Description

Simple

A medication used to treat depression, anxiety, OCD, and PTSD, as well as the symptoms of menopause such as hot flashes.

Clinical

A selective serotonin reuptake inhibitor used to treat major depressive disorder, panic disorder, OCD, social phobia, generalized anxiety disorder, the vasomotor symptoms of menopause, and premenstrual dysphoric disorder.

Overview

Paroxetine is a selective serotonin reuptake inhibitor (SSRI) drug commonly known as Paxil. It has a variety of uses, including the treatment of anxiety disorders, major depression, posttraumatic stress disorder, and symptoms of menopause, among others.[26] It was approved by the FDA in the early 1990s and marketed by SmithKline Beecham.[32,33] A unique feature of this drug is that it is highly potent and selective in its inhibition of serotonin reuptake and has little effect on other neurotransmitters.[13] Because of its potent inhibition of serotonin reuptake, paroxetine is more likely to cause withdrawal effects upon cessation. Paroxetine is well tolerated in most patients with a similar adverse effect profile to other members of its drug class.[Read more

Pharmacology

Indication

Paroxetine is indicated for the management of depression, obsessive-compulsive disorder, panic disorder, social anxiety disorder, generalized anxiety disorder, posttraumatic stress disorder.[29] One form of paroxetine,... Read more

Pharmacodynamic

Paroxetine treats the symptoms of depression, various anxiety disorders, posttraumatic stress disorder, obsessive-compulsive disorder, and the vasomotor symptoms of menopause via the inhibition of serotonin reuptake.[ Read more

Mechanism of action

Paroxetine enhances serotonergic activity via the inhibition presynaptic reuptake of serotonin by the serotonin (SERT) receptor.[ Read more

Absorption

Paroxetine is readily absorbed from the gastrointestinal tract. Due to the first-pass metabolism, the bioavailability ranges from 30-60%. Cmax is attained 2 to 8 hours after an oral dose.[ Read more

Protein binding

Paroxetine is 95% bound to plasma proteins.[7, Read more

Volume of distribution

Paroxetine has a large volume of distribution and is found throughout the body, including in the central nervous system. Only 1% of the drug is found in the plasma.[29]Paroxetine is found in the breast milk at concent... Read more

Clearance

The apparent oral clearance of paroxetine is 167 L/h.[14] The clearance... Read more

Half life

The mean elimination half-life of paroxetine is about 21 hours.[29] In healthy young subjects, mean elimination half-life was found to be 17.3 hours.[ Read more

Route of elimination

About 2/3 of a single paroxetine dose is found to be excreted in the urine and the remainder is found to be excreted in feces. Almost all of the dose is eliminated as metabolites; 3% is found to be excreted as unchanged paroxetine.[ Read more

Toxicity


The acute LD50 in mice and rats is 350 mg/kg.[35]

Overdose information

The lowest dose of paroxetine reported to lead to a fatal outcome is approximately 400 mg. The largest reported paroxetine overdose fr... Read more

