SNRIs and the Treatment of Bipolar Disorder

By Candida Fink, Joe Kraynak

Selective Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs) increase the levels of two brain chemicals — serotonin and norepinephrine — in the synapses between brain cells. As with SSRIs, the full mechanism of action of SNRIs is poorly understood. But researchers know that, like serotonin, norepinephrine plays an important role in regulating mood and anxiety. It also contributes to regulating alertness and concentration.

Check out the following table for a list of the most common SNRIs available and the potential side effects for each one.

Potential Benefits and Side Effects of SNRIs
Generic Name Brand Name Average Adult Dose Potential Benefits Some Possible Side Effects*
Desvenlafaxine Pristiq 50 to 100 mg/day Antidepressant (approved for use in unipolar depression). Also
used to treat many anxiety disorders, but this can present
challenges in someone with bipolar disorder.
Suicidal ideation; agitation; disinhibition; mania; insomnia;
sedation; elevated blood pressure; change in sexual function;
nausea or diarrhea; weight gain.
Duloxetine Cymbalta 60 to 120 mg/day Antidepressant (approved for use in unipolar depression). Also
used to treat many anxiety disorders, but this can present
challenges in someone with bipolar disorder. Treats some pain
syndromes.
Suicidal ideation; agitation; disinhibition; mania; insomnia;
sedation; elevated blood pressure; change in sexual function;
nausea or diarrhea; weight gain; affects the liver, so alcohol
intake should be limited.
Venlafaxine Effexor
Effexor XR
75 to 375 mg/day; 75 to 225 mg/day (extended release) Antidepressant (approved for use in unipolar depression). Also
used to treat many anxiety disorders, but this can present
challenges in someone with bipolar disorder.
Suicidal ideation; agitation; disinhibition; mania; insomnia;
sedation; elevated blood pressure; change in sexual function;
nausea or diarrhea; weight gain; has severe withdrawal symptoms
with missed doses.

mg/day = milligrams per day.

* Other side effects may occur that arent listed.

SNRIs may take several weeks to become fully effective, so keep taking the medication even if you don’t experience immediate relief.