TRIMIPRAMINE MALEATE

TRIMIPRAMINE MALEATE (tri-mip'ra-meen) Surmontil Classifications: psychotherapeutic; tricyclic antidepressant; Therapeutic:tricyclic antidepressant Prototype: Imipramine Pregnancy Category: C

Availability

25 mg, 50 mg, 100 mg capsules

Action

Tricyclic antidepressant (TCA) with moderate anticholinergic and strong sedative effects; useful in depression associated with anxiety and sleep disturbances. Recent studies suggest strong, active H₂-receptor antagonism is a characteristic of TCAs.

Therapeutic Effect

More effective in alleviation of endogenous depression than other depressive states.

Uses

Treatment of major depression.

Unlabeled Uses

Peptic ulcer disease.

Contraindications

Hypersensitivy to tricyclic antidepressants; prostatic hypertrophy; during recovery period after MI; AV block; bundle-branch block; ileus; MAOI therapy; QT prolongation; pregnancy (category C).

Cautious Use

Schizophrenia, electroshock therapy, psychosis; Parkinson's disease; seizure disorders; suicidal tendency; cardiovascular, liver, thyroid, kidney disease; lactation.

Route & Dosage

Depression Adult: PO 75–100 mg/d in divided doses, may increase gradually up to 300 mg/d if needed PO Maintenance Dose Usually 50–150 mg/d Geriatric: PO 25 mg h.s., may increase q3d (max: 100 mg/d)

Administration

Oral

• Give with food to decrease gastric distress.
• Store in tightly closed container at 15°–30° C (59°–86° F) unless otherwise specified.

Adverse Effects (≥1%)

CNS: Seizures, tremor, confusion, sedation. Special Senses: Blurred vision. CV: Tachycardia, orthostatic hypotension, hypertension. GI: Xerostomia, constipation, paralytic ileus. Urogenital: Urinary retention. Skin: Photosensitivity, sweating.

Interactions

Drug: May decrease some antihypertensive response to antihypertensives; cns depressants, alcohol, hypnotics, barbiturates, sedatives potentiate CNS depression; may increase hypoprothrombinemic effect of oral anticoagulants; ethchlorvynol may cause transient delirium; with levodopa, sympathomimetics (e.g., epinephrine, norepinephrine), possibility of sympathetic hyperactivity with hypertension and hyperpyrexia; with mao inhibitors, possibility of severe reactions, toxic psychosis, cardiovascular instability; methylphenidate increases plasma TCA levels; thyroid agents may increase possibility of arrhythmias; cimetidine may increase plasma TCA levels. Herbal: Ginkgo may decrease seizure threshold; St. John's wort may cause serotonin syndrome.

Pharmacokinetics

Absorption: Rapidly absorbed from GI tract. Peak: 2 h. Metabolism: In liver. Elimination: In urine and feces. Half-Life: 9.1 h.

Nursing Implications

Assessment & Drug Effects

• Assess vital signs (BP and pulse rate) during adjustment period of tricyclic antidepressant (TCA) therapy. If BP falls more than 20 mm Hg or if there is a sudden increase in pulse rate, withhold medication and notify physician.
• Orthostatic hypotension may be sufficiently severe to require protective assistance when patient is ambulating. Instruct patient to change position from recumbency to standing slowly and in stages.
• Monitor for changes in behavior that may indicate increased incidence of suicidality.
• Report signs of liver dysfunction: Yellow skin and sclerae, light-colored stools, pruritus, abdominal discomfort.
• Report fine tremors, a distressing extrapyramidal adverse effect, to physician.
• Monitor bowel elimination pattern and I&O ratio. Severe constipation and urinary retention are potential problems, especially in older adults. Advise increased fluid intake to at least 1500 mL/d (if allowed).
• Monitor patient carefully during initial drug therapy when therapeutic "lag period" may foster noncompliance.
• Inspect oral membranes daily with high-dose therapy. Urge outpatient to report symptoms of stomatitis or xerostomia.
• Regulate environmental temperature and patient's clothing carefully; drug may cause intolerance to heat or cold.
• Excessive alcohol may potentiate TCA effects and increase the danger of overdosage or suicide attempt.

Patient & Family Education

• Be aware that your ability to perform tasks requiring alertness and skill may be impaired.
• Do not use OTC drugs unless approved by physician.
• Understand that the actions of both alcohol and trimipramine are increased when used together during therapy and for up to 2 wk after the TCA is discontinued. Consult physician about safe amounts of alcohol, if any, that can be taken.
• Be aware that the effects of barbiturates and other CNS depressants may also be enhanced by trimipramine.
• Expect that therapeutic response will be delayed because TCAs have a "lag period" of 2–4 wk. Increased dosage does not shorten period but rather increases incidence of adverse reactions. Keep physician advised and do not interrupt therapy.

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Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug