Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs) for Fibromyalgia
Guide
Examples
| Generic Name | Brand Name |
|---|---|
| duloxetine | Cymbalta |
| milnacipran | Savella |
| venlafaxine | Effexor |
How It Works
SNRIs work to increase the activity of brain chemicals called serotonin and norepinephrine. Doctors do not know exactly how this improves fibromyalgia symptoms.
Why It Is Used
Doctors may prescribe serotonin and norepinephrine reuptake inhibitors (SNRIs) when mood problems are a major symptom of fibromyalgia. SNRIs are also used for people without fibromyalgia who have depression.
How Well It Works
Some people with fibromyalgia who take SNRIs notice an improvement in a number of symptoms, including depression, pain, and fatigue. But it's hard to tell if SNRIs will work for you and how much they will help. A review of studies showed a small improvement in pain. But the same review showed no improvement in sleep problems for people taking the medicine.1
Side Effects
All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.
Here are some important things to think about:
- Usually the benefits of the medicine are more important than any minor side effects.
- Side effects may go away after you take the medicine for a while.
- If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.
Call911or other emergency services right away if you have:
- Trouble breathing.
- Swelling of your face, lips, tongue, or throat.
Duloxetine
Call your doctor right away if you have:
- Hives.
- Thoughts of suicide.
- Agitation and restlessness.
- Dark urine or light-colored stool.
- Nausea and vomiting.
- Yellow eyes and skin (jaundice).
- Upper right abdominal pain.
Venlafaxine
Call your doctor right away if you have:
Common side effects of these medicines include:
- Constipation.
- Cough.
- Decrease in sexual desire or ability.
- Dizziness.
- Dry mouth.
- Increased sweating.
- Headache.
- Nausea and loss of appetite.
- Sleep problems.
- Weight loss.
The U.S. Food and Drug Administration (FDA) has issued:
- An advisory on antidepressant medicines and the risk of suicide. Talk to your doctor about these possible side effects and the warning signs of suicide.
- A warning about taking triptans, used for headaches, with SSRIs (selective serotonin reuptake inhibitors) or SNRIs (selective serotonin/norepinephrine reuptake inhibitors). Taking these medicines together can cause a very rare but serious condition called serotonin syndrome.
See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)
What To Think About
Never suddenly stop taking SNRIs. The use of any antidepressant should be tapered off slowly and only under the supervision of a doctor. Abruptly stopping antidepressant medicines can cause negative side effects or a relapse of your condition.
SNRIs are started at low doses, and the dose is increased gradually to reduce the severity of side effects. You may need regular blood tests to check the amount of the medicine in your blood. Too much of this type of medicine in the bloodstream can be dangerous.
Treatment with antidepressants does not always relieve symptoms caused by fibromyalgia. Even when the treatment does work, some people may find the side effects of these medicines unacceptable.
Using an antidepressant medicine to treat fibromyalgia does not mean that the condition is "all in your head."
Be sure to tell your doctor about all the medicines you are currently taking. Duloxetine and milnacipran can interact poorly with monoamine oxidase (MAO) inhibitors (taken for depression and other mental health conditions). Examples of MAO inhibitors include phenelzine, selegiline, and tranylcypromine.
Duloxetine can affect blood sugar levels in people with diabetes. If you notice that the results of your blood sugar tests are different than you expect, or if you have any questions, talk to your doctor.
Venlafaxine makes bleeding more likely in the upper gastrointestinal tract (stomach and esophagus). Taking venlafaxine with NSAIDs (such as Aleve or Advil) makes bleeding even more likely. Taking medicines that control acid in the stomach may help.2
Taking medicine
Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.
There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.
Advice for women
If you are pregnant, breast-feeding, or planning to get pregnant, do not use any medicines unless your doctor tells you to. Some medicines can harm your baby. This includes prescription and over-the-counter medicines, vitamins, herbs, and supplements. And make sure that all your doctors know that you are pregnant, breast-feeding, or planning to get pregnant.
Checkups
Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.
Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.
Citations
Häuser W, et al. (2013). Serotonin and noradrenaline reuptake inhibitors (SNRIs) for fibromyalgia syndrome. Cochrane Database of Systematic Reviews (1).
Abajo FJ, Garcia-Rodriguez LA (2008). Risk of upper gastrointestinal tract bleeding associated with selective serotonin reuptake inhibitors and venlafaxine therapy. Archives of General Psychiatry, 65(7): 795-803.
ByHealthwise Staff
Primary Medical ReviewerAnne C. Poinier, MD - Internal Medicine
Specialist Medical ReviewerKarin M. Lindholm, DO - Neurology