Protriptyline Hydrochloride

Name: Protriptyline Hydrochloride

Protriptyline Hydrochloride Dosage and Administration

General

Depressive Disorders

  • Allow at least 2 weeks to elapse between discontinuance of therapy with an MAO inhibitor and initiation of protriptyline and vice versa.a c Also allow at least 5 weeks to elapse when switching from fluoxetine.a c

  • Monitor for possible worsening of depression, suicidality, or unusual changes in behavior, especially at the beginning of therapy or during periods of dosage adjustments.101 102 103 a d (See Worsening of Depression and Suicidality Risk under Cautions.)

  • Avoid abrupt discontinuance of therapy in patients receiving protriptyline for prolonged periods.a b To avoid withdrawal reactions, taper dosage gradually.a b (See Withdrawal of Therapy under Cautions.)

Administration

Oral Administration

Administer orally in up to 4 divided doses or as a single daily dose.a b

Dosage

Available as protriptyline hydrochloride; dosage expressed in terms of the salt.a

Individualize dosage carefully according to individual requirements and response.a b c

Pediatric Patients

Depressive Disorders Oral

Adolescents: Lower dosages recommended than for adults.a b Initially, 5 mg 3 times daily.a b Increase dosage gradually if necessary.a b (See Pediatric Use under Cautions.)

After symptoms are controlled, gradually reduce dosage to the lowest level that will maintain relief of symptoms.a b

Adults

Depressive Disorders Oral

Initially, 15–40 mg daily, depending on the severity of the condition being treated.a b Increase dosage gradually up to 60 mg daily if necessary; increases should be made to the morning dose if given in divided doses.a b

After symptoms are controlled, gradually reduce dosage to the lowest level that will maintain relief of symptoms.a b

Prescribing Limits

Adults

Depressive Disorders Oral

Maximum 60 mg daily.a b

Special Populations

Geriatric Patients

Lower dosages recommended for geriatric patients.a b Initially, 5 mg 3 times daily.a b Increase dosage gradually if necessary.a b Carefully monitor for cardiac abnormalities if dosages >20 mg daily are administered.a b

Interactions for Protriptyline Hydrochloride

Drugs Affecting Hepatic Microsomal Enzymes

Inhibitors of CYP2D6: potential pharmacokinetic interaction (increased plasma protriptyline concentrations) with concomitant use; use with caution.a c Consider protriptyline dosage adjustment whenever a CYP2D6 inhibitor is added or discontinued.a c

Specific Drugs

Drug

Interaction

Comments

Alcohol

Potentiates the effects of alcohola c

Increased risks if overdose or suicide attempt occursa

Antiarrhythmics: class 1C (e.g., flecainide, propafenone); quinidine

Potential for decreased protriptyline metabolisma c

Dosage adjustment may be neededa c

Anticholinergic agents

Possible addictive anticholinergic effects; hyperthermia, particularly during hot weather; and paralytic ileusa c

Use with caution; dosage adjustment may be neededa c

Antipsychotics (e.g., phenothiazines)

Potential for decreased protriptyline metabolisma c

Dosage adjustment may be neededa c

Cimetidine

Possible increased plasma protriptyline concentrationsa c

Potential for TCA toxicity, particularly adverse anticholinergic effectsa c

Monitor for TCA toxicity; dosage adjustment may be neededa c

Cisapride

Increased risk of QT interval prolongation and arrhythmiasa c

Concomitant use contraindicateda c

CNS depressants (e.g., analgesics, antihistamines, barbiturates, general anesthetics, opiates)

Potentiates the effects of CNS depressantsa c

Guanethidine and related compounds

Possible antagonism of the antihypertensive effects of guanethidine and related compoundsa c

Levodopa

May interfere with levodopa absorptionc

Monitor levodopa dosage carefullyc

MAO inhibitors

Potentially life-threatening serotonin syndrome a c

Concomitant use contraindicateda c

Allow at least 2 weeks to elapse when switching to or from these drugsa c

Methylphenidate

Potential for decreased metabolism and increased therapeutic efficacy and toxicity of TCAsc

SSRIs (e.g., citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, sertraline)

Potential for decreased protriptyline metabolism and increased plasma concentrationsa c

Use with caution; dosage adjustment may be neededa c

Allow at least 5 weeks to elapse when switching from fluoxetinea c

Sympathomimetic agents (e.g., amphetamines, epinephrine, isoproterenol, norepinephrine, phenylephrine)

Increased vasopressor, cardiac effectsa c

Use with caution; dosage adjustment may be requireda c

Thyroid agents

Possible cardiac arrhythmiasa c

Use with caution a c

Tramadol

Possible increased risk of seizuresa c

Protriptyline Hydrochloride Pharmacokinetics

Absorption

Bioavailability

Completely absorbed from GI tract; bioavailability averages from 75–90%.a b c k l m

Peak plasma concentrations occur within 8–12 hours after oral administration.a l

Onset

May have a more rapid onset of antidepressant action compared with amitriptyline or imipramine.a Initial clinical effect may occur within 1 week; maximum antidepressant effects may not be evident for ≥2 weeks.a b

Distribution

Extent

Widely distributed in the body.a c l m

Possibly distributed into milk.e

Plasma Protein Binding

Highly bound to plasma proteins.c k l m

Elimination

Metabolism

Metabolized via the same pathways as are other TCAs.b m 10–25% of oral dose undergoes first pass metabolism.l m

Poor metabolizers of CYP2D6 metabolize the drug more slowly than normal metabolizers.a c

Elimination Route

50% of a dose is excreted in urine as metabolites within approximately 16 days.a b Very small amounts excreted in feces via biliary elimination.a b

Half-life

54–124 hours.k l m

Actions

  • Mechanism of action in the management of depression unknown but may involve inhibition of reuptake of norepinephrine and serotonin.a c

  • Exhibits anticholinergic and antiadrenergic activity.a c m

  • Does not inhibit MAO.a Does not possess sedative and tranquilizing activity.a l

  • Associated with more frequent anticholinergic and cardiovascular effects than SSRIs and more frequent CNS stimulation and cardiovascular effects than other TCAs.a c

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

Protriptyline Hydrochloride

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Oral

Tablets, film-coated

5 mg

Vivactil (with polyethylene glycol and propylene glycol)

Odyssey

10 mg

Vivactil (with polyethylene glycol and propylene glycol)

Odyssey
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