Brand name: Paxil; Paxil CR; Brisdelle
Drug class: Selective Serotonin-reuptake Inhibitors

Medically reviewed by Drugs.com on May 10, 2025. Written by ASHP.

Introduction

Antidepressant; selective serotonin-reuptake inhibitor (SSRI).

Uses for PARoxetine

Major Depressive Disorder

Management of major depressive disorder in adults (paroxetine hydrochloride only).

Guidelines from the American Psychiatric Association (APA) and the Department of Veterans Affairs/Department of Defense state that there is no evidence to suggest superiority of one first-line antidepressant over another. Recommended first-line agents for initial treatment of major depressive disorder include bupropion, mirtazapine, an SSRI, an SNRI, trazodone, vilazodone, or vortioxetine. Select an initial antidepressant for treatment based on the following factors: patient preference; nature of prior response to medication; safety, tolerability, and anticipated adverse effects; concurrent psychiatric and medical conditions; specific properties of the medication; and cost.

Obsessive-Compulsive Disorder (OCD)

Immediate-release formulations of paroxetine hydrochloride used for management of OCD in adults; has also been used in pediatric patients ≥7 years of age^{† [off-label]} .

Legacy practice guidelines from APA list cognitive behavioral therapy and pharmacotherapy as safe and effective first-line treatments; for pharmacotherapy, SSRIs (e.g., fluoxetine, fluvoxamine, paroxetine, sertraline) are first-line. All SSRIs are equally effective, but individual patient response is variable; when selecting an SSRI, consider safety and acceptability of particular side effects for the patient, potential drug interactions, past treatment response, and the presence of comorbid medical conditions. Updated guidelines from international experts list escitalopram, fluvoxamine, fluoxetine, paroxetine, and sertraline as first-line treatments for OCD in adults.

Panic Disorder

Management of panic disorder in adults (paroxetine hydrochloride only).

Legacy guidelines from APA state that SSRIs, SNRIs, TCAs, benzodiazepines, and cognitive behavioral therapy are effective. Evidence insufficient to recommend any intervention over others; base choice of initial therapy on patient preference, past treatment history, the presence of comorbid medical or psychiatric conditions, potential adverse effects, potential drug interactions, cost, and treatment availability. For patients who prefer to initiate pharmacological treatment, SSRIs and SNRIs are recommended first line. Updated guidelines from international experts state that first-line medications for panic disorder include citalopram, escitalopram, fluvoxamine, fluoxetine, paroxetine, sertraline, and venlafaxine.

Social Anxiety Disorder

Paroxetine hydrochloride used for management of social anxiety disorder in adults; has also been used in pediatric patients ≥8 years of age^{† [off-label]} .

International experts state that escitalopram, fluvoxamine, paroxetine, sertraline, and venlafaxine are recommended first-line agents for pharmacological treatment of social anxiety disorder in adults.

Generalized Anxiety Disorders

Management of generalized anxiety disorder in adults (immediate release formulations of paroxetine hydrochloride only).

International experts state that the SSRIs escitalopram, paroxetine, and sertraline, as well as the SNRIs venlafaxine and duloxetine, are first-line treatments for generalized anxiety disorder.

Posttraumatic Stress Disorder (PTSD)

Management of PTSD in adults (immediate-release formulations of paroxetine hydrochloride only).

Legacy guidelines from APA state that selection of a specific treatment strategy will depend on patient-specific factors (e.g., age, gender, history, comorbid medical and psychiatric conditions, propensity for aggression or self-harm). SSRIs (i.e., fluoxetine, sertraline, paroxetine) are first-line treatments of choice for PTSD.

The Department of Veterans Affairs and Department of Defense recommend specific types of psychotherapy (e.g., cognitive processing therapy, eye movement desensitization and reprocessing, prolonged exposure therapy) over pharmacologic interventions for PTSD. If pharmacologic therapy is used, paroxetine, sertraline, or venlafaxine is recommended.

Premenstrual Dysphoric Disorder (PMDD)

Management of PMDD in adults (extended-release paroxetine hydrochloride only).

American College of Obstetricians and Gynecologists (ACOG) recommends SSRIs for management of affective premenstrual symptoms; SSRIs with evidence to support use in PMDD include sertraline, paroxetine, and fluoxetine. May administer SSRIs continuously or intermittently (i.e., during the luteal phase).

Vasomotor Symptoms Due to Menopause

Treatment of moderate to severe vasomotor symptoms associated with menopause (paroxetine mesylate capsules only).

In general, systemic hormone therapy with estrogen alone or estrogen in combination with progestin is the most effective therapy for vasomotor symptoms related to menopause. For women who cannot or choose not to take systemic hormone therapy, effective nonhormonal alternatives include SSRIs (including paroxetine), SNRIs, gabapentin, and fezolinetant.

Premature Ejaculation

Has been used for the management of premature ejaculation^{† [off-label]}.

Bipolar Disorder

Has been used adjunctively for short-term management of acute depressive episodes in patients with bipolar disorder^{† [off-label]}; not recommended first line, reserve for use in patients with inadequate response to first-line agents.

PARoxetine Dosage and Administration

General

Pretreatment Screening

• Screen for a personal or family history of bipolar disorder, mania, or hypomania.

• Review current medications to evaluate for risk of serious drug interactions.

• Screen for recent monoamine oxidase inhibitor (MAOI) use; at least 14 days must elapse between discontinuation of an MAOI and initiation of paroxetine.

• Inquire about baseline sexual function.

• Obtain pregnancy status.

Patient Monitoring

• Monitor for any indication of clinical worsening of depression and emergence of suicidal thoughts and behaviors.

• Monitor for emergence of symptoms of serotonin syndrome such as mental status changes, autonomic instability, neuromuscular symptoms, seizures and/or GI symptoms.

• Monitor for changes in sexual function.

• Monitor for pregnancy in female patients.

• Monitor for bleeding events in patients taking concomitant aspirin, nonsteroidal anti-inflammatory agents (NSAIAs), antiplatelet drugs, warfarin, or other anticoagulants. Monitor INR in patients taking concomitant warfarin.

Other General Considerations

• Adverse reactions may occur upon discontinuation. Do not discontinue abruptly. Gradually reduce the dosage when discontinuing treatment.

• Once paroxetine is discontinued, at least 14 days must elapse before initiating an MAOI.

Administration

Oral Administration

Paroxetine is commercially available in the US as paroxetine hydrochloride conventional film-coated tablets, extended-release tablets, and oral suspension and as paroxetine mesylate conventional capsules. Conventional tablets of paroxetine hydrochloride and paroxetine mesylate capsules are not bioequivalent.

Administer paroxetine hydrochloride conventional tablets, extended-release tablets, and oral suspension once daily (in the morning) without regard to meals. Administer paroxetine mesylate capsules once at bedtime with or without food.

Shake paroxetine hydrochloride oral suspension well just prior to administration.

Swallow extended-release tablets whole; do not chew or crush.

Dosage

Available as paroxetine hydrochloride and paroxetine mesylate; dosage expressed in terms of paroxetine.

When discontinuing paroxetine hydrochloride, gradually reduce dosage rather than stopping abruptly whenever possible. Adverse reactions may occur upon discontinuation of paroxetine.

Adults

Major Depressive Disorder

Oral

Paroxetine hydrochloride conventional tablets or suspension: Initially, 20 mg once daily. If no improvement, dosage may be increased in 10-mg increments at weekly intervals to a maximum of 50 mg daily.

Paroxetine hydrochloride extended-release tablets: Initially, 25 mg once daily. If no improvement, dosage may be increased in 12.5-mg increments at weekly intervals to a maximum of 62.5 mg daily.

Obsessive-Compulsive Disorder

Oral

Paroxetine hydrochloride conventional tablets or suspension: Initially, 20 mg once daily. If no improvement, dosage may be increased in 10-mg increments at weekly intervals to a maximum of 60 mg daily.

Panic Disorder

Oral

Paroxetine hydrochloride conventional tablets or suspension: Initially, 10 mg once daily. If no improvement, dosage may be increased in 10-mg increments at weekly intervals, to a maximum of 60 mg daily.

Paroxetine hydrochloride extended-release tablets: Initially, 12.5 mg once daily. If no improvement, dosage may be increased in 12.5-mg increments at weekly intervals to a maximum of 75 mg daily.

