Remeron RD

mirtazapine /mir·taz·a·pine/ (mir″taz-ah-pēn) an antidepressant structurally unrelated to any of the classes of antidepressants.

mirtazapine,

an antidepressant.

indications It is used to treat depression, dysthymic disorder, and bipolar disorder with either depression or agitation.

contraindications Factors that prohibit its use include known hypersensitivity to tricyclic antidepressants, convulsive disorders, and prostatic hypertrophy. Its use is also contraindicated in patients who are in the recovery phase of a myocardial infarction.

adverse effects Life-threatening effects are agranulocytosis, thrombocytopenia, eosinophilia, leukopenia, seizures, paralytic ileus, jaundice, hepatitis, acute renal failure, and hypertension. Other adverse effects include confusion, headache, anxiety, tremors, stimulation, nightmares, extrapyramidal symptoms (in the elderly), increased psychiatric symptoms, nausea, vomiting, cramps, epigastric distress, stomatitis, rash, photosensitivity, palpitations, tinnitus, and mydriasis. Common side effects are dizziness, drowsiness, diarrhea, dry mouth, urinary retention, orthostatic hypotension, electrocardiogram changes, tachycardia, and blurred vision.

mirtazapine [mir″taz-ah-pēn]

an antidepressant that is not structurally related to any of the classes of antidepressants.

mirtazapine

Remeron, Remeron RD (CA), Remeron Soltab, Zispin (UK)

Pharmacologic class: Piperazinoazepine derivative

Therapeutic class: Tetracyclic antidepressant

Pregnancy risk category C

FDA Boxed Warning

• Drug may increase risk of suicidal thinking and behavior in children and adolescents with major depressive disorder and other psychiatric disorders. Risk must be balanced with clinical need, as depression itself increases suicide risk. With patient of any age, observe closely for clinical worsening, suicidality, and unusual behavior changes when therapy begins. Advise family and caregivers to observe patient closely and communicate with prescriber as needed.
• Drug isn't approved for use in pediatric patients.

Action

Potentiates effects of norepinephrine and serotonin by blocking their synaptic reuptake. Also exerts anticholinergic activity by disrupting muscarinic receptors.

Availability

Tablets: 15 mg, 30 mg, 45 mg

Tablets (orally disintegrating): 15 mg, 30 mg, 45 mg

⊘Indications and dosages

➣ Depression

Adults: Initially, 15 mg/day as a single dose at bedtime; may increase dosage q 1 to 2 weeks up to 45 mg/day. For maintenance, 15 to 45 mg/day.

Dosage adjustment

• Renal or hepatic impairment
• Elderly patients

Contraindications

• Hypersensitivity to drug
• MAO inhibitor use within past 14 days

Precautions

Use cautiously in:
• hepatic or renal impairment
• history of seizures, cardiovascular or cerebrovascular disease, or psychiatric illness
• elderly patients
• pregnant or breastfeeding patients
• children (safety not established).

Administration

• Administer orally disintegrating tablet without water. Have patient place it on tongue until it melts. Make sure tablet isn't broken.
• Be aware that drug is usually used in conjunction with psychotherapy.
☞ Don't give within 14 days of MAO inhibitors.

Route	Onset	Peak	Duration
P.O.	1-2 wk	≥6 wk	Unknown

Adverse reactions

CNS: drowsiness, dizziness, abnormal dreams, abnormal thinking, asthenia, tremor, confusion, suicidal behavior or ideation (especially in child or adolescent)

CV: orthostatic hypotension, chest pain

EENT: sinusitis

GI: constipation, dry mouth

GU: urinary frequency, urinary tract infection

Hematologic: agranulocytosis

Musculoskeletal: back pain, myalgia

Respiratory: increased cough, dyspnea

Skin: photosensitivity

Other: flulike symptoms, edema, increased appetite, weight gain, increased thirst

Interactions

Drug-drug. Benzodiazepines, other CNS depressants: additive CNS depression

Drugs metabolized by CYP450 enzyme: altered metabolism of these drugs

MAO inhibitors: hypertension, seizures, death

Drug-diagnostic tests. Alanine aminotransferase, cholesterol, triglycerides: increased levels

Drug-herbs. Chamomile, hops, kava, skullcap, valerian: increased CNS depression

S-adenosylmethionine (SAM-e), St. John's wort: increased risk of serotonergic adverse effects (including serotonin syndrome)

Drug-behaviors. Alcohol use: additive CNS effects

Patient monitoring

• Monitor vital signs, especially for orthostatic hypotension.
• Assess neurologic status.
• Watch for weight gain caused by edema or increased appetite.
• Stay alert for urinary tract infection, sinusitis, and flulike symptoms.
☞ Monitor CBC with white cell differential. Stay alert for agranulocytosis.
☞ Watch for suicidal behavior or ideation (especially in child or adolescent).

Patient teaching

• Advise patient to take with food or milk to reduce GI upset.
• Tell patient he may crush conventional tablets if he can't swallow them whole.
• Instruct patient to take orally disintegrating tablet without water. Tell him to place it on tongue until it melts and to make sure tablet isn't broken.
• Advise patient that therapeutic effects may take 2 to 3 weeks.
☞ Tell patient to immediately report sore throat, fever, mouth sores, or other signs or symptoms of infection.
☞ Instruct patient (or parent) to immediately report suicidal thoughts or actions (especially in child or adolescent).
☞ Caution patient not to discontinue drug abruptly. Dosage must be tapered.
• If drug causes oversedation, tell patient to consult prescriber about taking entire daily dose at bedtime.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• Tell patient to avoid alcohol and to discuss herbal use with prescriber.
• Instruct patient to avoid exposure to excessive sunlight or sun lamps.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.