Mirtazapine

Serious warning

The strongest warning the FDA requires. It is printed in a box at the top of the label.

Quoted from the official label, section “Boxed Warning”.

Do not take it if

Quoted from the official label, section “Contraindications”.

How to take it

These directions are for this exact strength and form. Another one is different.

• 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 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 has an elimination half-life of approximately 20 to 40 hours; therefore, dose changes should not be made at intervals of less than 1 to 2 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 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 tablets 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.
• The clinician should, nevertheless, be aware of the possibility of emergent symptoms of serotonin syndrome with such use (see WARNINGS ).
• Discontinuation of Mirtazapine Tablets Treatment Symptoms associated with the discontinuation or dose reduction of mirtazapine tablets have been reported.
• Patients should be monitored for these and other symptoms when discontinuing treatment or during dosage reduction.
• A gradual reduction in the dose over several weeks, rather than abrupt cessation, is recommended whenever possible.
• If intolerable symptoms occur following a decrease in the dose or upon discontinuation of treatment, dose titration should be managed on the basis of the patient’s clinical response (see PRECAUTIONS and ADVERSE REACTIONS ).
• Information for Patients Patients should be advised that taking mirtazapine tablets can cause mild pupillary dilation, which in susceptible individuals, can lead to an episode of angle-closure glaucoma.
• Pre-existing glaucoma is almost always open-angle glaucoma because angle-closure glaucoma, when diagnosed, can be treated definitively with iridectomy.
• Open-angle glaucoma is not a risk factor for 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.

Quoted from the official label, section “Dosage & Administration”.

Other warnings

Quoted from the official label, section “Warnings”.

Pregnancy and breastfeeding

Quoted from the official label, section “OTC — Pregnancy or Breast Feeding”.

Other medicines

Quoted from the official label, section “Drug Interactions”.

If you take too much

In an emergency, call your local emergency number or a poison control centre.

Quoted from the official label, section “Overdosage”.

Misuse and dependence

Quoted from the official label, section “Drug Abuse and Dependence”.

Use in children

• Safety and effectiveness in the pediatric population have not been established (see BOXED WARNING and WARNINGS:
• Clinical Worsening and Suicide Risk ).
• Two placebo-controlled trials in 258 pediatric patients with MDD have been conducted with mirtazapine tablets, and the data were not sufficient to support a claim for use in pediatric patients.
• Anyone considering the use of mirtazapine tablets in a child or adolescent must balance the potential risks with the clinical need.
• In an 8-week-long pediatric clinical trial of doses between 15 to 45 mg/day, 49% of mirtazapine-treated patients had a weight gain of at least 7%, compared to 5.7% of placebo-treated patients.
• The mean increase in weight was 4 kg (2 kg SD) for mirtazapine-treated patients versus 1 kg (2 kg SD) for placebo-treated patients (see PRECAUTIONS:
• Increased Appetite/Weight Gain ).

Quoted from the official label, section “Pediatric Use”.

Use in older people

• Approximately 190 elderly individuals (≥ 65 years of age) participated in clinical studies with mirtazapine tablets.
• This drug is known to be substantially excreted by the kidney (75%), and the risk of decreased clearance of this drug is greater in patients with impaired renal function.
• Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection.
• Sedating drugs may cause confusion and over-sedation in the elderly.
• No unusual adverse age-related phenomena were identified in this group.
• Pharmacokinetic studies revealed a decreased clearance in the elderly.
• Caution is indicated in administering mirtazapine to elderly patients (see CLINICAL PHARMACOLOGY and DOSAGE AND ADMINISTRATION ).

Quoted from the official label, section “Geriatric Use”.

