Adverse effects
• CNS: Disturbed concentration, sedation and anticholinergic (atropine-like) effects, confusion (especially in elderly), hallucinations, disorientation, decreased memory, feelings of unreality, delusions, anxiety, nervousness, restlessness, agitation, panic, insomnia, nightmares, hypomania, mania, exacerbation of psychosis, drowsiness, weakness, fatigue, headache, numbness, tingling, paresthesias of extremities, incoordination, motor hyperactivity, akathisia, ataxia, tremors, peripheral neuropathy, extrapyramidal symptoms, seizures, speech blockage, dysarthria, tinnitus, altered EEG
• CV: Orthostatic hypotension, hypertension, syncope, tachycardia, palpitations, MI, arrhythmias, heart block, precipitation of CHF, CVA
• Endocrine: Elevated or depressed blood sugar, elevated prolactin levels, inappropriate ADH secretion
• GI: Dry mouth, constipation, paralytic ileus, nausea, vomiting, anorexia, epigastric distress, diarrhea, flatulence, dysphagia, peculiar taste, increased salivation, stomatitis, glossitis, parotid swelling, abdominal cramps, black tongue, hepatitis, jaundice (rare), elevated transaminase, altered alkaline phosphatase
• GU: Urinary retention, delayed micturition, dilation of the urinary tract, gynecomastia, testicular swelling; breast enlargement, menstrual irregularity and galactorrhea; increased or decreased libido; impotence
• Hematologic: Bone marrow depression, including agranulocytosis; eosinophilia, purpura, thrombocytopenia, leukopenia
• Hypersensitivity: Rash, pruritus, vasculitis, petechiae, photosensitization, edema (generalized, face, tongue), drug fever
• Withdrawal: Symptoms on abrupt discontinuation of prolonged therapy: nausea, headache, vertigo, nightmares, malaise
• Other: Nasal congestion, excessive appetite, weight change; sweating, alopecia, lacrimation, hyperthermia, flushing, chills
Interactions
Drug-drug
• Increased TCA levels and pharmacologic (especially anticholinergic) effects with cimetidine, fluoxetine
• Increased TCA levels with methylphenidate, phenothiazines, hormonal contraceptives, disulfiram
• Hyperpyretic crises, severe convulsions, hypertensive episodes and deaths with MAOIs, furazolidone
• Increased antidepressant response and cardiac arrhythmias with thyroid medication
• Increased or decreased effects with estrogens
• Delirium with disulfiram
• Sympathetic hyperactivity, sinus tachycardia, hypertension, agitation with levodopa
• Increased biotransformation of TCAs in patients who smoke cigarettes
• Increased sympathomimetic (especially beta-adrenergic) effects of direct-acting sympathomimetic drugs (norepinephrine, epinephrine)
• Increased anticholinergic effects of anticholinergic drugs (including anticholinergic antiparkisonians)
• Increased response (especially CNS depression) to barbiturates
• Decreased antihypertensive effect of guanethidine, clonidine, other antihypertensives
• Decreased effects of indirect-acting sympathomimetic drugs (ephedrine)
Nursing considerations
Assessment
• History: Hypersensitivity to any tricyclic drug; concomitant therapy with an MAOI; recent MI; myelography within previous 24 hr or scheduled within 48 hr; lactation; EST; preexisting CV disorders; angle-closure glaucoma, increased IOP, urinary retention, ureteral or urethral spasm; seizure disorders; hyperthyroidism; impaired hepatic, renal function; psychiatric patients; manic-depressive patients; elective surgery
• Physical: Weight; T; skin color, lesions; orientation, affect, reflexes, vision and hearing; P, BP, orthostatic BP, perfusion; bowel sounds, normal output, liver evaluation; urine flow, normal output; usual sexual function, frequency of menses, breast and scrotal exam; liver function tests, urinalysis, CBC, ECG
Interventions
• Restrict drug access for depressed and potentially suicidal patients.
• Give IM only when oral therapy is impossible.
• Do not administer IV.
• Administer major portion of dose at bedtime if drowsiness, severe anticholinergic effects occur (note that the elderly may not tolerate single daily dose therapy).
• Reduce dosage if minor side effects develop; discontinue if serious side effects occur.
• Arrange for CBC if patient develops fever, sore throat, or other sign of infection.
Teaching points
• Take drug exactly as prescribed; do not stop abruptly or without consulting health care provider.
• Avoid using alcohol, other sleep-inducing drugs, OTC drugs.
• Avoid prolonged exposure to sunlight or sunlamps; use a sunscreen or protective garments.
• You may experience these side effects: Headache, dizziness, drowsiness, weakness, blurred vision (reversible; if severe, avoid driving and tasks requiring alertness while these persist); nausea, vomiting, loss of appetite, dry mouth (eat frequent small meals; use frequent mouth care and suck on sugarless candies); nightmares, inability to concentrate, confusion; changes in sexual function.
• Report dry mouth, difficulty in urination, excessive sedation.