Social Anxiety Disorder

Oral

Paroxetine hydrochloride conventional tablets or suspension: 20 mg once daily; doses up to 60 mg daily have been studied but no additional clinical benefit was observed above 20 mg daily.

Paroxetine hydrochloride extended-release tablets: Initially, 12.5 mg once daily. If dosage is increased, use 12.5-mg increments at weekly intervals to a maximum of 37.5 mg daily.

Generalized Anxiety Disorders

Oral

Paroxetine hydrochloride conventional tablets or suspension: Initially, 20 mg daily; no additional clinical benefit was observed with higher dosages (above 20 mg daily).

Posttraumatic Stress Disorder

Oral

Paroxetine hydrochloride conventional tablets or suspension: Initially, 20 mg daily; if no improvement, dosage may be increased in 10-mg increments at weekly intervals, to a maximum of 50 mg daily.

Premenstrual Dysphoric Disorder

Oral

Paroxetine hydrochloride extended-release tablets: Initially, 12.5 mg once daily; may be administered daily throughout menstrual cycle or intermittently only during luteal phase (i.e., starting daily dosage 14 days prior to anticipated onset of menstruation and continuing through onset of menses). Intermittent dosing is repeated with each new cycle. If no improvement, dosage may be increased at weekly intervals to a maximum of 25 mg daily, depending on tolerability.

Vasomotor Symptoms Due to Menopause

Oral

Paroxetine mesylate capsules: 7.5 mg once daily at bedtime.

Special Populations

Hepatic Impairment

Paroxetine hydrochloride conventional tablets or suspension: In patients with severe hepatic impairment, 10 mg daily initially. Do not exceed 40 mg daily.

Paroxetine hydrochloride extended-release tablets: In patients with severe hepatic impairment, 12.5 mg daily initially. If necessary, reduce initial dose and increase intervals between upward titration of the dosage. Do not exceed 50 mg daily for major depressive disorder or panic disorder treatment. Do not exceed 37.5 mg daily for social anxiety disorder treatment.

Paroxetine mesylate capsules: No dosage adjustment necessary.

Renal Impairment

Paroxetine hydrochloride conventional tablets or suspension: In patients with severe renal impairment, 10 mg daily initially. Do not exceed 40 mg daily.

Paroxetine hydrochloride extended-release tablets: In patients with severe renal impairment, 12.5 mg daily initially. If necessary, reduce initial dose and increase intervals between upward titration of the dosage. Do not exceed 50 mg daily for major depressive disorder or panic disorder treatment. Do not exceed 37.5 mg daily for social anxiety disorder treatment.

Paroxetine mesylate capsules: No dosage adjustment necessary.

Geriatric Patients

Paroxetine hydrochloride conventional tablets or suspension: For elderly patients, 10 mg daily initially. Do not exceed 40 mg daily.

Paroxetine hydrochloride extended-release tablets: In elderly patients, 12.5 mg daily initially. Do not exceed 50 mg daily for major depressive disorder or panic disorder treatment. Do not exceed 37.5 mg daily for social anxiety disorder treatment.

Paroxetine mesylate capsules: No dosage adjustment necessary.

Pharmacogenomic Considerations

Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines provide dosing recommendations for paroxetine based on CYP2D6 phenotype. For patients identified as CYP2D6 ultrarapid metabolizers, select an alternative drug not predominantly metabolized by CYP2D6. For CYP2D6 intermediate metabolizers, consider a lower starting dose and a slower titration schedule compared to the recommended starting dose. For CYP2D6 poor metabolizers, consider a 50% reduction of the recommended starting dose, a slower titration schedule, and a 50% lower maintenance dose as compared with normal metabolizers.

Cautions for PARoxetine

Contraindications

• Concomitant use of monoamine oxidase inhibitors (MAOIs) (including linezolid and IV methylene blue) or use within 14 days of discontinuing an MAOI, due to an increased risk of serotonin syndrome.

• Concomitant use of thioridazine, due to the risk of QT prolongation.

• Concomitant use of pimozide, due to the risk of QT prolongation.

• Known hypersensitivity (e.g., anaphylaxis, angioedema, Stevens-Johnson syndrome) to paroxetine or any of the inactive ingredients of the formulation.

• Paroxetine mesylate only: Pregnancy; vasomotor symptoms do not occur during pregnancy and paroxetine can cause fetal harm.

Warnings/Precautions

Warnings

Worsening of Depression and Suicidality Risk

Increased risk of suicidal thoughts and behaviors in pediatric and young adult patients. (See Boxed Warning.) Monitor all antidepressant-treated patients for any indication of clinical worsening and emergence of suicidal thoughts and behaviors, especially during initial few months of therapy, and at times of dosage changes. Counsel family members or caregivers to monitor for changes and to alert the clinician. Consider changing the therapeutic regimen, including discontinuation of paroxetine, in patients whose depression is persistently worse, or who are experiencing emergent suicidal thoughts or behaviors.

Other Warnings/Precautions

Serotonin Syndrome

Can precipitate serotonin syndrome, a potentially life-threatening condition. Risk increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, meperidine, methadone, tryptophan, buspirone, amphetamines and St. John’s Wort) and with drugs that impair metabolism of serotonin (i.e., MAOIs). Serotonin syndrome can also occur when these drugs are used alone.

Symptoms may include mental status changes (e.g., agitation, hallucinations, delirium, and coma), autonomic instability (e.g., tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular symptoms (e.g., tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures, and/or GI symptoms (e.g., nausea, vomiting, diarrhea).

Concomitant use of paroxetine with MAOIs is contraindicated. Do not initiate paroxetine in a patient being treated with MAOIs such as linezolid or IV methylene blue. If necessary to initiate treatment with an MAOI such as linezolid or IV methylene blue, discontinue paroxetine before initiating MAOI.

Monitor all patients for emergence of serotonin syndrome. Discontinue treatment with paroxetine and any concomitant serotonergic agents immediately if symptoms occur, and initiate supportive symptomatic treatment. If concomitant use with other serotonergic drugs clinically warranted, inform patients of increased risk for serotonin syndrome and monitor for symptoms.

Drug Interactions Leading to QT Prolongation

CYP2D6 inhibitory properties of paroxetine can elevate plasma levels of thioridazine and pimozide. Since thioridazine and pimozide given alone produce prolongation of the QTc interval and increase the risk of serious ventricular arrhythmias, use of paroxetine is contraindicated in combination with thioridazine or pimozide.

Fetal/Neonatal Morbidity and Mortality

Exposure to paroxetine in first trimester of pregnancy is associated with a less than 2-fold increase in the rate of cardiovascular malformations among infants.

For women who intend to become pregnant or who are in their first trimester of pregnancy, initiate paroxetine only after consideration of other available treatment options.

Increased Risk of Bleeding

Increased risk of bleeding events including ecchymoses, hematomas, epistaxis, petechiae, GI bleeding, postpartum hemorrhage, and life-threatening bleeding. Concomitant use of aspirin, NSAIAs, other antiplatelet drugs, warfarin, and other anticoagulants may add to this risk.

Inform patients about increased risk of bleeding associated with the concomitant use of paroxetine and antiplatelet agents or anticoagulants. For patients taking warfarin, carefully monitor INR.

Activation of Mania or Hypomania

In patients with bipolar disorder, treating a depressive episode with paroxetine or another antidepressant may precipitate a mixed/manic episode.

Prior to initiating treatment, screen patients for any personal or family history of bipolar disorder, mania, or hypomania.

Discontinuation Syndrome

Adverse reactions after discontinuation of serotonergic antidepressants, particularly after abrupt discontinuation, include nausea, sweating, dysphoric mood, irritability, agitation, dizziness, sensory disturbances (e.g., paresthesia, such as electric shock sensations), tremor, anxiety, confusion, headache, lethargy, emotional lability, insomnia, hypomania, tinnitus, and seizures.

Reduce paroxetine dosage gradually rather than discontinuing abruptly.

Seizures

Patients with a history of seizures were excluded from clinical studies of paroxetine.

Use with caution in patients with a seizure disorder; discontinue drug in any patient who develops seizures.

Angle-Closure Glaucoma

Cases of angle-closure glaucoma reported.

Avoid use in patients with untreated anatomically narrow angles.

Hyponatremia

Hyponatremia, most likely due to syndrome of inappropriate antidiuretic hormone secretion (SIADH), may occur. Signs and symptoms of hyponatremia include headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness, which may lead to falls. Signs and symptoms associated with more severe and/or acute cases have included hallucination, syncope, seizure, coma, respiratory arrest, and death. Elderly patients, patients taking diuretics, and those who are volume-depleted may be at greater risk.