Side effects

• Associated with Discontinuation of Treatment Approximately 16% of the 453 patients who received mirtazapine tablets in US 6-week controlled clinical trials discontinued treatment due to an adverse experience, compared to 7% of the 361 placebo-treated patients in those studies.
• The most common events (≥ 1%) associated with discontinuation and considered to be drug related (i.e., those events associated with dropout at a rate at least twice that of placebo) are included in Table 2.
• Table 2:
• Common Adverse Events Associated With Discontinuation of Treatment in 6-Week U.S.
• Mirtazapine Trials Adverse Event Percentage of Patients Discontinuing With Adverse Event Mirtazapine (n=453) Placebo (n=361) Somnolence 10.4% 2.2% Nausea 1.5% 0% Commonly Observed Adverse Events in U.S.
• Controlled Clinical Trials The most commonly observed adverse events associated with the use of mirtazapine tablets (incidence of 5% or greater) and not observed at an equivalent incidence among placebo-treated patients (mirtazapine incidence at least twice that for placebo) are listed in Table 3.
• Table 3:
• Common Treatment – Emergent Adverse Events Associated With the Use of Mirtazapine in 6-Week U.S.
• Trials Adverse Event Percentage of Patients Reporting Adverse Event Mirtazapine (n=453) Placebo (n=361) Somnolence 54% 18% Increased Appetite 17% 2% Weight Gain 12% 2% Dizziness 7% 3% Adverse Events Occurring at an Incidence of 1% or More Among Mirtazapine-Treated Patients Table 4 enumerates adverse events that occurred at an incidence of 1% or more, and were more frequent than in the placebo group, among mirtazapine tablets-treated patients who participated in short-term US 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 event at some time during their treatment.
• Reported adverse events were classified using a standard COSTART-based dictionary terminology.
• The prescriber should be aware that these figures cannot be used to predict the incidence of side effects in the course of usual medical practice where patient characteristics and other factors differ from those which prevailed in the clinical trials.
• Similarly, the cited frequencies cannot be compared with figures obtained from other investigations involving different treatments, uses, and investigators.
• The cited figures, however, do provide the prescribing physician with some basis for estimating the relative contribution of drug and nondrug factors to the side-effect incidence rate in the population studied.
• Table 4: Incidence of Adverse Clinical Experiences 1 (≥1%) in Short-Term U.S.
• Controlled Studies Body System Adverse Clinical Experience Mirtazapine (n=453) Placebo (n=361) 1 Events reported by at least 1% of patients treated with mirtazapine are included, except the following events, which had an incidence on placebo greater than or equal to mirtazapine:
• headache, infection, pain, chest pain, palpitation, tachycardia, postural hypotension, nausea, dyspepsia, diarrhea, flatulence, insomnia, nervousness, libido decreased, hypertonia, pharyngitis, rhinitis, sweating, amblyopia, tinnitus, taste perversion.
• 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% Respiratory System Dyspnea 1% 0% Urogenital System Urinary Frequency 2% 1% ECG Changes The electrocardiograms for 338 patients who received mirtazapine tablets and 261 patients who received placebo in 6-week, placebo-controlled trials were analyzed.
• Prolongation in QTc ≥ 500 msec was not observed among mirtazapine-treated patients; mean change in QTc was +1.6 msec for mirtazapine and -3.1 msec for placebo.
• Mirtazapine was associated with a mean increase in heart rate of 3.4 bpm, compared to 0.8 bpm for placebo.
• The clinical significance of these changes is unknown.
• The effect of mirtazapine on QTc interval was assessed in a clinical randomized trial with placebo and positive (moxifloxacin) controls involving 54 healthy volunteers using exposure response analysis.
• This trial showed a positive relationship between mirtazapine concentrations and prolongation of the QTc interval.
• However, the degree of QT prolongation observed with both 45 mg (therapeutic) and 75 mg (supratherapeutic) doses of mirtazapine was not at a level generally considered to be clinically meaningful.
• Other Adverse Events Observed During the Premarketing Evaluation of Mirtazapine During its premarketing assessment, multiple doses of mirtazapine tablets were administered to 2796 patients in clinical studies.
• The conditions and duration of exposure to mirtazapine varied greatly, and included (in overlapping categories) open and double-blind studies, uncontrolled and controlled studies, inpatient and outpatient studies, fixed-dose and titration studies.
• Untoward events associated with this exposure were recorded by clinical investigators using terminology of their own choosing.
• Consequently, it is not possible to provide a meaningful estimate of the proportion of individuals experiencing adverse events without first grouping similar types of untoward events into a smaller number of standardized event categories.
• In the tabulations that follow, reported adverse events were classified using a standard COSTART-based dictionary terminology.
