mirtazapine

ROUTE	ONSET	PEAK	DURATION
PO	1–2 wk	6 wk or more	unknown

Contraindicated in:

Hypersensitivity;
Concurrent use of MAO inhibitors or MAO-like drugs (linezolid or methylene blue).

Use Cautiously in:

History of seizures;
History of suicide attempt;
May ↑ risk of suicide attempt/ideation especially during early treatment or dose adjustment; this risk appears to be greater in adolescents or children;
History of mania/hypomania;
Renal impairment;
Hepatic impairment;
Angle-closure glaucoma;
OB: Other antidepressants are preferred in pregnancy;
Lactation: Other antidepressants are preferred when breastfeeding;
Pedi: Safety and effectiveness in children not established;
Geri: Appears on Beers list. May worsen or cause syndrome of inappropriate antidiuretic hormone (SIADH) secretion and/or hyponatremia in older adults. Use with caution in older adults and closely monitor sodium concentrations when starting therapy or ↑ dose.

Adv. Reactions/Side Effects ⬆ ⬇

Derm: BULLOUS DERMATITIS, DRUG REACTION WITH EOSINOPHILIA AND SYSTEMIC SYMPTOMS (DRESS), ERYTHEMA MULTIFORME, pruritus, rash, STEVENS-JOHNSON SYNDROME (SJS), TOXIC EPIDERMAL NECROLYSIS (TEN)

EENT: sinusitis

Endo: SIADH

F and E: ↑thirst, hyponatremia

GI: constipation, dry mouth, ↑liver enzymes, abdominal pain, anorexia, nausea, vomiting

GU: urinary frequency

Hemat: AGRANULOCYTOSIS

Metab: ↑appetite, weight gain, hypercholesterolemia, hypertriglyceridemia

MS: arthralgia, back pain, myalgia

Neuro: drowsiness, abnormal dreams, abnormal thinking, agitation, akathisia, anxiety, apathy, confusion, dizziness, hyperkinesia, hypoesthesia, malaise, NEUROLEPTIC MALIGNANT SYNDROME (NMS), SUICIDAL THOUGHTS/BEHAVIORS, twitching, weakness

Resp: cough, dyspnea

Misc: flu-like syndrome, SEROTONIN SYNDROME

Interactions ⬆ ⬇

Drug-drug:

May cause hypertension, seizures, and death when used with MAO inhibitors; do not use within 14 days of MAO inhibitor therapy.
Concurrent use with MAO-inhibitor-like drugs, such as linezolid or methylene blue, may ↑ risk of serotonin syndrome; concurrent use contraindicated; do not start therapy in patients receiving linezolid or methylene blue; if linezolid or methylene blue need to be started in a patient receiving mirtazapine, immediately discontinue mirtazapine and monitor for signs/symptoms of serotonin syndrome for 2 wk or until 24 hr after last dose of linezolid or methylene blue, whichever comes first (may resume mirtazapine therapy 24 hr after last dose of linezolid or methylene blue).
Drugs that affect serotonergic neurotransmitter systems, including tricyclic antidepressants, SNRIs, fentanyl, buspirone, tramadol, and triptans, may ↑ risk of serotonin syndrome.
↑risk of CNS depression with other CNS depressants, including alcohol and benzodiazepines.
Ketoconazole, cimetidine, clarithromycin, erythromycin, itraconazole, nefazodone, nelfinavir, or ritonavir may ↑ levels and risk of toxicity.
Phenobarbital, phenytoin, carbamazepine, rifampin, or rifabutin may ↓ levels and effectiveness; may need to ↑ mirtazapine dose.
May ↑ risk of bleeding from warfarin.

Drug-Natural Products:

Kava-kava, valerian, skullcap, chamomile, or hops can ↑ risk of CNS depression.
↑risk of serotonin syndrome with St. John’s wort and SAMe.

Route/Dosage ⬆ ⬇

PO (Adults ): 15 mg/day as a single bedtime dose initially; may be ↑ every 1–2 wk up to 45 mg/day.

