Paroxetine is a selective serotonin-reuptake inhibitor (SSRI) type of antidepressant. Paroxetine tablets, suspension, and extended-release tablets are used to treat depression, panic disorder, and social anxiety disorder. Paroxetine tablets and suspension also are used to treat obsessive-compulsive disorder, generalized anxiety disorder, and post-traumatic stress disorder. SSRIs and antidepressants in general have been evaluated for use in treating pain and peripheral neuropathy. Paroxetine specifically has been studied in patients with cancer for hot flashes, sleep-wake disturbances, and fatigue.

Paroxetine is an SSRI antidepressant that is a strong inhibitor of the CYP2D6 enzyme system that acts to metabolize tamoxifen to its active form, endoxifen. A retrospective study of women with breast cancer taking tamoxifen and paroxetine showed a significantly increased risk of death from breast cancer with overlapping use of both agents. Caution is recommended in the use of paroxetine for women experiencing tamoxifen-induced hot flashes.