Paroxetine

Brand Names: Paroxetine

Drug Class: General Prescription

Overview

11 DESCRIPTION Paroxetine tablets, USP contains paroxetine hydrochloride, an SSRI. It is the hydrochloride salt of a phenylpiperidine compound identified chemically as (-)- trans -4 R -(4'-fluorophenyl)-3 S -[(3',4'- methylenedioxyphenoxy) methyl] piperidine hydrochloride hemihydrate and has the molecular formula of C 19 H 20 FNO 3 •HCl•1/2H 2 O. The molecular weight is 374.8 (329.4 as free base).

Mechanism of Action

12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action The mechanism of action of paroxetine in the treatment of MDD, SAD, OCD, PD, GAD, and PTSD is unknown, but is presumed to be linked to potentiation of serotonergic activity in the central nervous system resulting from inhibition of neuronal reuptake of serotonin (5-hydroxy-tryptamine, 5-HT). 12.2 Pharmacodynamics Studies at clinically relevant doses in humans have demonstrated that paroxetine blocks the uptake of serotonin into human platelets. In vitro studies in animals also suggest that paroxetine is a potent and highly selective inhibitor of neuronal serotonin reuptake (SSRI) and has only very weak effects on norepinephrine and dopamine neuronal reuptake. 12.

Indications

  • 1 INDICATIONS AND USAGE Paroxetine tablets are indicated in adults for the treatment of: Major depressive disorder (MDD) Obsessive compulsive disorder (OCD) Panic disorder (PD) Social anxiety disorder (SAD) Generalized anxiety disorder (GAD) Posttraumatic stress disorder (PTSD) Paroxetine is a selective serotonin reuptake inhibitor (SSRI) indicated in adults for the treatment of ( 1 ): Major Depressive Disorder (MDD) Obsessive Compulsive Disorder (OCD) Panic Disorder (PD) Social Anxiety Disorder (SAD) Generalized Anxiety Disorder (GAD) Posttraumatic Stress Disorder (PTSD)

Common Doses

  • 20 mg
  • 50 mg
  • 60 mg
  • 10 mg

Dosage

2 DOSAGE AND ADMINISTRATION Recommended starting and maximum daily dosage for MDD, OCD, PD, and PTSD: ( 2.2 ) Indication Starting Daily Dose Maximum Daily Dose MDD 20 mg 50 mg OCD 20 mg 60 mg PD 10 mg 60 mg PTSD 20 mg 50 mg Recommended starting dosage for SAD and GAD is 20 mg daily. ( 2.3 ) Elderly patients, patients with severe renal impairment or severe hepatic impairment: Starting dosage is 10 mg daily. Maximum dosage is 40 mg daily. ( 2.4 ) When discontinuing paroxetine tablets, reduce dosage gradually. ( 2.6 , 5.7 ) 2.

Black Box Warning

BOXED WARNING WARNING: SUICIDAL THOUGHTS AND BEHAVIORS Antidepressants increased the risk of suicidal thoughts and behaviors in pediatric and young adult patients in short-term studies. Closely monitor all antidepressant-treated patients for clinical worsening, and for emergence of suicidal thoughts and behaviors [see Warnings and Precautions ( 5.1 )]. Paroxetine is not approved for use in pediatric patients [see Use in Specific Populations ( 8.4 )]. WARNING: SUICIDAL THOUGHTS AND BEHAVIORS See full prescribing information for complete boxed warning.

Contraindications

  • 4 CONTRAINDICATIONS Paroxetine tablets are contraindicated in patients: Taking, or within 14 days of stopping, MAOIs (including the MAOIs linezolid and intravenous methylene blue) because of an increased risk of serotonin syndrome [see Warnings and Precautions ( 5.2 ), Drug Interactions ( 7) ]. Taking thioridazine because of risk of QT prolongation [see Warnings and Precautions ( 5.3 , Drug Interactions ( 7 )] Taking pimozide because of risk of QT prolongation [see Warnings and Precautions ( 5.3 ), Drug Interactions ( 7 )]. With known hypersensitivity (e.g.

Side Effects

  • 6 ADVERSE REACTIONS The following adverse reactions are included in more detail in other sections of the prescribing information: Hypersensitivity reactions to paroxetine [see Contraindications ( 4 )] Suicidal Thoughts and Behaviors [see Warnings and Precautions ( 5.1 )] Serotonin Syndrome [see Warnings and Precautions ( 5.2 )] Embryofetal Toxicity [see Warnings and Precautions ( 5.4 )] Increased Risk of Bleeding [see Warnings and Precautions ( 5.5 )] Activation of Mania/Hypomania [see Warnings and Precautions ( 5.6 )] Discontinuation Syndrome [see Warnings and Precautions ( 5.

Interactions

  • 7 DRUG INTERACTIONS Table 9 presents clinically significant drug interactions with paroxetine. Table 9 Clinically Significant Drug Interactions with Paroxetine Monoamine Oxidase Inhibitors (MAOIs) Clinical Impact The concomitant use of SSRIs, including paroxetine, and MAOIs increases the risk of serotonin syndrome. Intervention Paroxetine is contraindicated in patients taking MAOIs, including MAOIs such as linezolid or intravenous methylene blue [see Dosage and Administration ( 2.5 ), Contraindications ( 4 ), Warnings and Precautions ( 5.2 )] .