Availability ⬆ ⬇

(Generic available)

Tablets: 7.5 mg; 15 mg; 30 mg; 45 mg
Orally disintegrating tablets orange flavor: 15 mg; 30 mg; 45 mg

Assessment ⬆ ⬇

Assess mental status (orientation, mood, behavior) frequently.
Assess for suicidal tendencies, especially during early therapy. Restrict amount of drug available to patient. Risk may be ↑ in adults ≤24 yr. After starting therapy, young adults should be seen by health care provider face-to-face at least weekly for 4 wk, then every other wk for next 4 wk, then at 12 wk, and then on advice of health care provider thereafter.
Assess weight and BMI initially and throughout therapy. For overweight/obese individuals, obtain fasting blood glucose and cholesterol levels. Refer as appropriate for nutritional/weight management and medical management.
Monitor BP and HR periodically during initial therapy. Report significant changes.
Monitor for seizure activity in patients with a history of seizures or alcohol abuse. Institute seizure precautions.
Assess skin periodically during therapy. Severe skin reactions, including DRESS, SJS, bullous dermatitis, erythema multiforme, and TEN, may occur. If signs/symptoms of severe skin reactions occur, discontinue mirtazapine immediately.
Assess for serotonin syndrome (mental changes [agitation, hallucinations, coma], autonomic instability [tachycardia, labile BP, hyperthermia], neuromuscular aberrations [hyperreflexia, incoordination], GI symptoms [nausea, vomiting, diarrhea]), especially in patients taking other serotonergic drugs (SSRIs, SNRIs, triptans).
Monitor for development of NMS (fever, respiratory distress, tachycardia, seizures, diaphoresis, hypertension or hypotension, pallor, tiredness). If signs/symptoms of NMS occur, discontinue mirtazapine and notify health care provider immediately.

Lab Test Considerations:

Assess CBC, liver function, and cholesterol/triglyceride levels before and periodically during therapy.

Implementation ⬆ ⬇

Do not confuse Remeron with Rozerem.
PO: Administer with or without food at bedtime to minimize excessive drowsiness or dizziness.
Orally disintegrating tablets: Do not attempt to push through foil backing; with dry hands, peal back backing and remove tablet. Immediately place tablet on tongue; tablet will dissolve in seconds; then swallow with saliva. Administration with liquid is not necessary.

Patient/Family Teaching ⬆ ⬇

Explain purpose and side effects of medication to patient. Advise patient to read Patient Information before starting therapy. Instruct patient to take as directed. Take missed doses as soon as remembered; if almost time for next dose, skip missed dose and return to regular schedule. If single bedtime dose regimen is used, do not take missed dose in morning, but consult health care provider. Do not discontinue abruptly; gradual dose ↓ may be required.
Advise patient to notify health care provider of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care provider before taking other medications, especially St. John's wort.
May cause drowsiness and dizziness. Caution patient to avoid driving and other activities requiring alertness until response to drug is known.
Advise patient, family, and caregivers to look for suicidality, especially during early therapy or dose changes. Notify health care provider immediately if thoughts about suicide or dying, attempts to commit suicide, new or worse depression or anxiety, agitation or restlessness, panic attacks, insomnia, new or worse irritability, aggressiveness, acting on dangerous impulses, mania, or other changes in mood or behavior occur.
Encourage patient and caregivers to be alert for emergence of anxiety, agitation, panic attacks, insomnia, irritability, hostility, impulsivity, akathisia, hypomania, or mania, especially during early antidepressant therapy. Assess symptoms on a day-to-day basis, as changes may be abrupt. If these symptoms occur, notify health care provider.
Caution patient to change positions slowly to minimize orthostatic hypotension.
Advise patient to avoid alcohol or other CNS depressant drugs during and for ≥3–7 days after therapy has been discontinued.
Instruct patient to notify health care provider of signs and symptoms of serotonin syndrome (mental status changes [agitation, hallucinations, coma], autonomic instability [tachycardia, labile BP, hyperthermia], neuromuscular aberrations [hyperreflexia, incoordination], gastrointestinal symptoms [nausea, vomiting, diarrhea]) or rash occur.
Advise patient to notify health care provider if dry mouth, urinary retention, or constipation occurs. Frequent rinses, good oral hygiene, and sugarless candy or gum may diminish dry mouth. An ↑ in fluid intake, fiber, and exercise may prevent constipation.
Inform patient of need to monitor dietary intake. ↑ in appetite may lead to undesired weight gain.
Advise patient to notify health care provider of medication regimen before treatment or surgery.
Rep: Advise women of reproductive potential to notify health care provider if pregnancy is planned or suspected or if breastfeeding. Inform patient of National Pregnancy Registry for Antidepressants that monitors pregnancy outcomes in women exposed to antidepressants during pregnancy. Advise pregnant women ≤45 yr of age with a history of psychiatric illness to enroll in the National Pregnancy Registry for Antidepressants by calling (1-866-961-2388) or visiting https://womensmentalhealth.org/research/pregnancyregistry/antidepressants.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇

Time/Action Profile ⬆ ⬇

Contraind./Precautions ⬆ ⬇