• The frequencies presented, therefore, represent the proportion of the 2796 patients exposed to multiple doses of mirtazapine who experienced an event of the type cited on at least 1 occasion while receiving mirtazapine.
• All reported events are included except those already listed in Table 4, those adverse experiences subsumed under COSTART terms that are either overly general or excessively specific so as to be uninformative, and those events for which a drug cause was very remote.
• It is important to emphasize that, although the events reported occurred during treatment with mirtazapine, they were not necessarily caused by it.
• Events are further categorized by body system and listed in order of decreasing frequency according to the following definitions:
• frequent adverse events are those occurring on 1 or more occasions in at least 1/100 patients; infrequent adverse events are those occurring in 1/100 to 1/1000 patients; rare events are those occurring in fewer than 1/1000 patients.
• Only those events not already listed in Table 4 appear in this listing.
• Events of major clinical importance are also described in the WARNINGS and PRECAUTIONS sections.
• Body as a Whole:
• frequent:
• malaise, abdominal pain, abdominal syndrome acute; infrequent:
• chills, fever, face edema, ulcer, photosensitivity reaction, neck rigidity, neck pain, abdomen enlarged; rare:
• cellulitis, chest pain substernal.
• Cardiovascular System :
• frequent:
• hypertension, vasodilatation; infrequent:
• angina pectoris, myocardial infarction, bradycardia, ventricular extrasystoles, syncope, migraine, hypotension; rare:
• atrial arrhythmia, bigeminy, vascular headache, pulmonary embolus, cerebral ischemia, cardiomegaly, phlebitis, left heart failure.
• Digestive System:
• frequent:
• vomiting, anorexia; infrequent:
• eructation, glossitis, cholecystitis, nausea and vomiting, gum hemorrhage, stomatitis, colitis, liver function tests abnormal; rare:
• tongue discoloration, ulcerative stomatitis, salivary gland enlargement, increased salivation, intestinal obstruction, pancreatitis, aphthous stomatitis, cirrhosis of liver, gastritis, gastroenteritis, oral moniliasis, tongue edema.
• Endocrine System: rare: goiter, hypothyroidism.
• Hemic and Lymphatic System:
• rare:
• lymphadenopathy, leukopenia, petechia, anemia, thrombocytopenia, lymphocytosis, pancytopenia.
• Metabolic and Nutritional Disorders:
• frequent:
• thirst; infrequent:
• dehydration, weight loss; rare:
• gout, SGOT increased, healing abnormal, acid phosphatase increased, SGPT increased, diabetes mellitus, hyponatremia.
• Musculoskeletal System:
• frequent:
• myasthenia, arthralgia; infrequent:
• arthritis, tenosynovitis; rare:
• pathologic fracture, osteoporosis fracture, bone pain, myositis, tendon rupture, arthrosis, bursitis.
• Nervous System:
• frequent:
• hypesthesia, apathy, depression, hypokinesia, vertigo, twitching, agitation, anxiety, amnesia, hyperkinesia, paresthesia; infrequent:
• ataxia, delirium, delusions, depersonalization, dyskinesia, extrapyramidal syndrome, libido increased, coordination abnormal, dysarthria, hallucinations, manic reaction, neurosis, dystonia, hostility, reflexes increased, emotional lability, euphoria, paranoid reaction; rare:
• aphasia, nystagmus, akathisia (psychomotor restlessness), stupor, dementia, diplopia, drug dependence, paralysis, grand mal convulsion, hypotonia, myoclonus, psychotic depression, withdrawal syndrome, serotonin syndrome.
• Respiratory System:
• frequent:
• cough increased, sinusitis; infrequent:
• epistaxis, bronchitis, asthma, pneumonia; rare:
• asphyxia, laryngitis, pneumothorax, hiccup.
• Skin and Appendages:
• frequent:
• pruritus, rash; infrequent:
• acne, exfoliative dermatitis, dry skin, herpes simplex, alopecia; rare:
• urticaria, herpes zoster, skin hypertrophy, seborrhea, skin ulcer.
• Special Senses:
• infrequent:
• eye pain, abnormality of accommodation, conjunctivitis, deafness, keratoconjunctivitis, lacrimation disorder, angle-closure glaucoma, hyperacusis, ear pain; rare:
• blepharitis, partial transitory deafness, otitis media, taste loss, parosmia.
• Urogenital System:
• frequent:
• urinary tract infection; infrequent:
• kidney calculus, cystitis, dysuria, urinary incontinence, urinary retention, vaginitis, hematuria, breast pain, amenorrhea, dysmenorrhea, leukorrhea, impotence; rare:
• polyuria, urethritis, metrorrhagia, menorrhagia, abnormal ejaculation, breast engorgement, breast enlargement, urinary urgency.
• Other Adverse Events Observed During Postmarketing Evaluation of Mirtazapine Adverse events reported since market introduction, which were temporally (but not necessarily causally) related to mirtazapine therapy, include cases of the ventricular arrhythmia Torsades de Pointes.
• In the majority of these cases, however, concomitant drugs were implicated.
• Cases of severe skin reactions, including Stevens-Johnson syndrome, bullous dermatitis, erythema multiforme and toxic epidermal necrolysis have also been reported.
• Increased creatine kinase blood levels and rhabdomyolysis have also been reported.

Quoted from the official label, section “Adverse Reactions”.

What to discuss with your doctor

• 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.
• 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.
• 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 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 may impair judgement, 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 therapy does not adversely affect their ability to engage in such activities.
• Completing Course of Therapy While patients may notice improvement with mirtazapine 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 to interact with other drugs.
• Patients should be made aware of a potential increased risk for serotonin syndrome if concomitant use of mirtazapine 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 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 physician if they become pregnant or intend to become pregnant during mirtazapine therapy.
• Nursing Patients should be advised to notify their physician if they are breast feeding an infant.

Quoted from the official label, section “Patient Counseling Information”.

What it looks like and how it is packed

• 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 57237-007-30 Bottles of 500 NDC 57237-007-05 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 NDC 57237-008-30 Bottles of 500 NDC 57237-008-05 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 NDC 57237-009-30 Bottles of 500 NDC 57237-009-05 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 57237-010-30 Bottles of 500 NDC 57237-010-05 Storag e
• 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.
• Dispense with medication guide available at :
• http://www.risingpharma.com/med-guides.html Distributed by:
• Rising Health, LLC Saddle Brook, NJ 07663 Made in India Code:
• TS/DRUGS/19/1993 Revised:
• 08/2017

Quoted from the official label, section “How Supplied”.

What is in it

• Mirtazapine tablets, USP are an orally administered drug.
• 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] benzazepine and has the empirical formula of C 17 H 19 N 3 .
• Its molecular weight is 265.36.
• The structural formula is the following and it is the racemic mixture:
• Mirtazapine USP is a white to creamy white crystalline powder which is slightly soluble in water.
• Mirtazapine tablets, USP are supplied 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 also contains corn starch, hydroxypropyl cellulose, magnesium stearate, colloidal silicon dioxide, lactose monohydrate, hypromellose, 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

Quoted from the official label, section “Description”.

Ingredients people check for

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Same active substance, strength and form in other countries

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Details

Source: NDC Directory · 2026-09-13 · not reviewed by a clinician

Source: US Food and Drug Administration, NDC Directory. Reuse terms: US government work (FDA).

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Other strengths and forms

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Same active substance

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