In patients with symptomatic hyponatremia, discontinue paroxetine and institute appropriate medical intervention.

Reduction of Efficacy of Tamoxifen

Efficacy of tamoxifen may be reduced with concomitant use of paroxetine.

When tamoxifen is used for prevention or treatment of breast cancer, consider using an antidepressant with little to no CYP2D6 inhibition.

Bone Fracture

Association between antidepressant (including SSRI) treatment and bone fractures reported in epidemiological studies.

Sexual Dysfunction

May cause symptoms of sexual dysfunction. In male patients, may result in ejaculatory delay or failure, decreased libido, and erectile dysfunction. In female patients, may result in decreased libido and delayed or absent orgasm.

Inquire about sexual function prior to initiation and inquire specifically about changes in sexual function during treatment. Obtain a detailed history (including timing of symptom onset) when evaluating changes in sexual function to rule out other causes, including the underlying psychiatric disorder. Discuss potential management strategies to support patients in making informed decisions about treatment.

Specific Populations

Pregnancy

Paroxetine mesylate capsules are contraindicated for use in pregnant women because menopausal vasomotor symptoms do not occur during pregnancy and paroxetine can cause fetal harm.

Advise patients to register in the National Pregnancy Registry for Antidepressants by calling 1-866- 961-2388 or visiting online at [Web].

Associated with a less than 2-fold increase in cardiovascular malformations when administered to pregnant women during the first trimester. Risk of persistent pulmonary hypertension of the newborn (PPHN) and/or poor neonatal adaptation with exposure during pregnancy. Use in the month before delivery may be associated with an increased risk of postpartum hemorrhage. There are also risks associated with untreated depression in pregnancy.

Consider risk of untreated depression when discontinuing or changing treatment with antidepressants during pregnancy and postpartum.

For women who intend to become pregnant or who are in their first trimester of pregnancy, initiate paroxetine only after consideration of the other available treatment options.

Lactation

Distributed into human milk. Monitor for adverse symptoms of agitation, irritability, poor feeding, and poor weight gain in exposed infants.

Consider developmental and health benefits of breast-feeding along with mother’s clinical need for paroxetine and any potential adverse effects on the breast-fed child from paroxetine or from the underlying maternal condition.

Pediatric Use

Safety and efficacy of paroxetine hydrochloride not established in children <18 years of age. Main safety concern is the increased risk of suicidal thoughts and behaviors.

Paroxetine mesylate capsules not indicated for use in pediatric population.

Geriatric Use

Pharmacokinetic studies revealed decreased clearance in the elderly; lower starting dose of paroxetine hydrochloride recommended. No overall differences in safety or effectiveness observed between elderly and younger patients.

Clinically significant hyponatremia may occur in elderly patients, who may be at greater risk for this adverse reaction.

Clinical studies of paroxetine mesylate capsules did not include sufficient numbers of patients ≥65 years of age to determine whether they respond differently from younger subjects. Elderly patients may have elevated paroxetine plasma concentrations compared to younger patients. However, no dosage adjustment of paroxetine mesylate capsules necessary.

Hepatic Impairment

Increased plasma concentrations reported; reduce initial dosage of paroxetine hydrochloride if impairment is severe.

No dosage adjustment of paroxetine mesylate capsules required.

Renal Impairment

Increased plasma concentrations reported; reduce initial dosage of paroxetine hydrochloride if impairment is severe.

No dosage adjustment of paroxetine mesylate capsules required.

Common Adverse Effects

Most common adverse effects with paroxetine hydrochloride conventional tablets and suspension (≥5% and at least twice placebo) are abnormal ejaculation, asthenia, constipation, decreased appetite, diarrhea, dizziness, dry mouth, female genital disorder, impotence, infection, insomnia, libido decreased, male genital disorder, nausea, nervousness, somnolence, sweating, tremor, yawn.

Most common adverse effects with paroxetine hydrochloride extended-release tablets (≥5% and at least twice placebo) are abnormal ejaculation, abnormal vision, asthenia, constipation, decreased appetite, diarrhea, dizziness, dry mouth, female genital disorder, impotence, insomnia, libido decreased, nausea, somnolence, sweating, tremor.

