Antidepressants: Another tool against chronic pain

By Mayo Clinic Staff

Some medicines used for chronic pain started as treatments for other conditions. For instance, healthcare professionals widely prescribe antidepressants for chronic pain conditions, even when depression isn’t involved. Chronic pain is pain that lasts for three months or more.

Antidepressants seem to work best for pain caused by:

• Arthritis.
• Nerve damage from diabetes and other causes. This is called neuropathic pain.
• Facial pain.
• Fibromyalgia, a condition of widespread body pain.
• Low back pain.
• Pelvic pain.

These medicines may help block pain by raising levels of the brain chemical serotonin. Serotonin blocks pain and improves mood.

Antidepressants don’t work right away. You may feel some relief from an antidepressant after a week or so. But the greatest relief may take several weeks.

Some people take anticonvulsants or other types of medicines that help relieve pain with an antidepressant.

Antidepressants are grouped by how they work. Tricyclic antidepressants are one type of antidepressant that works for pain.

Tricyclic antidepressants are the most-used type of antidepressant for pain. They include:

• Amitriptyline.
• Nortriptyline.
• Protriptyline.
• Doxepin (Silenor).
• Imipramine.
• Clomipramine (Anafranil).
• Desipramine (Norpramin).

Side effects of tricyclic antidepressants may include:

• Blurred vision.
• Sleepiness
• Dry mouth.
• Upset stomach.
• Dizziness.
• Weight gain.
• Trouble passing stool, called constipation.
• Trouble urinating.
• Heart rhythm issues.
• Trouble having sex.

To lessen or prevent side effects, you may start with a low dose. Your healthcare professional then slowly raises the dose. Most people who take tricyclic antidepressants in low doses have only mild side effects. The doses that work for pain are most often lower than the doses for depression.

Other classes of antidepressants have become more popular because they have fewer side effects. These medicines also may help relieve chronic pain:

• Serotonin and norepinephrine reuptake inhibitors (SNRIs). Some SNRIs may help relieve chronic pain. Examples include venlafaxine (Effexor XR), duloxetine (Cymbalta, Drizalma Sprinkle), milnacipran (Savella) and desvenlafaxine (Pristiq).

  People with lasting pain often get depressed, as well. Venlafaxine and duloxetine help relieve depression at the same dosages that can treat pain.

  A Cochrane Database review of antidepressants used for pain found that the standard dose of duloxetine worked better than other antidepressants to relieve pain. But the review didn’t look at how well the antidepressants worked for different pain conditions.

  Venlafaxine and duloxetine can cause drowsiness, dry mouth and trouble passing stool. Venlafaxine also can raise blood pressure and may make heart issues worse.

  Milnacipran is used to relieve fibromyalgia pain. But whether it works for other types of pain needs more study. It can cause side effects such as upset stomach and dizziness.

• Selective serotonin reuptake inhibitors (SSRIs). SSRIs may help relieve some types of pain. But there’s little proof. SSRIs include paroxetine (Paxil) and fluoxetine (Prozac).

  SSRIs may help some tricyclic antidepressants work better. Taking them together raises the level of both medicines, which may raise the risk of side effects. If you take both medicines, talk with your healthcare professional about how to take them safely.

  SSRIs most often don’t work as well as tricyclic antidepressants for pain. But they often have fewer side effects.

Antidepressant medicines are linked with a slightly higher risk of suicidal thoughts or actions. If you have thoughts of suicide, there is help. In the United States, call or text 988 to reach 988 Suicide & Crisis Lifeline.

Before starting an antidepressant, review the medicines you take and your medical history with your healthcare professional. That’s to help make sure the antidepressant is right for you.