function.

Knowledge is power

Receive free science-backed tips and advice to learn about your fibromyalgia and what can help.
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.

What should I avoid when taking duloxetine?

Some pharmaceutical and herbal treatments are not recommended for use with duloxetine. Other antidepressant medications, particularly a class called Monoamine Oxidase Inhibitors (MOAIs) and the herbal remedy for depression is St John's Wort can put a person at increased risk of developing a serious side effect called serotonin syndrome. In nearly all patients with serotonin syndrome, symptoms (that can range from mild such as shivering and diarrhea to severe such as muscle rigidity, fever and seizures) develop within 24 hours of exposure14. If you notice any of these symptoms, seek medical advice.

Alcohol is not recommended due to the possible impacts on the liver as well as the possibility of making some drug side effects worse.

How should I take duloxetine?

When used for fibromyalgia, it is typically taken as a 60mg capsule in the morning. Some studies have investigated a maximum dose of 120mg but trials of higher dosage were associated with more adverse reactions/side effects and prematurely stopping treatment15.

How can I get duloxetine and what does it cost?

If duloxetine is something you might be willing to try, begin by having a frank discussion with your health provider about whether it may be appropriate for you. Be sure to outline any other co-occurring conditions that you might have and current medications as this may impact your suitability for taking duloxetine.

It is important to be clear that duloxetine is a prescription-only drug, so you will need to obtain a prescription for its use. There are some helpful resources available about important considerations about buying medication online.

Typically, you will pay less than $30 AUD for a single box of 28 capsules (60mg) so this works out to be around $1/day.

In the US, duloxetine is approved by the US Food and Drug Administration (FDA) for fibromyalgia treatment and is likely to cost around $15 USD per month and may or may not be covered by your insurance.

What about duloxetine & withdrawal symptoms?

What happens if you start taking a drug, realize it is not really working for you and want to stop it? This is a decision to be considered thoughtfully and made with the support of your doctor.

If a drug is boosting your “feel good” chemicals then ceasing or gradually tapering will result in a drop of these and, as the body, readjusts to newer levels, there may be a period of feeling pretty crappy – in essence, the reverse of what the drug was doing – so increased pain, decreased mood. This is a psychological response and is not the same as withdrawal symptoms including craving and drug-seeking behavior that can come from ceasing addictive drugs.

Duloxetine has a half-life of 12 hours and is thought to be completely out of your system within 2-3 days but this is generally when withdrawal symptoms will commence and how long they last depends on how long you have been taking a medication and how you taper off in dosage.

Clinical trials indicate there can be significant withdrawal symptoms with the cessation of duloxetine16.  More broadly, in a survey more broadly of antidepressant medications including SNRIs like duloxetine, more than half (56%) of people who attempt to come off antidepressants experience withdrawal effects and nearly half (46%) of people experiencing withdrawal effects describe them as severe17.

While these withdrawal symptoms vary in prevalence and severity, we have heard reports of this being a major challenge from members of our MoreGoodDays community and other fibromyalgia forums and support groups. Before commencing any new drug, a conversation with your health professional needs to address the long term plan for medication use including eventual cessation.

What else to consider?

If you are considering Cymbalta for fibromyalgia, your doctor will be best placed to talk about potential benefits and side-effects and advise on the right approach for you.

For more information, or a simple summary to take with you to discuss this treatment options with your healthcare provider, you can read the Australian Rheumatology Association Duloxetine information Sheet.

It is important to remember that medication is not a stand alone treatment for fibromyalgia. There are also other management options for your fibromyalgia such as education, lifestyle changes and support.

If you need some more support, our MoreGoodDays app includes information on how to navigate different medications for fibromyalgia, how to know when it is or isn’t working for you, how to advocate yourself in health care appointments to get what you need. If you’d like to learn more, why not download it to try it out for free via the App Store or the Play Store.