Mirtazapine

Recent Major Changes Contraindications ( 4 ) 11/2021 Warnings and Precautions ( 5.6 ) 11/2021

INDICATIONS AND USAGE Mirtazapine tablets, USP are indicated for the treatment of major depressive disorder. The efficacy of mirtazapine tablets, USP in the treatment of major depressive disorder was established in six week controlled trials of outpatients whose diagnoses corresponded most closely to the Diagnostic and Statistical Manual of Mental Disorders – 3rd edition (DSM-III) category of major depressive disorder (see CLINICAL PHARMACOLOGY ). A major depressive episode (DSM-IV) implies a prominent and relatively persistent (nearly every day for at least 2 weeks) depressed or dysphoric mood that usually interferes with daily functioning, and includes at least five of the following nine symptoms: depressed mood, loss of interest in usual activities, significant change in weight and/or appetite, insomnia or hypersomnia, psychomotor agitation or retardation, increased fatigue, feelings of guilt or worthlessness, slowed thinking or impaired concentration, a suicide attempt or suicidal ideation. The effectiveness of mirtazapine tablets, USP in hospitalized depressed patients has not been adequately studied. The efficacy of mirtazapine tablets, USP in maintaining a response in patients with major depressive disorder for up to 40 weeks following 8 to 12 weeks of initial open-label treatment was demonstrated in a placebo-controlled trial. Nevertheless, the physician who elects to use mirtazapine tablets, USP for extended periods should periodically re-evaluate the long-term usefulness of the drug for the individual patient (see CLINICAL PHARMACOLOGY ).

DOSAGE AND ADMINISTRATION Initial Treatment The recommended starting dose for mirtazapine tablets is 15 mg/day, administered in a single dose, preferably in the evening prior to sleep. In the controlled clinical trials establishing the efficacy of mirtazapine in the treatment of major depressive disorder, the effective dose range was generally 15 to 45 mg/day. While the relationship between dose and satisfactory response in the treatment of major depressive disorder for mirtazapine tablets has not been adequately explored, patients not responding to the initial 15 mg dose may benefit from dose increases up to a maximum of 45 mg/day. Mirtazapine tablets has an elimination half-life of approximately 20 to 40 hours; therefore, dose changes should not be made at intervals of less than one to two weeks in order to allow sufficient time for evaluation of the therapeutic response to a given dose. Elderly and Patients with Renal or Hepatic Impairment The clearance of mirtazapine is reduced in elderly patients and in patients with moderate to severe renal or hepatic impairment. Consequently, the prescriber should be aware that plasma mirtazapine levels may be increased in these patient groups, compared to levels observed in younger adults without renal or hepatic impairment (see PRECAUTIONS and CLINICAL PHARMACOLOGY ). Maintenance/Extended Treatment It is generally agreed that acute episodes of depression require several months or longer of sustained pharmacological therapy beyond response to the acute episode. Systematic evaluation of mirtazapine tablets has demonstrated that its efficacy in major depressive disorder is maintained for periods of up to 40 weeks following 8 to 12 weeks of initial treatment at a dose of 15 to 45 mg/day (see CLINICAL PHARMACOLOGY ). Based on these limited data, it is unknown whether or not the dose of mirtazapine tablets needed for maintenance treatment is identical to the dose needed to achieve an initial response. Patients should be periodically reassessed to determine the need for maintenance treatment and the appropriate dose for such treatment. Switching a Patient To or From a Monoamine Oxidase Inhibitor (MAOI) Intended to Treat Psychiatric Disorders At least 14 days should elapse between discontinuation of an MAOI intended to treat psychiatric disorders and initiation of therapy with mirtazapine tablets. Conversely, at least 14 days should be allowed after stopping mirtazapine tablets before starting an MAOI intended to treat psychiatric disorders (see CONTRAINDICATIONS ). Use of Mirtazapine Tablets With Other MAOIs, Such as Linezolid or Methylene Blue Do not start mirtazapine tablets in a patient who is being treated with linezolid or intravenous methylene blue because there is an increased risk of serotonin syndrome. In a patient who requires more urgent treatment of a psychiatric condition, other interventions, including hospitalization, should be considered (see CONTRAINDICATIONS ). In some cases, a patient already receiving therapy with mirtazapine may require urgent treatment with linezolid or intravenous methylene blue. If acceptable alternatives to linezolid or intravenous methylene blue treatment are not available and the potential benefits of linezolid or intravenous methylene blue treatment are judged to outweigh the risks of serotonin syndrome in a particular patient, Mirtazapine tablets should be stopped promptly, and linezolid or intravenous methylene blue can be administered. The patient should be monitored for symptoms of serotonin syndrome for 2 weeks or until 24 hours after the last dose of linezolid or intravenous methylene blue, whichever comes first. Therapy with mirtazapine tablets may be resumed 24 hours after the last dose of linezolid or intravenous methylene blue (see WARNINGS ). The risk of administering methylene blue by non-intravenous routes (such as oral tablets or by local injection) or in intravenous doses much lower than 1 mg/kg with mirtazapine tablets is unclear. …

