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Mirtazapine

FDA Drug Information • Also known as: Mirtazapine, Remeron, Remeronsoltab

Brand Names
Mirtazapine, Remeron, Remeronsoltab
Dosage Form
POWDER
Product Type
BULK INGREDIENT

⚠ Boxed Warning (Black Box)

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) ] . Mirtazapine tablets are 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. Increased risk of suicidal thoughts and behavior in pediatric and young adult patients taking antidepressants. Closely monitor all antidepressant-treated patients for clinical worsening and emergence of suicidal thoughts and behaviors. Mirtazapine tablets are not approved for use in pediatric patients. ( 5.1 , 8.4 )

Description

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 molecular 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, USP are available for oral administration as scored film-coated tablets containing 15 or 30 mg of mirtazapine USP, and unscored film-coated tablets containing 7.5 or 45 mg of mirtazapine USP. Each tablet contains the following inactive ingredients: corn starch, colloidal silicon dioxide, hydroxypropyl cellulose, hypromellose, lactose monohydrate, magnesium stearate, and titanium dioxide. In addition, the 15 mg contains iron oxide yellow and 30 mg contains iron oxide red, iron oxide black, and iron oxide yellow. Chemical Structure

What Is Mirtazapine Used For?

1 INDICATIONS AND USAGE Mirtazapine tablets are indicated for the treatment of major depressive disorder (MDD) in adults [see Clinical Studies (14) ]. Mirtazapine tablets are indicated for the treatment of major depressive disorder (MDD) in adults. ( 1 )

Dosage and Administration

2 DOSAGE AND ADMINISTRATION

  • Starting dose: 15 mg once daily; may increase up to maximum recommended dose of 45 mg once daily. ( 2.1 )
  • Administer orally once daily, preferably in the evening prior to sleep. ( 2.1 )
  • Reduce dose gradually when discontinuing mirtazapine tablets. ( 2.6 , 5.13 ) 2.1 Recommended Dosage The recommended starting dose of mirtazapine tablets is 15 mg once daily, administered orally, preferably in the evening prior to sleep. If patients do not have an adequate response to the initial 15 mg dose, increase the dose up to a maximum of 45 mg per day. Dose changes should not be made in intervals of less than 1 to 2 weeks to allow sufficient time for evaluation of response to a given dose [see Clinical Pharmacology (12.3) ]. 2.3 Screen for Bipolar Disorder Prior to Starting Mirtazapine Tablets Prior to initiating treatment with mirtazapine tablets or another antidepressant, screen patients for a personal or family history of bipolar disorder, mania, or hypomania [see Warnings and Precautions (5.8) ]. 2.4 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 mirtazapine tablets. In addition, at least 14 days must elapse after stopping mirtazapine tablets before starting an MAOI antidepressant [see Contraindications (4) and Warnings and Precautions (5.3) ]. 2.5 Dosage Modifications Due to Drug Interactions Strong CYP3A Inducers An increase in dosage of mirtazapine tablets may be needed with concomitant strong CYP3A inducer (e.g., carbamazepine, phenytoin, rifampin) use. Conversely, a decrease in dosage of mirtazapine tablets may be needed if the CYP3A inducer is discontinued [see Drug Interactions (7) ]. Strong CYP3A Inhibitors A decrease in dosage of mirtazapine tablets may be needed with concomitant use of strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin). Conversely, an increase in dosage of mirtazapine tablets may be needed if the CYP3A4 inhibitor is discontinued [see Drug Interactions (7) ]. Cimetidine A decrease in dosage of mirtazapine tablets may be needed with concomitant use of cimetidine. Conversely, an increase in dosage of mirtazapine tablets may be needed if cimetidine is discontinued [see Drug Interactions (7) ]. 2.6 Discontinuation of Mirtazapine Tablets Treatment Adverse reactions may occur upon discontinuation or dose reduction of mirtazapine tablets [see Warnings and Precautions (5.13) ]. Gradually reduce the dosage of mirtazapine tablets rather than stopping abruptly whenever possible.

    • Side Effects (Adverse Reactions)

    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) ]
  • Increased Appetite and Weight Gain [see Warnings and Precautions (5.6) ]
  • Somnolence [see Warnings and Precautions (5.7) ]
  • Activation of Mania or Hypomania [see Warnings and Precautions (5.8) ]
  • Seizures [see Warnings and Precautions (5.9) ]
  • Elevated Cholesterol and Triglycerides [see Warnings and Precautions (5.10) ]
  • Hyponatremia [see Warnings and Precautions (5.11) ]
  • Transaminase Elevations [see Warnings and Precautions (5.12) ]
  • Discontinuation Syndrome [see Warnings and Precautions (5.13) ]
  • Use in Patients with Concomitant Illness [see Warnings and Precautions (5.14) ] 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 Rising Health, LLC at 1-833-395-6928 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 Dreams 4% 1% Thinking Abnormal 3% 1% Tremor 2% 1% Confusion 2% 0%...

    • Drug Interactions

    7 DRUG INTERACTIONS Table 5 includes clinically important drug interactions with mirtazapine [see Clinical Pharmacology (12.3) ]. Table 5: Clinically Important Drug Interactions with Mirtazapine Monoamine Oxidase Inhibitors (MAOIs) Clinical Impact The concomitant use of serotonergic drugs, including mirtazapine, and MAOIs increases the risk of serotonin syndrome. Intervention Mirtazapine is contraindicated in patients taking MAOIs, including MAOIs such as linezolid or intravenous methylene blue [see Dosage and Administration (2.4) , Contraindications (4) , Warnings and Precautions (5.3) ]. Examples selegiline, tranylcypromine, isocarboxazid, phenelzine, linezolid, methylene blue Other Serotonergic Drugs Clinical Impact The concomitant use of serotonergic drugs with mirtazapine increases the risk of serotonin syndrome. Intervention Monitor patients for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increases. If serotonin syndrome occurs, consider discontinuation of mirtazapine and/or concomitant serotonergic drugs [see Warnings and Precautions (5.3) ]. Examples SSRIs, SNRIs, triptans, tricyclic antidepressants, fentanyl, lithium, amphetamines, St. John’s Wort, tramadol, tryptophan, buspirone Strong CYP3A Inducers Clinical Impact The concomitant use of strong CYP3A inducers with mirtazapine decreases the plasma concentration of mirtazapine [see Clinical Pharmacology (12.3) ]. Intervention Increase the dose of mirtazapine if needed with concomitant CYP3A inducer use. Conversely, a decrease in dosage of mirtazapine may be needed if the CYP3A inducer is discontinued [see Dosage and Administration (2.5) ]. Examples phenytoin, carbamazepine, rifampin Strong CYP3A Inhibitors Clinical Impact The concomitant use of strong CYP3A inhibitors with mirtazapine may increase the plasma concentration of mirtazapine [see Clinical Pharmacology (12.3) ]. Intervention Decrease the dose of mirtazapine if needed with concomitant strong CYP3A inhibitor use. Conversely, an increase in dosage of mirtazapine may be needed if the CYP3A inhibitor is discontinued [see Dosage and Administration (2.5) ]. Examples itraconazole, ritonavir, nefazodone Cimetidine Clinical Impact The concomitant use of cimetidine, a CYP1A2, CYP2D6, and CYP3A inhibitor, with mirtazapine may increase the plasma concentration of mirtazapine [see Clinical Pharmacology (12.3) ]. Intervention Decrease the dose of mirtazapine if needed with concomitant cimetidine use. Conversely, an increase in dosage of mirtazapine may be needed if cimetidine is discontinued [see Dosage and Administration (2.5) ]. Benzodiazepines and Alcohol Clinical Impact The concomitant use of benzodiazepines or alcohol with mirtazapine increases the impairment of cognitive and motor skills produced by mirtazapine alone. Intervention Avoid concomitant use of benzodiazepines and alcohol with mirtazapine [see Warnings and Precautions (5.7) , Clinical Pharmacology (12.3) ]. Examples...

    Contraindications

    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 Stevens-Johnson syndrome, bullous dermatitis, erythema multiforme and toxic epidermal necrolysis have been reported following the use of mirtazapine tablets [see 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 )

    • Pregnancy and Breastfeeding

    8.1 Pregnancy Reproduction studies in pregnant rats and rabbits at doses up to 100 mg/kg and 40 mg/kg, respectively [20 and 17 times the maximum recommended human dose (MRHD) on an mg/m 2 basis, respectively], have revealed no evidence of teratogenic effects. However, in rats, there was an increase in post-implantation losses in dams treated with mirtazapine. There was an increase in pup deaths during the first 3 days of lactation and a decrease in pup birth weights. The cause of these deaths is not known. The effects occurred at doses that were 20 times the MRHD, but not at 3 times the MRHD, on an mg/m 2 basis. There are no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, mirtazapine should be used during pregnancy only if clearly needed.

    8.3 Nursing Mothers Mirtazapine may be excreted in breast milk. Exercise caution when administering mirtazapine to nursing women.

    Overdosage

    10 OVERDOSAGE Human Experience In premarketing clinical studies, there were reports of mirtazapine overdose alone or in combination with other pharmacological agents. Signs and symptoms reported in association with overdose included disorientation, drowsiness, impaired memory, and tachycardia. Based on postmarketing reports, serious outcomes (including fatalities) may occur at dosages higher than the recommended doses, especially with mixed overdoses. In these cases, QT prolongation and Torsades de Pointes have also been reported [see Warnings and Precautions (5.5) , Adverse Reactions (6.2) , and Drug Interactions (7) ]. Overdose Management No specific antidotes for mirtazapine are known. Contact Poison Control (1-800-222-1222) for the latest recommendations.

    How Supplied

    16 HOW SUPPLIED/STORAGE AND HANDLING Mirtazapine tablets, USP are supplied as: 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 NDC 71205-481-30 Bottles of 60 NDC 71205-481-60 Bottles of 90 NDC 71205-481-90 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.

    About This Information

    This drug information is sourced from FDA-approved labeling via the openFDA database. It is intended for educational and reference purposes only. This is not medical advice. Always consult your healthcare provider before making decisions about medication. Drug information may be updated by the FDA; check with your pharmacist for the most current information.

    What are side effects?

    Side effects are unwanted reactions that can occur when taking a medication. They range from mild (headache, nausea) to severe (allergic reactions, organ damage). Not everyone experiences side effects, and severity varies. Report any concerning side effects to your doctor.

    What are drug interactions?

    Drug interactions occur when a medication is affected by another drug, food, or supplement. Interactions can make medications less effective or cause dangerous side effects. Always tell your doctor about all medications and supplements you take.