What to Expect When Starting Paroxetine
Medical Disclaimer: This content is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider before starting, stopping, or changing any medication. Using this site does not create a doctor-patient relationship.
Drug information changes as the FDA updates labeling, and we cannot guarantee it is complete or current. Verify critical details with your pharmacist or physician.
Emergencies: If you think you may have a medical emergency, call 911 immediately. For a suspected overdose, call Poison Control at 1-800-222-1222. Report side effects to the FDA MedWatch program at fda.gov/medwatch or 1-800-FDA-1088.
See our Terms of Use and Editorial Policy.
Introduction
Paroxetine (Paxil) is a selective serotonin reuptake inhibitor (SSRI) approved for depression, generalized anxiety disorder, panic disorder, social anxiety disorder, PTSD, and OCD. It works by blocking serotonin reuptake, increasing serotonin availability in the brain. Among SSRIs, paroxetine is notably more sedating and anticholinergic, and has the most significant discontinuation syndrome if stopped abruptly.
Week-by-week timeline
Starting at Low Dose
Paroxetine is started at 10-20 mg daily, typically taken in the morning with food. Common early side effects include nausea, drowsiness, dry mouth, constipation, and sexual side effects. Anxiety may transiently worsen in the first 1-2 weeks in patients with anxiety disorders.
Side Effect Adjustment
Nausea, drowsiness, and other side effects typically improve significantly by week 2-3. Sexual side effects (reduced libido, delayed orgasm) often persist throughout treatment. Antidepressant or anxiolytic effect has not yet peaked.
Therapeutic Effect Emerging
Mood, anxiety, and overall functioning begin to improve noticeably. Dose may be increased if response is insufficient. Most patients see meaningful improvement by 6 weeks.
Full Therapeutic Benefit
Maximum antidepressant and anxiolytic effect typically achieved. Continue medication for at least 6-12 months after remission to prevent relapse. Do not stop abruptly — paroxetine has the most pronounced discontinuation syndrome of all SSRIs.
Long-Term Continuation
Long-term use is appropriate for recurrent depression or chronic anxiety disorders. When discontinuing, work with your doctor on a very gradual taper, often over several months.
When to call your doctor
Contact your healthcare provider if you experience:
- Thoughts of self-harm or suicide, especially in the first 4 weeks of treatment or after dose changes
- Signs of serotonin syndrome: agitation, confusion, rapid heart rate, high fever, muscle stiffness
- Severe allergic reaction: rash, hives, difficulty breathing
- Manic or hypomanic symptoms: extremely elevated mood, decreased sleep need, racing thoughts
- Seizures
- Unusual bleeding or bruising
Tips for getting started
Take paroxetine at the same time each day, with food to minimize nausea. Never stop paroxetine abruptly — even a few missed doses can cause discontinuation syndrome (dizziness, electric shock sensations, irritability, flu-like symptoms). If you want to stop, work with your doctor on a very gradual taper plan. Limit alcohol as it interacts with SSRIs. Report sexual side effects to your doctor as dose adjustment or switching may help.
Frequently asked questions
More about Paroxetine
References
- [Regulatory] FDA Prescribing Information for Paxil (paroxetine) https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/020031s072lbl.pdf Accessed 2026-03-01.
- [Regulatory] NIH MedlinePlus: Paroxetine https://medlineplus.gov/druginfo/meds/a698032.html Accessed 2026-03-01.
- [Regulatory] NIMH Depression: Treatment Options https://www.nimh.nih.gov/health/topics/depression Accessed 2026-03-01.
Written and fact-checked by PrescriptionDrugs.org Editorial Team
Last updated: