New Release: Alpha testing version has been released.

Paroxetine

N06A - Antidepressants ATC N06AB05 Small molecule approved 1992 Oral Black-box warning

JFDA label: Unirox

⚠ Black-Box Warning
  • Suicidality and antidepressant drugs:

Mechanism of Action

Paroxetine is a selective serotonin reuptake inhibitor, chemically unrelated to tricyclic, tetracyclic, or other antidepressants; presumably, the inhibition of serotonin reuptake from brain synapse stimulated serotonin activity in the brain

Indications

Approved

  • Generalized anxiety disorder (immediate release)
  • Major depressive disorder (immediate and controlled release)
  • Obsessive-compulsive disorder (immediate release)
  • Panic disorder (immediate and controlled release)
  • Post-traumatic stress disorder (immediate release)
  • Premenstrual dysphoric disorder (controlled release)
  • Social anxiety disorder (immediate and controlled release)
  • Vasomotor symptoms of menopause (Brisdelle only)

Off-label

  • Obsessive-compulsive disorder (children and adolescents)
  • Social anxiety disorder (children and adolescents)

Contraindications

Source: Lexicomp

  • Concurrent use with or within 14 days of MAOIs intended to treat psychiatric disorders Absolute
  • concomitant use with pimozide or thioridazine Absolute
  • hypersensitivity to paroxetine or any of its inactive ingredients Absolute
  • initiation in patients being treated with linezolid or methylene blue IV Absolute
  • pregnancy (Brisdelle only) Absolute

Adverse Reactions

Very Common >10%Common 1–10%Uncommon 0.1–1% Rare 0.01–0.1%Very Rare <0.01%Not Known

Cardiac disorders (5)

Common chest pain · hypertension · palpitations · tachycardia · Vasodilatation

Nervous system disorders (22)

Very Common Discontinuation syndrome (high risk) · dizziness · Drowsiness · headache · insomnia · Somnolence

Common abnormal dreams · agitation · amnesia · anxiety · chills · confusion · depersonalization · emotional lability · fatigue · lack of concentration · myasthenia · myoclonus · Nervousness · paresthesia · vertigo · yawning

Renal and urinary disorders (8)

Very Common Ejaculatory disorder

Common dysmenorrhea · female genital tract disease · impotence · Male genital disease · orgasm disturbance · urinary frequency · urinary tract infection

Metabolism and nutrition disorders (4)

Very Common Decreased libido

Common Weight gain · Weight gain

Rare Hyponatraemia (SIADH)

Gastrointestinal disorders (15)

Very Common Constipation · constipation · diarrhea · Dry mouth · Nausea · Nausea · xerostomia

Common abdominal pain · Decreased appetite · dysgeusia · dyspepsia · flatulence · increased appetite · nausea and vomiting · vomiting

Skin and subcutaneous tissue disorders (3)

Very Common Diaphoresis

Common pruritus · Skin rash

Musculoskeletal and connective tissue disorders (6)

Very Common tremor · Weakness

Common arthralgia · back pain · Myalgia · myopathy

Eye disorders (2)

Common Blurred vision · visual disturbance

Ear and labyrinth disorders (1)

Common Tinnitus

Reproductive system and breast disorders (1)

Very Common Sexual dysfunction

Infections and infestations (1)

Common Infection

Respiratory, thoracic and mediastinal disorders (4)

