PROTRIPTYLINE HYDROCHLORIDE

PROTRIPTYLINE HYDROCHLORIDE
(proe-trip'te-leen)
Triptil

, Vivactil
Classifications: psychotherapeutic; tricyclic antidepressant;
Therapeutic: antidepressant, tricyclic
Prototype: Imipramine
Pregnancy Category: C

Availability

5 mg, 10 mg tablets

Action

Tricyclic antidepressant (TCA) with more rapid onset of action than imipramine. Has little if any sedative properties characteristic of most other TCAs. It is believed that their most important effect is to enhance the actions of norepinephrine and serotonin by blocking their reuptake at the neuronal membrane.

Therapeutic Effect

TCAs potentiate both norepinephrine and serotonin in CNS by blocking their reuptake by presynaptic neurons. Effective in the treatment of mentally depressed individuals, particularly those who are withdrawn.

Uses

Symptomatic treatment of endogenous depression in patients under close medical supervision. Particularly effective for depression manifested by psychomotor retardation, apathy, and fatigue.

Contraindications

Hypersensitivity to TCAs; concurrent use of MAOIs; during acute recovery phase following MI; QT prolongation, bundle branch block; cardiac conduction defects; suicidal ideation; pregnancy (category C).

Cautious Use

Hepatic, cardiovascular, or kidney dysfunction; diabetes mellitus; hyperthyroidism; history of alcoholism; patients with insomnia; asthma; bipolar disorder; suicidal tendencies; children and adolescents; lactation.

Route & Dosage

Antidepressant
Adult: PO 15–40 mg/d in 3–4 divided doses (max: 60 mg/d)
Adolescent: PO 15 mg/d in divided doses

Administration

Give whole or crush and mix with fluid or food.
Give dosage increases in the morning dose to prevent sleep interference and because this TCA has psychic energizing action.
Give last dose of day no later than midafternoon; insomnia rather than drowsiness is a frequent adverse effect.
Store at 15°–30° C (59°–86° F) in tightly closed container.

Adverse Effects (≥1%)

Body as a Whole: Photosensitivity, edema (general or of face and tongue). GI: Xerostomia, constipation, paralytic ileus. Special Senses: Blurred vision. Urogenital: Urinary retention. CNS: Insomnia, headache, confusion. CV: Change in heat or cold tolerance; orthostatic hypotension, tachycardia.

Interactions

Drug: May decrease some response to antihypertensives; cns depressants, alcohol, hypnotics, barbiturates, sedatives potentiate CNS depression; oral anticoagulants may increase hypoprothrombinemic effects; ethchlorvynol causes transient delirium; levodopa sympathomimetics (e.g., epinephrine, norepinephrine) increases possibility of sympathetic hyperactivity with hypertension and hyperpyrexia; mao inhibitors present possibility of severe reactions—toxic psychosis, cardiovascular instability; methylphenidate increases plasma TCA levels; thyroid drugs 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 (headache, dizziness, sweating, agitation).

Pharmacokinetics

Absorption: Rapidly from GI tract. Peak levels: 24–30 h. Distribution: Crosses placenta; distributed into breast milk. Metabolism: In liver. Elimination: Primarily in urine. Half-Life: 54–98 h.

Nursing Implications

Assessment & Drug Effects

Monitor therapeutic effectiveness. Onset of initial effect characterized by increased activity and energy is fairly rapid, usually within 1 wk after therapy is initiated. Maximum effect may not occur for 2 wk or more.
Monitor adolescents as well as adults for changes in behavior that may indicate suicidality.
Monitor vital signs closely and CV system responses during early therapy, particularly in patients with cardiovascular disorders and older adults receiving daily doses in excess of 20 mg. Withhold drug and inform physician if BP falls more than 20 mm Hg or if there is a sudden increase in pulse rate.
Lab tests: Obtain periodic liver function and blood cell counts in patients receiving large doses for prolonged periods or in combination with other drugs.
Monitor I&O ratio and question patient about bowel regularity during early therapy and when patient is on large doses.
Assess and advise physician as indicated for prominent anticholinergic effects (xerostomia, blurred vision, constipation, paralytic ileus, urinary retention, delayed micturition).
Assess condition of oral membranes frequently; institute symptomatic treatment if necessary. Xerostomia can interfere with appetite, fluid intake, and integrity of tooth surfaces.
Supervise patient closely during early treatment period. Suicide is an inherent risk with any depressed patient and may remain until there is significant improvement.
Bear in mind that the potentiation of TCA effects may increase the danger of overdosage or suicide attempt (especially in patients who use excessive amounts of alcohol).

Patient & Family Education

Consult physician about safe amount of alcohol, if any, that can be taken. Actions of both alcohol and protriptyline are potentiated when used together for up to 2 wk after the TCa is discontinued.
Stop or to reduce smoking; smoking reduces TCAs effectiveness. Apparent treatment failure may be due to the nicotine effect.
Consult physician before taking any OTC medications.
Be aware that effects of barbiturates and other CNS depressants are enhanced by TCAs.
Avoid potentially hazardous activities requiring alertness and skill until response to drug is known.
Avoid exposure to the sun without protecting skin with sunscreen lotion (SPF >12). Photosensitivity reactions may occur.

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

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