Paroxetine is an antidepressant in the selective serotonin reuptake inhibitor (SSRI) family often encountered under brand names such as Paxil. It works mainly by increasing serotonin availability in the brain, which can improve mood and reduce anxiety over several weeks. For official dosing guidance and safety information see the prescribing information.

Common uses

Clinically, paroxetine is prescribed for a range of mood and anxiety conditions. Typical indications include:

  • Major depressive disorder
  • Generalized anxiety disorder and panic disorder
  • Social anxiety disorder and obsessive–compulsive disorder (OCD)
  • Post-traumatic stress disorder (PTSD) and premenstrual dysphoric disorder (PMDD)

It is one of several SSRI options; for information about the drug class see SSRIs. For clinical context about depressive illness, consult resources on depression.

Side effects and notable reactions

Common adverse effects include nausea, dry mouth, constipation, drowsiness or sleep changes, sweating, tremor and sexual dysfunction. Insomnia or sleep disturbance is reported by some patients; more on sleep effects appears at insomnia resources. Paroxetine has stronger anticholinergic activity than several other SSRIs, which can increase some side effects.

Safety, interactions and discontinuation

Serious but less frequent hazards include serotonin syndrome when combined with other serotonergic agents, and interactions due to paroxetine's inhibition of the CYP2D6 enzyme. There is a boxed warning for increased risk of suicidal thoughts in younger people; pregnancy and breastfeeding require specialist discussion because of possible risks. Stopping paroxetine abruptly commonly causes a discontinuation syndrome; gradual tapering under medical supervision is recommended.

Prescribers choose paroxetine based on the condition being treated, individual patient factors and prior response to medications. It is often used alongside psychotherapy, and alternatives within the SSRI family or other antidepressant classes are considered when side effects, interactions, pregnancy or withdrawal risk make it less suitable.