Common Dyspnea · pharyngitis · rhinitis · sinusitis

Dosing

Source: Lexicomp

Major depressive disorder (MDD): Oral: Paxil, Pexeva: Initial: 20 mg once daily, preferably in the morning; increase if needed by 10 mg/day increments at intervals of at least 1 week; maximum dose: 50 mg/day Paxil CR: Initial: 25 mg once daily; increase if needed by 12.5 mg/day increments at intervals of at least 1 week; maximum dose: 62.5 mg/day Generalized anxiety disorder (GAD) (Paxil, Pexeva): Oral: Initial: 20 mg once daily, preferably in the morning (if dose is increased, adjust in increments of 10 mg/day at 1-week intervals); doses of 20 to 50 mg/day were used in clinical trials, however, no greater benefit was seen with doses >20 mg. Obsessive-compulsive disorder (OCD) (Paxil, Pexeva): Oral: Initial: 20 mg once daily, preferably in the morning; increase if needed by 10 mg/day increments at intervals of at least 1 week; recommended dose: 40 mg/day; range: 20 to 60 mg/day; maximum dose: 60 mg/day Panic disorder: Oral: Paxil, Pexeva: Initial: 10 mg once daily, preferably in the morning; increase if needed by 10 mg/day increments at intervals of at least 1 week; recommended dose: 40 mg/day; range: 10 to 60 mg/day; maximum dose: 60 mg/day Paxil CR: Initial: 12.5 mg once daily; increase if needed by 12.5 mg/day at intervals of at least 1 week; maximum dose: 75 mg/day Premenstrual dysphoric disorder (PMDD) (Paxil CR): Oral: Initial: 12.5 mg once daily in the morning; may be increased to 25 mg/day; dosing changes should occur at intervals of at least 1 week. May be given daily throughout the menstrual cycle or limited to the luteal phase. Post-traumatic stress disorder (PTSD) (Paxil): Oral: Initial: 20 mg once daily, preferably in the morning; increase if needed by 10 mg/day increments at intervals of at least 1 week; range: 20 to 50 mg. Limited data suggest doses of 40 mg/day were not more efficacious than 20 mg/day. Social anxiety disorder: Oral: Paxil: Initial: 20 mg once daily, preferably in the morning; recommended dose: 20 mg/day; range: 20 to 60 mg/day; doses >20 mg may not have additional benefit Paxil CR: Initial: 12.5 mg once daily, preferably in the morning; may be increased by 12.5 mg/day at intervals of at least 1 week; maximum dose: 37.5 mg/day Vasomotor symptoms of menopause: Brisdelle: 7.5 mg once daily at bedtime Paxil CR (off-label use): 12.5 to 25 mg once daily (Stearns 2003) Discontinuation of therapy: Upon discontinuation of antidepressant therapy, gradually taper the dose to minimize the incidence of withdrawal symptoms and allow for the detection of re-emerging symptoms. Evidence supporting ideal taper rates is limited. APA and NICE guidelines suggest tapering therapy over at least several weeks with consideration to the half-life of the antidepressant; antidepressants with a shorter half-life may need to be tapered more conservatively. In addition for long-term treated patients, WFSBP guidelines recommend tapering over 4 to 6 months. If intolerable withdrawal symptoms occur following a dose reduction, consider resuming the
(For additional information see "Paroxetine: Pediatric drug information") Obsessive-compulsive disorder (OCD) (off-label use): Children and Adolescents 7 to 17 years: Oral: Initial: 10 mg daily; may increase based on response and tolerability by 10 mg/day every 7 to 14 days to a maximum of 60 mg/day (Geller 2004; Rosenberg 1999). Social anxiety disorder (off-label use): Children and Adolescents 8 to 17 years: Oral: Initial: 10 mg once daily; increase based on response and tolerability by 10 mg/day at intervals of at least 7 days to a maximum of 50 mg/day (Wagner 2004). Discontinuation of therapy: Refer to adult dosing. MAO inhibitor recommendations: Refer to adult dosing.
Major depressive disorder (MDD), obsessive compulsive disorder (OCD), panic attack, social anxiety disorder: Paxil, Pexeva: Oral: Initial: 10 mg/day; increase if needed by 10 mg/day increments at intervals of at least 1 week; maximum dose: 40 mg/day Paxil CR: Initial: 12.5 mg/day; increase if needed by 12.5 mg/day increments at intervals of at least 1 week; maximum dose: 50 mg/day Discontinuation of therapy: Refer to adult dosing. MAO inhibitor recommendations: Refer to adult dosing.
Adults: Brisdelle: No dosage adjustment necessary. Paxil, Paxil CR, Pexeva: CrCl 30-60 mL/minute: Plasma concentration is 2 times that seen in normal function. There are no dosage adjustments provided in manufacturer's labeling. Severe impairment (CrCl Paxil, Pexeva: Initial: 10 mg/day; increase if needed by 10 mg/day increments at intervals of at least 1 week; maximum dose: 40 mg/day Paxil CR: Initial: 12.5 mg/day; increase if needed by 12.5 mg/day increments at intervals of at least 1 week; maximum dose: 50 mg/day
Adults: In hepatic dysfunction, plasma concentration is 2 times that seen in normal function. Brisdelle: No dosage adjustment necessary. Paxil, Paxil CR, Pexeva: Mild-to-moderate impairment: There are no dosage adjustments provided in manufacturer's labeling. Severe impairment: Paxil, Pexeva: Initial: 10 mg/day; increase if needed by 10 mg/day increments at intervals of at least 1 week; maximum dose: 40 mg/day Paxil CR: Initial: 12.5 mg/day; increase if needed by 12.5 mg/day increments at intervals of at least 1 week; maximum dose: 50 mg/day

Warnings & Precautions

Source: Lexicomp

Suicidal thinking/behavior

Antidepressants increase the risk of suicidal thinking and behavior in children, adolescents, and young adults (18 to 24 years of age) with major depressive disorder (MDD) and other psychiatric disorders; consider risk prior to prescribing. Short-term studies did not show an increased risk in patients >24 years of age and showed a decreased risk in patients ≥65 years. Closely monitor patients for clinical worsening, suicidality, or unusual changes in behavior, particularly during the initial 1 to 2 months of therapy or during periods of dosage adjustments (increases or decreases); the patient's family or caregiver should be instructed to closely observe the patient and communicate condition with healthcare provider. A medication guide concerning the use of antidepressants should be dispensed with each prescription. Paroxetine is not FDA approved for use in children.

Akathisia

Inability to remain still due to feelings of agitation or restlessness has been observed with paroxetine and other SSRIs. Usually occurs within the first few weeks of therapy.

Anticholinergic effects

Has low potential for sedation and anticholinergic effects relative to cyclic antidepressants; however among the SSRI class these effects are relatively higher.

Bleeding risk

May impair platelet aggregation resulting in increased risk of bleeding events, particularly if used concomitantly with aspirin, NSAIDs, warfarin or other anticoagulants. Bleeding related to SSRI use has been reported to range from relatively minor bruising and epistaxis to life-threatening hemorrhage.

CNS depression

May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks that require mental alertness (eg, operating machinery or driving).

Fractures

Bone fractures have been associated with antidepressant treatment. Consider the possibility of a fragility fracture if an antidepressant-treated patient presents with unexplained bone pain, point tenderness, swelling, or bruising (Rabenda 2013; Rizzoli, 2012).

Ocular effects

May cause mild pupillary dilation, which can lead to an episode of narrow-angle glaucoma in susceptible individuals. Consider evaluating patients who have not had an iridectomy for narrow-angle glaucoma risk factors.

Serotonin syndrome

Potentially life-threatening serotonin syndrome (SS) has occurred with serotonergic agents (eg, SSRIs, SNRIs), particularly when used in combination with other serotonergic agents (eg, triptans, TCAs, fentanyl, lithium, tramadol, buspirone, St John's wort, tryptophan) or agents that impair metabolism of serotonin (eg, MAO inhibitors intended to treat psychiatric disorders, other MAO inhibitors [ie, linezolid and intravenous methylene blue]). Monitor patients closely for signs of SS such as mental status changes (eg, agitation, hallucinations, delirium, coma); autonomic instability (eg, tachycardia, labile blood pressure, diaphoresis); neuromuscular changes (eg, tremor, rigidity, myoclonus); GI symptoms (eg, nausea, vomiting, diarrhea); and/or seizures. Discontinue treatment (and any concomitant serotonergic agent) immediately if signs/symptoms arise.

Sexual dysfunction

May cause or exacerbate sexual dysfunction.

SIADH and hyponatremia

SSRIs and SNRIs have been associated with the development of SIADH; hyponatremia has been reported rarely (including severe cases with serum sodium Disease-related concerns:

Cardiovascular disease

Use with caution in patients with cardiovascular disease; paroxetine has not been systemically evaluated in patients with a recent history of MI or unstable heart disease.

Hepatic impairment

Use with caution in patients with hepatic impairment; clearance is decreased and plasma concentrations are increased; a lower dosage may be needed.

Mania/hypomania

May worsen psychosis in some patients or precipitate a shift to mania or hypomania in patients with bipolar disorder. Monotherapy in patients with bipolar disorder should be avoided. Patients presenting with depressive symptoms should be screened for bipolar disorder. Paroxetine is not FDA approved for the treatment of bipolar depression.

