Citalopram

12.1 Mechanism of Action The mechanism of action of citalopram is unclear, but is presumed to be related to potentiation of serotonergic activity in the central nervous system (CNS) resulting from its inhibition of CNS neuronal reuptake of serotonin (5-HT).

1 INDICATIONS AND USAGE Citalopram tablets are indicated for the treatment of major depressive disorder (MDD) in adults [see Clinical Studies (14) ] . Citalopram tablets are a selective serotonin reuptake inhibitor (SSRI) indicated for the treatment of major depressive disorder (MDD) in adults ( 1 ) .

2 DOSAGE AND ADMINISTRATION Administer once daily with or without food ( 2 ) . Initial dosage is 20 mg once daily; after one week may increase to maximum dosage of 40 mg once daily ( 2.1 ). Patients greater than 60 years of age, patients with hepatic impairment, and CYP2C19 poor metabolizers: maximum recommended dosage is 20 mg once daily ( 2.2 ). When discontinuing citalopram tablets, reduce dosage gradually ( 2.4 , 5.6 ). 2.1 Recommended Dosage Administer citalopram tablets once daily, with or without food, at an initial dosage of 20 mg once daily, with an increase to a maximum dosage of 40 mg once daily at an interval of no less than one week. Dosages above 40 mg once daily are not recommended due to the risk of QT prolongation [see Warnings and Precautions (5.2) ] . 2.2 Screen for Bipolar Disorder Prior to Starting Citalopram Tablets Prior to initiating treatment with citalopram tablets or another antidepressant, screen patients for a personal or family history of bipolar disorder, mania, or hypomania [See Warnings and Precautions (5.5) ]. 2.3 Recommended Dosage for Specific Populations The maximum recommended dosage of citalopram tablets for patients who are greater than 60 years of age, patients with hepatic impairment, and for CYP2C19 poor metabolizers is 20 mg once daily [see Warnings and Precautions (5.2) , Clinical Pharmacology (12.3) ]. 2.4 Dosage Modifications with Concomitant Use of CYP2C19 Inhibitors The maximum recommended dosage of citalopram tablets when used concomitantly with a CYP2C19 inhibitor is 20 mg once daily [see Warnings and Precautions (5.2) , Drug Interactions (7) ]. 2.5 Switching Patients to or from a Monoamine Oxidase Inhibitor Antidepressant At least 14 days must elapse between discontinuation of a monoamine oxidase inhibitor (MAOI) antidepressant and initiation of therapy with citalopram tablets. Conversely, at least 14 days must elapse after stopping citalopram tablets before starting an MAOI antidepressant [see Contraindications (4) and Warnings and Precautions (5.3) ] . 2.6 Discontinuing Treatment with Citalopram Tablets Adverse reactions may occur upon discontinuation of citalopram tablets [see Warnings and Precautions (5.6) ] . Gradually reduce the dosage rather than stopping citalopram tablets abruptly whenever possible.

6 ADVERSE REACTIONS The following adverse reactions are discussed in greater detail in other sections of the labeling: Hypersensitivity reactions [see Contraindications (4) ] Suicidal thoughts and behaviors in adolescents and young adults [see Warnings and Precautions (5.1) ] QT-prolongation and torsade de pointes [see Warnings and Precautions (5.2) ] Serotonin syndrome [see Warnings and Precautions (5.3) ] Increased risk of bleeding [see Warnings and Precautions (5.4) ] Activation of mania or hypomania [see Warnings and Precautions (5.5) ] Discontinuation syndrome [see Warnings and Precautions (5.6) ] Seizures [see Warnings and Precautions (5.7) ] Angle-closure glaucoma [see Warnings and Precautions (5.8) ] Hyponatremia [see Warnings and Precautions (5.9) ] Sexual Dysfunction [see Warnings and Precautions (5.10) ] Most common adverse reaction (incidence ≥ 5% and twice placebo) is ejaculation disorder (primarily ejaculation delay) ( 6.1 ) . To report SUSPECTED ADVERSE REACTIONS, contact Aurobindo Pharma USA, Inc. at 1-866-850-2876 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in clinical practice. The safety for citalopram included citalopram exposures in patients and/or healthy subjects from 3 different groups of studies: 429 healthy subjects in clinical pharmacology/pharmacokinetic studies; 4,422 exposures from patients in controlled and uncontrolled clinical trials, corresponding to approximately 1,370 patient-exposure years. There were, in addition, over 19,000 exposures from mostly open-label, European postmarketing studies. The conditions and duration of treatment with citalopram varied greatly and included (in overlapping categories) open-label and double-blind studies, inpatient and outpatient studies, fixed-dose and dose-titration studies, and short-term and long-term exposure. Adverse Reactions Associated with Discontinuation of Treatment Among 1,063 patients with MDD who received citalopram at doses ranging from 10 mg to 80 mg once daily in placebocontrolled trials of up to 6 weeks duration, 16% discontinued treatment due to an adverse reaction, as compared to 8% of 446 patients receiving placebo. The adverse reactions associated with discontinuation (i.e., associated with discontinuation in at least 1% of citalopram-treated patients at a rate at least twice that of placebo) are shown in Table 2 . Table 2: Adverse Reactions Associated with Discontinuation of Citalopram Treatment in Short-Term, Placebo-Controlled MDD Trials * A patient can report more than one reason for discontinuation and be counted more than once in this table. Body System/Adverse Reaction Citalopram Placebo (N=1,063) % (N=446) % General Asthenia 1 <1 Gastrointestinal Disorders Nausea 4 0 Dry Mouth 1 <1 Vomiting 1 0 Central and Peripheral Nervous System Disorders Dizziness 2 <1 Psychiatric Disorders Insomnia 3 1 Somnolence 2 1 Agitation 1 <1 Table 3 enumerates the incidence of adverse reactions that occurred among 1,063 patients with MDD who received citalopram at doses ranging from 10 mg to 80 mg once daily in placebo-controlled trials of up to 6 weeks duration. The most common adverse reaction that occurred in citalopram-treated patients with an incidence of 5% or greater and at least twice the incidence in placebo patients was ejaculation disorder (primarily ejaculatory delay) in male patients (see Table 3 ). Table 3: Adverse Reactions (≥2% and Greater than Placebo) Among Citalopram-Treated Patients * *Adverse reactions reported by at least 2% of patients treated with citalopram are reported, except for the following adverse reactions which had an incidence on placebo ≥ citalopram: headache, asthenia, dizziness, constipation, palpitation, vision abnormal, sleep disorder, nervousness, pharyngitis, micturition disorder, back pain. 1 Denominator used was for females only (N=638 citalopram; N=252 placebo). 2 Primarily ejaculatory delay. 3 Denominator used was for males only (N=425 citalopram; N=194 placebo). Body System/Adverse Reaction Citalopram Placebo (N=1,063) % (N=446) % Gastrointestinal Disorders Nausea 21 14 Diarrhea 8 5 Dyspepsia 5 4 Vomiting 4 3 Abdominal Pain 3 2 Autonomic Nervous System Disorders Dry Mouth 20 14 Sweating Increased 11 9 Psychiatric Disorders Somnolence 18 10 Insomnia 15 14 Anxiety 4 3 Anorexia 4 2 Agitation 3 1 Dysmenorrhea 1 3 2 Libido Decreased 2 <1 Yawning 2 <1 Central & Peripheral Nervous System Disorders Tremor 8 6 Urogenital Ejaculation Disorder 2,3 6 1 Impotence 3 3 <1 Respiratory System Disorders Upper Respiratory Tract Infection 5 4 Rhinitis 5 3 Sinusitis 3 <1 General Fatigue 5 3 Fever 2 <1 Musculoskeletal System Disorders Arthralgia 2 1 Myalgia 2 1 Dose Dependent Adverse Reactions The potential relationship be

7 DRUG INTERACTIONS Table 5 presents clinically important drug interactions with citalopram. Table 5: Clinically Important Drug Interactions with Citalopram Monoamine Oxidase Inhibitors (MAOIs) Clinical Impact Concomitant use of SSRIs, including citalopram, and MAOIs increases the risk of serotonin syndrome. Intervention Citalopram 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 (5.3) ] . Pimozide Clinical Impact: Concomitant use of citalopram with pimozide increases plasma concentrations of pimozide, a drug with a narrow therapeutic index, and may increase the risk of QT prolongation and/or ventricular arrhythmias compared to use of citalopram alone [see Clinical Pharmacology (12.2) ]. Intervention: Citalopram is contraindicated in patients taking pimozide [see Contraindications (4) , Warnings and Precautions (5.2) ]. Drugs that Prolong the QTc Interval Clinical Impact: Concomitant use of citalopram with drugs that prolong QT can cause additional QT prolongation compared to the use of citalopram alone [see Clinical Pharmacology (12.2) ]. Intervention: Avoid concomitant use of citalopram with drugs that prolong the QT interval (citalopram is contraindicated in patients taking pimozide) [see Contraindications (4) , Warnings and Precautions (5.2) ]. CYP2C19 Inhibitors Clinical Impact: Concomitant use of citalopram with CYP2C19 inhibitors increases the risk of QT prolongation and/or ventricular arrhythmias compared to the use of citalopram alone [see Clinical Pharmacology (12.2) ]. Intervention: The maximum recommended dosage of citalopram is 20 mg daily when used concomitantly with a CYP2C19 inhibitor [see Dosage and Administration (2.4) , Warnings and Precautions (5.2) ]. Other Serotonergic Drugs Clinical Impact: Concomitant use of citalopram and other serotonergic drugs (including other SSRIs, SNRIs, triptans, tricyclic antidepressants, opioids, lithium, buspirone, amphetamines, tryptophan, and St. John's Wort) increases the risk of serotonin syndrome. Intervention: Monitor patients for signs and symptoms of serotonin syndrome, particularly during citalopram initiation and dosage increases. If serotonin syndrome occurs, consider discontinuation of citalopram and/or concomitant serotonergic drugs [see Warning and Precautions (5.3) ]. Drugs That Interfere With Hemostasis (antiplatelet agents and anticoagulants) Clinical Impact: Concomitant use of citalopram and an antiplatelet or anticoagulant may potentiate the risk of bleeding. Intervention: Inform patients of the increased risk of bleeding associated with the concomitant use of citalopram and antiplatelet agents and anticoagulants. For patients taking warfarin, carefully monitor the international normalized ratio [see Warning and Precautions (5.4) ]. CYP2C19 Inhibitors : Citalopram 20 mg daily is the maximum recommended dosage for patients taking concomitant CYP2C19 inhibitors ( 5.2 , 7 ) .