3 DOSAGE FORMS & STRENGTHS Mirtazapine Tablets, USP are supplied as: 7.5 mg tablets: Yellow colored, round, biconvex film-coated tablets debossed with “886” on one side and “N” on the other side, free from physical defects 15 mg tablets: Yellow colored, oblong, biconvex film-coated tablets, functionally scored on one side and debossed with “N 887” on the other side, free from physical defects 30 mg tablets: Brown colored, oblong, biconvex film-coated tablets, functionally scored on one side and debossed with “N 888” on the other side, free from physical defects 45 mg tablets: White to off white colored, oblong, biconvex film-coated tablets debossed with “N 889” on one side and plain on the other side, free from physical defects Tablets : 7.5 mg unscored, 15 mg functionally scored, 30 mg functionally scored and 45 mg unscored. (3)

4 CONTRAINDICATIONS Mirtazapine 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 ( 5.3 ), Drug Interactions ( 7 )] . • With a known hypersensitivity to mirtazapine or to any of the excipients in mirtazapine tablets . Severe skin reactions, including drug reaction with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome, bullous dermatitis, erythema multiforme and toxic epidermal necrolysis have been reported following the use of mirtazapine tablets [see Warnings and Precautions (5.6) , Adverse Reactions ( 6.2 )]. • Concomitant use of monoamine oxidase inhibitors (MAOIs) or use within 14 days of stopping MAOIs. ( 2.4 , 4 , 7 ) • Known hypersensitivity to mirtazapine or any of the excipients in mirtazapine tablets. ( 4 )

6 ADVERSE REACTIONS The following adverse reactions are described in more detail in other sections of the prescribing information: Hypersensitivity [see Contraindications (4) ] Suicidal Thoughts and Behaviors [see Warnings and Precautions (5.1) ] Agranulocytosis [see Warnings and Precautions (5.2) ] Serotonin Syndrome [see Contraindications (4) , Warnings and Precautions (5.3) , Drug Interactions (7) ] Angle-Closure Glaucoma [see Warnings and Precautions (5.4) ] QT Prolongation and Torsades de Pointes [see Warnings and Precautions (5.5) ] Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) [see Warnings and Precautions (5.6) ] Increased Appetite and Weight Gain [see Warnings and Precautions (5.7) ] Somnolence [see Warnings and Precautions (5.8) ] Activation of Mania or Hypomania [see Warnings and Precautions (5.9) ] Seizures [see Warnings and Precautions (5.10) ] Elevated Cholesterol and Triglycerides [see Warnings and Precautions (5.11) ] Hyponatremia [see Warnings and Precautions (5.12) ] Transaminase Elevations [see Warnings and Precautions (5.13) ] Discontinuation Syndrome [see Warnings and Precautions (5.14) ] Use in Patients with Concomitant Illness [see Warnings and Precautions (5.15) ] Most common adverse reactions (≥5% or greater and twice placebo) were somnolence, increased appetite, weight gain, and dizziness. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Northstar Rx LLC at 1-800-206-7821 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trial 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 trials of another drug and may not reflect the rates observed in practice. The data described below are from clinical trials in which mirtazapine was administered to 2796 patients in phase 2 and 3 clinical studies. The trials consisted of double-blind controlled and open-label studies, inpatient and outpatient studies, fixed dose, and titration studies. Adverse Reactions Leading to Discontinuation of Treatment Approximately 16% of the 453 patients who received mirtazapine in U.S. 6-week placebo-controlled clinical trials discontinued treatment due to an adverse reaction, compared to 7% of the 361 placebo-treated patients in those studies. The most common reactions leading to discontinuation (≥1% and at a rate at least twice that of placebo) are included in Table 2. Table 2: Adverse Reactions (≥1% and at least twice placebo) Leading to Discontinuation of Mirtazapine in 6-Week Clinical Trials in Patients with MDD Mirtazapine (n=453) Placebo (n=361) Somnolence 10.4% 2.2% Nausea 1.5% 0% Common Adverse Reactions The most common adverse reactions (≥5% and twice placebo) associated with the use of mirtazapine are listed in Table 3. Table 3: Adverse Reactions (≥5% and twice placebo) in 6-Week U.S. Clinical Trials of Mirtazapine in Patients with MDD Mirtazapine (n=453) Placebo (n=361) Somnolence 54% 18% Increased Appetite 17% 2% Weight Gain 12% 2% Dizziness 7% 3% Table 4 enumerates adverse reactions that occurred in ≥1% of mirtazapine-treated patients, and were more frequent than the placebo-treated patients, who participated in 6-week, U.S. placebo-controlled trials in which patients were dosed in a range of 5 to 60 mg/day. This table shows the percentage of patients in each group who had at least 1 episode of an adverse reaction at some time during their treatment. Table 4: Adverse Reactions (≥1% and greater than placebo) in 6-Week U.S. Clinical Studies of Mirtazapine in Patients with MDD Mirtazapine (n=453) Placebo (n=361) Body as a Whole Asthenia 8% 5% Flu Syndrome 5% 3% Back Pain 2% 1% Digestive System Dry Mouth 25% 15% Increased Appetite 17% 2% Constipation 13% 7% Metabolic and Nutritional Disorders Weight Gain 12% 2% Peripheral Edema 2% 1% Edema 1% 0% Musculoskeletal System Myalgia 2% 1% Nervous System Somnolence 54% 18% Dizziness 7% 3% Abnormal Drea …

Information for Patients Prescribers or other health professionals should inform patients, their families, and their caregivers about the benefits and risks associated with treatment with mirtazapine tablets and should counsel them in its appropriate use. A patient Medication Guide about “Antidepressant Medicines, Depression and other Serious Mental Illnesses, and Suicidal Thoughts or Actions” is available for mirtazapine tablets. The prescriber or health professional should instruct patients, their families, and their caregivers to read the Medication Guide and should assist them in understanding its contents. Patients should be given the opportunity to discuss the contents of the Medication Guide and to obtain answers to any questions they may have. The complete text of the Medication Guide is reprinted at the end of this document. Patients should be advised of the following issues and asked to alert their prescriber if these occur while taking mirtazapine tablets. Clinical Worsening and Suicide Risk Patients, their families, and their caregivers should be encouraged to be alert to the emergence of anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, mania, other unusual changes in behavior, worsening of depression, and suicidal ideation, especially early during antidepressant treatment and when the dose is adjusted up or down. Families and caregivers of patients should be advised to look for the emergence of such symptoms on a day-to-day basis, since changes may be abrupt. Such symptoms should be reported to the patient's prescriber or health professional, especially if they are severe, abrupt in onset, or were not part of the patient's presenting symptoms. Symptoms such as these may be associated with an increased risk for suicidal thinking and behavior and indicate a need for very close monitoring and possibly changes in the medication. Agranulocytosis Patients who are to receive mirtazapine tablets should be warned about the risk of developing agranulocytosis. Patients should be advised to contact their physician if they experience any indication of infection such as fever, chills, sore throat, mucous membrane ulceration, or other possible signs of infection. Particular attention should be paid to any flu-like complaints or other symptoms that might suggest infection. Interference with Cognitive and Motor Performance Mirtazapine tablets may impair judgment, thinking, and particularly, motor skills, because of its prominent sedative effect. The drowsiness associated with mirtazapine use may impair a patient’s ability to drive, use machines, or perform tasks that require alertness. Thus, patients should be cautioned about engaging in hazardous activities until they are reasonably certain that mirtazapine tablet therapy does not adversely affect their ability to engage in such activities. Completing Course of Therapy While patients may notice improvement with mirtazapine tablet therapy in 1 to 4 weeks, they should be advised to continue therapy as directed. Concomitant Medication Patients should be advised to inform their physician if they are taking, or intend to take, any prescription or over-the-counter drugs, since there is a potential for mirtazapine tablets to interact with other drugs. Patients should be made aware of a potential increased risk for serotonin syndrome if concomitant use of mirtazapine tablets with other serotonergic drugs, including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, buspirone, tryptophan, and St. John's wort, is clinically warranted, particularly during treatment initiation and dose increases. Alcohol The impairment of cognitive and motor skills produced by mirtazapine tablets has been shown to be additive with those produced by alcohol. Accordingly, patients should be advised to avoid alcohol while taking mirtazapine. Pregnancy Patients should be advised to notify their physi …

8 USE IN SPECIFIC POPULATIONS • Geriatric Use: Use with caution in elderly patients. (5.12, 5.15, 8.5) • Renal impairment: Dosage decrease may be needed in patients with moderate to severe renal impairment. (8.6) • Hepatic impairment: Dosage decrease may be needed in patients with hepatic impairment. (8.6) See 17 for PATIENT COUNSELING INFORMATION and Medication Guide Revised: 02/2024 8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to antidepressants during pregnancy. Healthcare providers are encouraged to register patients by calling the National Pregnancy Registry for Antidepressants at 1-844-405-6185 or visiting online at https://womensmentalhealth.org/clinical-and-research-programs/pregnancyregistry/antidepressants/. Risk Summary Prolonged experience with mirtazapine in pregnant women, based on published observational studies and postmarketing reports, has not reliably identified a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. There are risks associated with untreated depression in pregnancy (see Clinical Considerations). In animal reproduction studies, oral administration of mirtazapine to pregnant rats and rabbits during the period of organogenesis revealed no evidence of teratogenic effects up to 20 and 17 times the maximum recommended human dose (MRHD) of 45 mg, respectively, based on mg/m2 body surface area. However, in rats, there was an increase in post implantation loss at 20 times the MRHD based on mg/m2 body surface area. Oral administration of mirtazapine to pregnant rats during pregnancy and lactation resulted in an increase in pup deaths and a decrease in pup birth weights at doses 20 times the MRHD based on mg/m2 body surface area (see Data). The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Women who discontinue antidepressants during pregnancy are more likely to experience a relapse of major depression than women who continue antidepressants. This finding is from a prospective, longitudinal study that followed 201 pregnant women with a history of major depressive disorder who were euthymic and taking antidepressants at the beginning of pregnancy. Consider the risk of untreated depression when discontinuing or changing treatment with antidepressant medication during pregnancy and postpartum. Data Animal Data Mirtazapine was administered orally to pregnant rats and rabbits during the period of organogenesis at doses of 2.5, 15, and 100 mg/kg/day and 2.5, 10, and 40 mg/kg/day, respectively, which are up to 20 and 17 times the maximum recommended human dose (MRHD) of 45 mg based on mg/m2 body surface area, respectively. No evidence of teratogenic effects was observed. However, in rats, there was an increase in post implantation loss in dams treated with mirtazapine at 100 mg/kg/day which is 20 times the MRHD based on mg/m2 body surface area. Oral administration of mirtazapine at doses of 2.5, 15, and 100mg/kg/day to pregnant rats during pregnancy and lactation resulted in an increase in pup deaths during the first 3 days of lactation and a decrease in pup birth weights at 20 times the MRHD based on mg/m2 body surface area. The cause of these deaths is not known. The no effect dose level is 3 times the MRHD based on mg/m2 body surface area. 8.2 Lactation Risk Summary Data from published literature report the presence of mirtazapine in human milk at low levels with relative infant doses for mirtazapine ranging between 0.6 and 2.8% of the maternal weight-adjusted dose (see Data). No adve …

12.1 Mechanism of Action The mechanism of action of mirtazapine for the treatment of major depressive disorder, is unclear. However, its efficacy could be mediated through its activity as an antagonist at central presynaptic α 2 -adrenergic inhibitory auto-receptors and heteroreceptors and enhancing central noradrenergic and serotonergic activity.

11 DESCRIPTION Mirtazapine tablets, USP contain mirtazapine, USP. Mirtazapine has a tetracyclic chemical structure and belongs to the piperazino-azepine group of compounds. It is designated 1,2,3,4,10,14b-hexahydro-2-methylpyrazino [2,1-a] pyrido [2,3-c][2] benzazepine and has the empirical formula of C 17 H 19 N 3 . Its molecular weight is 265.35. The structural formula is the following and it is the racemic mixture: Mirtazapine is a white to creamy white crystalline powder which is practically insoluble in water. Mirtazapine tablets are available for oral administration as scored film-coated tablets containing 15 mg or 30 mg of mirtazapine, and unscored film-coated tablets containing 7.5 mg or 45 mg of mirtazapine. Each tablet contains the following inactive ingredients: colloidal silicon dioxide, corn starch, hydroxypropyl cellulose, hypromellose, lactose monohydrate, magnesium stearate, polyethylene glycol, and titanium dioxide. The 7.5 mg tablets also contain sunset yellow FCF lake and Allura red AC lake. The 15 mg tablets also contain iron oxide yellow, quinoline yellow lake and sunset yellow FCF lake. The 30 mg tablets also contain ferric oxide yellow, ferric oxide red and ferrosoferric oxide/iron oxide black. FDA approved dissolution method differs from the USP dissolution testing. Chemical Structure