Most common adverse effects with paroxetine mesylate capsules (≥2% and at a higher incidence that placebo) are headache, fatigue, malaise, lethargy, nausea, vomiting.

Drug Interactions

Metabolized partially by CYP2D6. Strong inhibitor of the activity of CYP2D6 and to a lesser extent CYP3A4.

Drugs Undergoing Hepatic Metabolism or Affecting Hepatic Microsomal Enzymes

Drugs Metabolized by CYP2D6: Possible increased plasma concentrations of the CYP2D6 substrates. Examples of drugs that are CYPD2D6 substrates include propafenone, flecainide, atomoxetine, desipramine, dextromethorphan, metoprolol, nebivolol, perphenazine, tolterodine, venlafaxine, and risperidone. Reduce dosage of concomitantly administered CYP2D6 substrate. Increase in dosage of CYP2D6 substrate may be needed with paroxetine discontinuation.

Drugs Metabolized by CYP3A4: Extent of paroxetine’s inhibition of CYP3A4 activity unlikely to be of clinical importance based on in vivo and in vitro studies.

Serotonergic Drugs

Potentially life-threatening serotonin syndrome with other serotonergic drugs. Examples of serotonergic drugs include other SSRIs, SNRIs, triptans, tricyclic antidepressants, opioids, lithium, tryptophan, buspirone, amphetamines, and St. John’s Wort.

Monitor patients for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increases. If serotonin syndrome occurs, consider discontinuing paroxetine and/or any concurrently administered serotonergic agents.

Drugs Highly Bound to Plasma Protein

Potential displacement of or by other highly-protein bound drugs (e.g., warfarin). Paroxetine does not alter in vitro protein binding of phenytoin or warfarin.

Monitor for adverse reactions and reduce dosage of paroxetine or other protein-bound drugs as warranted.

Drugs that Interfere with Hemostasis

Potential pharmacologic interaction (increased risk of bleeding) with concomitant use of drugs that affect hemostasis such as aspirin, clopidogrel, heparin, or warfarin.

Inform patients of increased risk of bleeding associated with concomitant use of paroxetine and antiplatelet and anticoagulant agents. For patients taking warfarin, closely monitor INR.

Monoamine Oxidase Inhibitors

Concomitant use of paroxetine with MAO inhibitors, including selegiline, tranylcypromine, isocarboxazid, phenelzine, linezolid, and methylene blue, is contraindicated due to the risk of serotonin syndrome.

At least 14 days must elapse between discontinuation of an MAOI and initiation of paroxetine; additionally, at least 14 days must elapse after stopping paroxetine before starting an MAOI.

Specific Drugs

PARoxetine Pharmacokinetics

Absorption

Bioavailability

Completely absorbed following oral administration. ; absorption rate is reduced and slightly delayed with extended-release tablet.

Equally bioavailable from commercially available paroxetine hydrochloride conventional tablets and suspension.

Conventional tablets of paroxetine hydrochloride (Paxil) and paroxetine mesylate capsules are not bioequivalent.

Food

Administration of single dose of paroxetine hydrochloride with food resulted in a 6 and 29% increase in AUC and peak plasma concentration, respectively; time to peak plasma concentrations decreased from 6.4 to 4.9 hours.

Distribution

Extent

Widely distributed in the body, including CNS and breast milk.

Plasma Protein Binding

Approximately 95 and 93% bound to plasma proteins at plasma concentrations of 100 and 400 ng/mL, respectively.

Elimination

Metabolism

Extensively metabolized, partially by CYP2D6. Metabolites are essentially inactive.

Inhibits activity of CYP2D6.

Elimination Route

Eliminated principally in urine and feces (probably via bile).

Half-life

21 hours (administered as paroxetine hydrochloride immediate-release formulation); between 15—20 hours (administered as paroxetine hydrochloride extended-release formulation).

Special Populations

In patients with renal impairment (Cl_cr <30 mL/minute), mean plasma paroxetine concentrations are approximately 4 times greater than those seen in healthy individuals.

Hepatic impairment may increase plasma concentrations twofold.

Stability

Storage

Oral

Paroxetine Hydrocholoride Conventional Tablets

15–30°C.

Paroxetine Hydrochloride Extended-release Tablets

≤25°C; excursion permitted from 15–30°C..