Renal impairment

Use with caution in patients with renal impairment; clearance is decreased and plasma concentrations are increased; a lower dosage may be needed.

Seizure disorder

Use with caution in patients with a previous seizure disorder or condition predisposing to seizures such as brain damage or alcoholism. Concurrent drug therapy issues:

Drug-drug interactions

Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information. Dosage form specific issues:

Brisdelle

Brisdelle contains a lower dose than what is required for the treatment of psychiatric conditions. Patients who require paroxetine for the treatment of psychiatric conditions should discontinue Brisdelle and begin treatment with a paroxetine-containing medication which provides an adequate dosage.

Polysorbate 80

Some dosage forms may contain polysorbate 80 (also known as Tweens). Hypersensitivity reactions, usually a delayed reaction, have been reported following exposure to pharmaceutical products containing polysorbate 80 in certain individuals (Isaksson 2002; Lucente 2000; Shelley, 1995). Thrombocytopenia, ascites, pulmonary deterioration, and renal and hepatic failure have been reported in premature neonates after receiving parenteral products containing polysorbate 80 (Alade 1986; CDC 1984). See manufacturer's labeling. Other warnings/precautions:

Discontinuation syndrome

Abrupt discontinuation or interruption of antidepressant therapy has been associated with a discontinuation syndrome. Symptoms arising may vary with antidepressant however commonly include nausea, vomiting, diarrhea, headaches, lightheadedness, dizziness, diminished appetite, sweating, chills, tremors, paresthesias, fatigue, somnolence, and sleep disturbances (eg, vivid dreams, insomnia). Less common symptoms include electric shock-like sensations, cardiac arrhythmias (more common with tricyclic antidepressants), myalgias, parkinsonism, arthralgias, and balance difficulties. Psychological symptoms may also emerge such as agitation, anxiety, akathisia, panic attacks, irritability, aggressiveness, worsening of mood, dysphoria, mood lability, hyperactivity, mania/hypomania, depersonalization, decreased concentration, slowed thinking, confusion, and memory or concentration difficulties. Greater risks for developing a discontinuation syndrome have been associated with antidepressants with shorter half-lives, longer durations of treatment, and abrupt discontinuation. For antidepressants of short or intermediate half-lives, symptoms may emerge within 2 to 5 days after treatment discontinuation and last 7 to 14 days (APA 2010; Fava 2006; Haddod 2001; Shelton 2001; Warner 2006).

Electroconvulsive therapy

May increase the risks associated with electroconvulsive therapy; consider discontinuing, when possible, prior to ECT treatment.

Pregnancy & Lactation

Pregnancy

FDA category D Teratogenic

Avoid

Only SSRI classified D. Switch to sertraline preconception if possible. If already pregnant and stable, discussion with prescriber is essential — abrupt discontinuation may be more harmful

Lactation

RID 5.6%

Paroxetine is present in breast milk. The relative infant dose (RID) of paroxetine is 5.6% when calculated using the highest breast milk concentration located and compared to a weight-adjusted maternal dose of 50 mg/day. In general, breastfeeding is considered acceptable when the RID is The RID of paroxetine was calculated using a milk concentration of 255.3 ng/mL, providing an estimated daily infant dose via breast milk of 0.04 mg/kg/day. This milk concentration was obtained following mater

LactMed: monitor the infant.

Monitoring

Clinical pearlSerum sodium in at-risk populations (as clinically indicated); mental status for depression, suicide ideation (especially at the beginning of therapy or when doses are increased or decreased), anxiety, social functioning, mania, panic attacks; signs/symptoms of serotonin syndrome; akathisia

Chemistry & Properties

2D structure
FormulaC19H20FNO3
Molecular weight329.37 g/mol
IUPAC name(3S,4R)-3-(1,3-benzodioxol-5-yloxymethyl)-4-(4-fluorophenyl)piperidine
CAS61869-08-7
PubChem CID43815
InChIKeyAHOUBRCZNHFOSL-YOEHRIQHSA-N
logP3.33 (XLogP 3.5)
Polar surface area39.72 Ų
H-bond acceptors / donors4 / 1
Drug-likeness (QED)0.93
Lipinski violations0
SMILESFc1ccc([C@@H]2CCNC[C@H]2COc2ccc3c(c2)OCO3)cc1