OVERDOSAGE Human Experience There is very limited experience with mirtazapine tablets overdose. In premarketing clinical studies, there were eight reports of mirtazapine tablets overdose alone or in combination with other pharmacological agents. The only drug overdose death reported while taking mirtazapine tablets was in combination with amitriptyline and chlorprothixene in a non-US clinical study. Based on plasma levels, the mirtazapine tablets dose taken was 30 to 45 mg, while plasma levels of amitriptyline and chlorprothixene were found to be at toxic levels. All other premarketing overdose cases resulted in full recovery. Signs and symptoms reported in association with overdose included disorientation, drowsiness, impaired memory, and tachycardia. There were no reports of ECG abnormalities, coma, or convulsions following overdose with mirtazapine tablets alone. However, based on postmarketing reports, there is a possibility of more serious outcomes (including fatalities) at dosages much higher than the therapeutic dose, especially with mixed overdoses. In these cases, QT prolongation and Torsades de Pointes have also been reported (see PRECAUTIONS, Drug Interactions and ADVERSE REACTIONS sections). Overdose Management Treatment should consist of those general measures employed in the management of overdose with any drug effective in the treatment of major depressive disorder. Ensure an adequate airway, oxygenation, and ventilation. Monitor ECG parameters (including cardiac rhythm) and vital signs. General supportive and symptomatic measures are also recommended. Induction of emesis is not recommended. Gastric lavage with a large-bore orogastric tube with appropriate airway protection, if needed, may be indicated if performed soon after ingestion, or in symptomatic patients. Activated charcoal should be administered. There is no experience with the use of forced diuresis, dialysis, hemoperfusion, or exchange transfusion in the treatment of mirtazapine overdosage. No specific antidotes for mirtazapine are known. In managing overdosage, consider the possibility of multiple-drug involvement. The physician should consider contacting a poison control center for additional information on the treatment of any overdose. Telephone numbers for certified poison control centers are listed in the Physicians’ Desk Reference (PDR).

16 HOW SUPPLIED/STORAGE AND HANDLING Mirtazapine tablets, USP are supplied as: 7.5 mg Tablets – White, biconvex, capsule shaped film coated tablets with “11” debossed on one side and “A” debossed on the other side. Bottles of 30 NDC 13107-001-30 Bottles of 60 NDC 13107-001-60 Bottles of 90 NDC 13107-001-90 Bottles of 100 NDC 13107-001-01 Bottles of 500 NDC 13107-001-05 15 mg Tablets – Yellow, biconvex, capsule shaped film coated tablets with a score line in between “0” and “8” on one side and “A” debossed on the other side. Bottles of 30 (120cc container) NDC 13107-031-30 Bottles of 30 NDC 13107-031-34 Bottles of 60 NDC 13107-031-60 Bottles of 90 NDC 13107-031-90 Bottles of 100 NDC 13107-031-01 Bottles of 500 NDC 13107-031-05 30 Unit-of-use packaging NDC 13107-031-32 30 mg Tablets – Reddish brown, biconvex, capsule shaped film coated tablets with a score line in between “0” and “9” on one side and “A” debossed on the other side. Bottles of 30 (120cc container) NDC 13107-003-30 Bottles of 30 NDC 13107-003-34 Bottles of 60 NDC 13107-003-60 Bottles of 90 NDC 13107-003-90 Bottles of 100 NDC 13107-003-01 Bottles of 500 NDC 13107-003-05 30 Unit-of-use packaging NDC 13107-003-32 45 mg Tablets – White, biconvex, capsule shaped film coated tablets with “10” debossed on one side and “A” debossed on the other side. Bottles of 30 NDC 13107-032-34 Bottles of 60 NDC 13107-032-60 Bottles of 90 NDC 13107-032-90 Bottles of 100 NDC 13107-032-01 Bottles of 500 NDC 13107-032-05 30 Unit-of-use packaging NDC 13107-032-32 Storage Store at 25°C (77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature]. Protect from light and moisture.