Adverse Effects

Effect Regions Age Groups Incidences Evidence Type
Ejaculation disorder US
  • Kind: experimental
    • Percent: 28%
  • Kind: placebo
    • Percent: 1%
  • Clinical Trial
    Abnormal ejaculation US
  • Kind: experimental
    • Percent: 28%
  • Kind: placebo
    • Percent: 1%
  • Clinical Trial
    Abnormal ejaculation US
  • Kind: experimental
    • Percent: 27%
  • Kind: placebo
    • Percent: 3%
  • Clinical Trial
    Anorgasmia US
  • Kind: experimental
    • Percent: 27%
  • Kind: placebo
    • Percent: 3%
  • Clinical Trial
    Delayed ejaculation US
  • Kind: experimental
    • Percent: 27%
  • Kind: placebo
    • Percent: 3%
  • Clinical Trial
    Headache US
  • Kind: experimental
    • Percent: 27%
  • Kind: placebo
    • Percent: 20%
  • Clinical Trial
    Delayed ejaculation US
  • Kind: experimental
    • Percent: 26%
  • Kind: placebo
    • Percent: 1%
  • Clinical Trial
    Abnormal ejaculation US
  • Kind: experimental
    • Percent: 26%
  • Kind: placebo
    • Percent: 1%
  • Clinical Trial
    Anorgasmia US
  • Kind: experimental
    • Percent: 26%
  • Kind: placebo
    • Percent: 1%
  • Clinical Trial
    Nausea US
  • Kind: experimental
    • Percent: 26%
  • Kind: placebo
    • Percent: 9%
  • Clinical Trial
    Nausea US
  • Kind: experimental
    • Percent: 25%
  • Kind: placebo
    • Percent: 7%
  • Clinical Trial
    Abnormal ejaculation US
  • Kind: experimental
    • Percent: 25%
  • Kind: placebo
    • Percent: 2%
  • Clinical Trial
    Nausea US
  • Kind: experimental
    • Percent: 25%
  • Kind: placebo
    • Percent: 7%
  • Clinical Trial
    Somnolence US
  • Kind: experimental
    • Percent: 7%
  • Kind: experimental
    • Percent: 24%
  • Clinical Trial
    Insomnia US
  • Kind: experimental
    • Percent: 13%
  • Kind: experimental
    • Percent: 24%
  • Clinical Trial
    Somnolence US
  • Kind: experimental
    • Percent: 24%
  • Kind: placebo
    • Percent: 7%
  • Clinical Trial
    Insomnia US
  • Kind: experimental
    • Percent: 24%
  • Kind: placebo
    • Percent: 13%
  • Clinical Trial
    Nausea US
  • Kind: experimental
    • Percent: 23%
  • Kind: placebo
    • Percent: 17%
  • Clinical Trial
    Ejaculation disorder US
  • Kind: experimental
    • Percent: 23%
  • Kind: experimental
    • Percent: 1%
  • Clinical Trial
    Nausea US
  • Kind: experimental
    • Percent: 10%
  • Kind: experimental
    • Percent: 23%
  • Clinical Trial
    Nausea US
  • Kind: experimental
    • Percent: 23%
  • Kind: placebo
    • Percent: 17%
  • Clinical Trial
    Headache US
    • adult
  • Kind: experimental
    • Percent: 23%
  • Kind: placebo
    • Percent: 17%
  • Clinical Trial
    Nausea US
  • Kind: experimental
    • Percent: 23%
  • Kind: placebo
    • Percent: 17%
  • Clinical Trial
    Abnormal ejaculation US
  • Kind: experimental
    • Percent: 23%
  • Kind: placebo
    • Percent: 1%
  • Clinical Trial
    Nausea US
  • Kind: experimental
    • Percent: 23%
  • Kind: placebo
    • Percent: 10%
  • Clinical Trial
    Somnolence US
  • Kind: experimental
    • Percent: 23%
  • Kind: placebo
    • Percent: 9%
  • Clinical Trial
    Somnolence US
  • Kind: experimental
    • Percent: 22%
  • Kind: placebo
    • Percent: 5%
  • Clinical Trial
    Asthenia US
  • Kind: experimental
    • Percent: 22%
  • Kind: placebo
    • Percent: 14%
  • Clinical Trial
    Asthenia US
  • Kind: experimental
    • Percent: 22%
  • Kind: experimental
    • Percent: 14%
  • Clinical Trial
    Nausea US
    • adult
  • Kind: experimental
    • Percent: 22%
  • Kind: placebo
    • Percent: 6%
  • Clinical Trial
    Nausea US
  • Kind: experimental
    • Percent: 22%
  • Kind: placebo
    • Percent: 10%
  • Clinical Trial
    Somnolence US
  • Kind: experimental
    • Percent: 22%
  • Kind: placebo
    • Percent: 8%
  • Clinical Trial
    Somnolence US
  • Kind: experimental
    • Percent: 22%
  • Kind: placebo
    • Percent: 5%
  • Clinical Trial
    Asthenia US
  • Kind: experimental
    • Percent: 22%
  • Kind: placebo
    • Percent: 14%
  • Clinical Trial
    Asthenia US
  • Kind: experimental
    • Percent: 22%
  • Kind: placebo
    • Percent: 14%
  • Clinical Trial
    Insomnia US
  • Kind: experimental
    • Percent: 21%
  • Kind: placebo
    • Percent: 16%
  • Clinical Trial
    Ejaculation disorder US
  • Kind: experimental
    • Percent: 21%
  • Kind: placebo
    • Percent: 1%
  • Clinical Trial
    Somnolence US
  • Kind: experimental
    • Percent: 21%
  • Kind: placebo
    • Percent: 12%
  • Clinical Trial
    Abnormal ejaculation US
  • Kind: experimental
    • Percent: 21%
  • Kind: placebo
    • Percent: 1%
  • Clinical Trial
    Insomnia US
  • Kind: experimental
    • Percent: 21%
  • Kind: placebo
    • Percent: 16%
  • Clinical Trial
    Insomnia US
  • Kind: experimental
    • Percent: 20%
  • Kind: placebo
    • Percent: 11%
  • Clinical Trial
    Somnolence US
  • Kind: experimental
    • Percent: 20%
  • Kind: placebo
    • Percent: 9%
  • Clinical Trial
    Nausea US
  • Kind: experimental
    • Percent: 20%
  • Kind: placebo
    • Percent: 5%
  • Clinical Trial
    Somnolence US
  • Kind: experimental
    • Percent: 19%
  • Kind: placebo
    • Percent: 11%
  • Clinical Trial
    Somnolence US
  • Kind: experimental
    • Percent: 19%
  • Kind: placebo
    • Percent: 11%
  • Clinical Trial
    Insomnia US
  • Kind: experimental
    • Percent: 18%
  • Kind: placebo
    • Percent: 10%
  • Clinical Trial
    Dry Mouth US
  • Kind: experimental
    • Percent: 18%
  • Kind: placebo
    • Percent: 11%
  • Clinical Trial
    Dry Mouth US
  • Kind: experimental
    • Percent: 9%
  • Kind: experimental
    • Percent: 18%
  • Clinical Trial
    Nausea US
  • Kind: experimental
    • Percent: 17-18%
  • Kind: placebo
    • Percent: 2-7%
  • Clinical Trial
    Diarrhea US
  • Kind: experimental
    • Percent: 18%
  • Kind: placebo
    • Percent: 7%
  • Clinical Trial

