paroxetine

Adjunctive therapy

Brands: Paxil, Paxil CR

Last reviewed 2025-10-05

Reviewed by PsychMed Editorial Team.

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Quick answers

What is paroxetine?
Paroxetine (Paxil) is an SSRI used across mood and anxiety disorders but notable for anticholinergic burden, weight gain, and discontinuation syndrome.
What is Paxil?
Paxil is a brand name for paroxetine (other brands: Paxil CR).
What is Paxil (paroxetine) used for?
Label indications include: Major depressive disorder; obsessive-compulsive disorder; panic disorder; social anxiety disorder; generalized anxiety disorder; posttraumatic stress disorder; premenstrual dysphoric disorder.
What drug class is Paxil (paroxetine)?
Selective serotonin reuptake inhibitor (SSRI).
What strengths does Paxil (paroxetine) come in?
Immediate-release tablets 10–40 mg; controlled-release tablets 12.5–37.5 mg; oral suspension 10 mg/5 mL.

Snapshot

Class: Adjunctive therapy
Common US brands: Paxil, Paxil CR
Therapeutic drug monitoring not routinely recommended.
Last reviewed: 2025-10-05

Label indications

Major depressive disorder; obsessive-compulsive disorder; panic disorder; social anxiety disorder; generalized anxiety disorder; posttraumatic stress disorder; premenstrual dysphoric disorder.

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Clinical Highlights

Paroxetine (Paxil) is an SSRI used across mood and anxiety disorders but notable for anticholinergic burden, weight gain, and discontinuation syndrome. Potent CYP2D6 inhibition requires careful coordination with other psychotropics.

Anticholinergic effects (dry mouth, constipation, sedation) can be clinically significant; alternatives are often preferred in older adults or patients vulnerable to delirium and falls.
Perinatal planning matters: paroxetine has less favorable pregnancy data than some SSRIs, so alternatives are often preferred when feasible.
Compared with many SSRIs, paroxetine is more likely to cause discontinuation symptoms if stopped abruptly; tapering plans and clear follow-up reduce rebound anxiety and dizziness.
The compare view to balance anticholinergic load, discontinuation risk, and interactions, and the Paroxetine evidence feed can help contextualize regimen switches.
Major depressive disorder (FDA 1992)
Panic disorder (FDA 1996)
Post-traumatic stress disorder (FDA 2001)

Dosing & Formulations

Immediate-release tablets 10–40 mg; controlled-release tablets 12.5–37.5 mg; oral suspension 10 mg/5 mL. Start 20 mg once daily (morning); titrate by 10 mg weekly to 20–50 mg/day (IR).

Controlled-release: start 25 mg daily; increase to 37.5–62.5 mg/day as needed.
Taper by 10 mg every 1–2 weeks to mitigate discontinuation symptoms.

Monitoring & Risks

Boxed warning: Antidepressants increase suicidality risk in young adults; monitor closely during initiation. Sedation: bedtime dosing can reduce daytime drowsiness for some patients.

Dry mouth & constipation: hydration, saliva substitutes, and bowel regimen planning may help.
Sexual dysfunction: Discuss expectations and management options.
Weight gain: monitoring BMI and using diet/activity supports can help.
Sweating: Hydration and clothing adjustments may help.
Discontinuation symptoms can be prominent (dizziness, “electric shock” sensations, irritability); tapering is typically gradual because abrupt stoppage can worsen symptoms.
Hyponatremia can occur, particularly in older adults or diuretic users; serum sodium is often checked when symptoms (confusion, fatigue) appear.

Drug Interactions

Potent CYP2D6 inhibitor—adjust doses of TCAs, antipsychotics, tamoxifen, beta-blockers. Contraindicated with MAOIs; observe 14-day washout when switching.

Additive serotonergic toxicity with triptans, SNRIs, linezolid, St. John’s wort.

Practice Notes

Baseline weight and metabolic labs are commonly tracked; alternatives may be preferred for patients at high metabolic risk. Use cautiously in hepatic impairment and older adults due to anticholinergic effects.

Screen for bipolar spectrum symptoms—paroxetine can precipitate mania/hypomania; coordinate care with the bipolar disorder hub when activation appears.
Discuss pregnancy planning and contraception; when treatment is needed in pregnancy, consider alternatives with more favorable perinatal safety profiles when feasible.
When CYP2D6 interactions are likely (polypharmacy, antipsychotics, TCAs), document the interaction plan and consider alternatives with fewer metabolic liabilities.
Anticholinergic burden can worsen constipation and cognitive clouding; consider comorbidities (BPH, fall risk) and polypharmacy when choosing among SSRIs overall.

References

Paxil (paroxetine) prescribing information — DailyMed (2025)
APA Clinical Practice Guideline for the Treatment of Depression — American Psychiatric Association (2023)Guidelinedepressionclinical
CANMAT 2024 Clinical Guidelines for Major Depressive Disorder — Canadian Journal of Psychiatry (2024)