Is paroxetine (selective serotonin reuptake inhibitor) associated with diarrhea?

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From the Guidelines

Paroxetine can cause diarrhea as a side effect, particularly during the first few weeks of treatment or when discontinuing the medication, as reported in a discontinuation syndrome characterized by various symptoms including diarrhea 1. This occurs in patients taking the medication, and the exact percentage is not specified in the provided evidence. If you're experiencing diarrhea while on paroxetine, don't stop the medication abruptly, but consult your healthcare provider. For mild diarrhea, staying hydrated, eating bland foods, and avoiding dairy or spicy foods may help. The diarrhea often improves within 1-2 weeks as your body adjusts to the medication. Some key points to consider when taking paroxetine include:

  • Taking paroxetine with food might reduce gastrointestinal side effects
  • The therapeutic benefits of paroxetine typically take 2-4 weeks to appear, so some temporary side effects may be worth tolerating if the medication is otherwise helping your condition
  • If diarrhea is severe, persistent, or accompanied by fever or blood, contact your doctor immediately as they may recommend temporarily reducing your dose, switching to a different SSRI, or prescribing an anti-diarrheal medication
  • Paroxetine causes diarrhea by increasing serotonin levels in the gut, which can accelerate intestinal movement, as suggested by its association with serotonin syndrome when combined with monoamine oxidase inhibitors (MAOIs) 1. It's also important to note that paroxetine has been associated with a discontinuation syndrome, which includes symptoms such as diarrhea, nausea, vomiting, and insomnia, when the medication is stopped abruptly or the dose is reduced too quickly 1. In terms of management, a conservative approach to prescribing paroxetine, including starting with a low dose and gradually increasing as tolerated, may help minimize the risk of adverse effects, including diarrhea 1.

From the FDA Drug Label

The most commonly observed adverse events associated with the use of paroxetine (incidence of 5% or greater and incidence for PAXIL at least twice that for placebo, derived from Table 4) were: Asthenia, sweating, nausea, dry mouth, diarrhea, decreased appetite, somnolence, libido decreased, abnormal ejaculation, female genital disorders, and impotence

  • Diarrhea is listed as a commonly observed adverse event in patients with Posttraumatic Stress Disorder with an incidence of 5% or greater.
  • The incidence of diarrhea in patients treated with paroxetine is 1.0% in major depressive disorder, which is not greater than or equal to 2 times the incidence of placebo.
  • Diarrhea is also mentioned in the table for adverse events associated with discontinuation of treatment, with an incidence of 1.0% in patients treated with PAXIL, compared to 0.3% in patients treated with placebo 2.
  • Based on the information provided, paroxetine may be associated with an increased risk of diarrhea in some patients, particularly those with Posttraumatic Stress Disorder.

From the Research

Paroxetine and Diarrhea

  • Paroxetine is a selective serotonin reuptake inhibitor (SSRI) that is used to treat depression, obsessive-compulsive disorder, panic disorder, and social phobia 3.
  • Common side effects of paroxetine include nausea, diarrhea, insomnia, dry mouth, and nervousness 4.
  • Diarrhea is a potential side effect of paroxetine, with studies suggesting that it is one of the most common gastrointestinal side effects associated with the medication 5, 4.
  • The exact mechanism by which paroxetine causes diarrhea is not fully understood, but it is thought to be related to its effects on the serotonin system in the gut 5.
  • Other medications, such as loperamide, bile acid sequestrants, and antispasmodics, are available to treat diarrhea-predominant irritable bowel syndrome (IBS-D), but paroxetine is not typically used for this purpose 6.
  • In general, paroxetine is well-tolerated and effective in the treatment of depression and anxiety disorders, but patients should be monitored for potential side effects, including diarrhea 3, 7.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Paroxetine: a review.

CNS drug reviews, 2001

Research

An overview of paroxetine.

The Journal of clinical psychiatry, 1992

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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