Paroxetine Hydrochloride Suspension

≤25°C.

Paroxetine Mesylate Conventional Capsules

≤25°C. Protect capsules from light and humidity.

Actions

• Potent and highly selective reuptake inhibitor of serotonin.

• Mechanism of action as an antidepressant presumed to be linked to potentiation of serotonergic activity in the CNS resulting from inhibition of CNS neuronal reuptake of serotonin (5-HT).

• Precise mechanism of action in obsessive-compulsive disorder, panic disorder, social phobia, or generalized anxiety disorder not fully elucidated but appears to involve inhibition of serotonin reuptake.

• Has little or no effect on other neurotransmitters or any clinically important anticholinergic, antihistaminic, or adrenergic (α₁, α₂, β) blocking activity at usual therapeutic dosages.

Advice to Patients

• Advise patients to read the FDA-approved patient labeling (Medication Guide).

• Advise patients and caregivers to look for the emergence of suicidality, especially early during treatment and when the dosage is adjusted up or down and instruct them to report such symptoms to their clinician.

• Caution patients about the risk of serotonin syndrome, particularly with the concomitant use of paroxetine with other serotonergic drugs, including triptans, tricyclic antidepressants, opioids, lithium, tryptophan, buspirone, amphetamines, St. John’s Wort, and with drugs that impair metabolism of serotonin (in particular, monoamine oxidase inhibitors, both those intended to treat psychiatric disorders and others, such as linezolid). Instruct patients to contact their clinician or report to the emergency room if they experience signs or symptoms of serotonin syndrome.

• Advise patients to inform their clinician if they are taking, or plan to take, any prescription or OTC drugs, since there is a potential for drug-drug interactions.

• Inform patients about the possible increased risk of bleeding associated with concomitant use of paroxetine and aspirin, nonsteroidal anti-inflammatory agents, other antiplatelet drugs, warfarin, or other anticoagulants. Advise patients to inform their clinician if they are taking or planning to take any prescription or OTC medications that increase the risk of bleeding.

• Advise patients and their caregivers to observe for signs of activation of mania/hypomania and instruct them to report such symptoms to the clinician.

• Advise patients not to abruptly discontinue paroxetine and to discuss any tapering regimen with their clinician. Inform patients that adverse reactions can occur when paroxetine is discontinued.

• Advise patients that use of paroxetine may cause symptoms of sexual dysfunction in both male and female patients. Inform patients that they should discuss any changes in sexual function and potential management strategies with their clinician.

• Instruct patients to shake the oral suspension well before administration.

• Advise patients to notify their clinician if they develop an allergic reaction such as rash, hives, swelling, or difficulty breathing.

• Advise women to notify their clinician if they become pregnant or intend to become pregnant during treatment with paroxetine. Advise women of risks associated with first trimester use of paroxetine and that use later in pregnancy may lead to an increased risk for neonatal complications requiring prolonged hospitalization, respiratory support, tube feeding, and/or persistent pulmonary hypertension of the newborn (PPHN).

• Advise women that there is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to paroxetine during pregnancy.

• Advise breast-feeding women using paroxetine to monitor infants for agitation, irritability, poor feeding, and poor weight gain and to seek medical care if they notice these signs.

• Advise men that paroxetine may affect sperm quality, which may impair fertility; it is not known if this effect is reversible.

• Advise patients that taking paroxetine capsules can cause mild pupillary dilation, which in susceptible individuals, can lead to an episode of angle-closure glaucoma. Patients may wish to be examined to determine whether they are susceptible to angle closure, and have a prophylactic procedure (e.g., iridectomy), if they are susceptible.

• Advise patients about the risk of hyponatremia, particularly elderly patients and those who are taking diuretics or are volume-depleted.

• Inform patients that there is the possibility for an increased risk of fracture.

• Inform patients of other important precautionary information.

Additional Information

The American Society of Health-System Pharmacists, Inc. represents that the information provided in the accompanying monograph was formulated with a reasonable standard of care, and in conformity with professional standards in the field. Readers are advised that decisions regarding use of drugs are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and that the information contained in the monograph is provided for informational purposes only. The manufacturer’s labeling should be consulted for more detailed information. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information contained in the monograph is not a substitute for medical care.

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

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