    Contraindications

    • Route:
      • Oral
    • Recommended Actions:
      • Avoid intravenous administration of methylene blue.
    • Regions: US
    • With Drugs:
        • Name: Methylene blue
        • Drugbank Id: DB09241
    • Route:
      • Oral
    • Dose Form:
      • Capsule
    • Regions: US
    • Patient Conditions:
        • Name: Pregnancy
        • Drugbank Id: DBCOND0018394
    • Route:
      • Oral
    • Regions: US
    • With Drugs:
        • Name: Thioridazine
        • Drugbank Id: DB00679
    • Route:
      • Oral
    • Regions: US
    • With Drugs:
        • Name: Pimozide
        • Drugbank Id: DB01100
    • Route:
      • Oral
    • Recommended Actions:
      • Do not administer within 14 days of MAO inhibitors
      • Do not administer with MAO inhibitors
    • Regions: US
    • Patient Conditions Associated With:
        • Name: Serotonin Syndrome
        • Drugbank Id: DBCOND0005988
    • With Categories:
        • Name: Monoamine Oxidase Inhibitors
        • Drugbank Id: DBCAT001004
        • Mesh Id: D008996
    • Route:
      • Oral
    • Hypersensitivity:
      • true
    • Regions: US

    Food Interactions

    Avoid alcohol.

    Take with or without food. Food does not significantly affect absorption.