Serotonin and norepinephrine reuptake inhibitors (SNRIs). Some SNRIs, such as venlafaxine (Effexor XR), duloxetine (Cymbalta, Drizalma Sprinkle), milnacipran (Savella) and desvenlafaxine (Pristiq), may help relieve chronic pain. People with chronic pain often develop depression along with their chronic pain. Venlafaxine and duloxetine offer the advantage of being effective for depression and anxiety at the same dosages useful for treating pain.
Venlafaxine can cause drowsiness, insomnia or elevated blood pressure, and may worsen heart problems. Duloxetine can cause side effects, such as drowsiness, insomnia, nausea, dry mouth, dizziness, constipation or excessive sweating.
Milnacipran is used to relieve fibromyalgia pain and can cause side effects such as nausea and drowsiness. However, it has shown only limited effectiveness in relieving other types of pain.
Selective serotonin reuptake inhibitors (SSRIs). SSRIs, which include drugs such as paroxetine (Paxil) and fluoxetine (Sarafem, Prozac), may help relieve certain types of pain, but there's a lack of evidence that they help alleviate nerve pain.
SSRIs may boost the painkilling effects of some tricyclic antidepressants by increasing the levels of tricyclic antidepressants in your blood. If your doctor prescribes both medications, they should be used with caution. If you have any concerns, talk with your doctor.
SSRIs generally don't work as well as tricyclic antidepressants for pain, but they often produce fewer side effects. Fluoxetine can cause certain side effects, such as insomnia and dizziness.