Biology & Pharmacokinetics

Pharmacokinetics

BBB penetrantYes

Enzyme interactions

EnzymeRoleDetail
CYP1A2Inhibitor
CYP1A2Substrate
CYP2B6Inhibitor
CYP2C19Substrate
CYP2D6Inhibitor Ki 4.849999999999998 µM
CYP2D6Substrate
CYP3A4Inhibitor IC₅₀ 20.000000000000004 µM
CYP3A4Substrate

Receptor binding (top 14)

TargetActionAffinity
SERT (SLC6A4) Inhibitor pKd 10.1
5-HT Transporter (SLC6A4) Binding pKi 9.7
SERT (SLC6A4) Inhibitor pKi 9.6
Cholinergic, muscarinic M3 (CHRM3) Binding pKi 7.1
Norepinephrine transporter Binding pKi 7.0
Cholinergic, muscarinic Binding pKi 7.0
Cholinergic, muscarinic M1 (CHRM1) Binding pKi 6.8
Cholinergic, muscarinic M4 (CHRM4) Binding pKi 6.5
Cholinergic, muscarinic M2 (CHRM2) Binding pKi 6.5
Dopamine Transporter (SLC6A3) Binding pKi 6.3
Cholinergic, muscarinic M5 (CHRM5) Binding pKi 6.2
adrenergic Alpha1A (ADRA1A) Binding pKi 6.0
adrenergic Alpha1 Binding pKi 5.6
adrenergic Alpha2 Binding pKi 5.4

Transporters

BCRP (Inhibitor)BSEP (Inhibitor)BSEP (Inhibitor)MDR1 (Inhibitor)MRP1 (Inhibitor)MRP2 (Inhibitor)MRP3 (Inhibitor)MRP4 (Inhibitor)OATP1B1 (Inhibitor)OATP1B1 (Inhibitor)OATP1B3 (Inhibitor)OATP1B3 (Inhibitor)OATP2B1 (Inhibitor)OCT1 (Inhibitor)P-gp (Inhibitor)MDR1 (Substrate)P-gp (Substrate)

Drug–drug interactions (100+, DDInter)

Interacting drugSeverityManagement
Astemizole major
Bupropion major
Dexfenfluramine major
Dextromethorphan major
Diethylpropion major
Dolasetron major
Doxepin major
Doxepin (topical) major
Eliglustat major
Fenfluramine major
Granisetron major
Iohexol major
Iopamidol major
Lorcaserin major
Mazindol major
Methylene blue major
Ondansetron major
Palonosetron major
Panobinostat major
Phentermine major
Phenylpropanolamine major
Procarbazine major
Sibutramine major
Tamoxifen major
Abciximab moderate
Abiraterone moderate
Acalabrutinib moderate
Acetohexamide moderate
Acetylsalicylic acid moderate
Aldesleukin moderate
Alimemazine moderate
Alteplase moderate
Anagrelide moderate
Anistreplase moderate
Antithrombin III human moderate
Apixaban moderate
Argatroban moderate
Azatadine moderate
Betrixaban moderate
Bivalirudin moderate

Showing 40 of 100+.

Registered Products (9)

BrandForm / strengthPackAgentCitizen (JOD)
Paroxat Tablet 20 mg 20 tab The Jordan Drugstore Co 3.380
Paxitab Tablet 20 mg 30 tab Sukhtian Group 5.170
Unirox Tablet 20 mg 30 tab UNITED PHARM.MFG.CO.LTD(UPM)/JORDAN 6.330
Paroxat Tablet 40 mg 20 tab The Jordan Drugstore Co 6.360
Seroxat Tab Tablet 20 mg 30 tab Suleiman Tannous & Sons Co. Ltd 7.060
Xalexa Tablet 20 mg 30 tab AL Rahma Drug Store 7.370
Paxitab Tablet 40 mg 30 tab Sukhtian Group 8.480
Seroxat CR Tablet 12.5 mg 30 tab Suleiman Tannous & Sons Co. Ltd 9.180
Xalexa Tablet 30 mg 30 tab AL Rahma Drug Store 11.060