- Tricyclic Antidepressant
- Tablets USP 10, 25, 50 and 75 mg
- Depressive Illness
- Depressive Illness of Psychotic or Endogenous Nature
- Neurotic Depression
- Anxiety Component of Depression
- Inhibits the membrane pump mechanism responsible for the re-uptake of transmitter amines
- Drug has anticholinergic properties, so it produces EKG changes and quinidine-like effects on the heart
- peak serum time: 4 hours
- Orally administered drugs is readily absorbed and rapidly metabolized.
- Metabolized by hepatic CYP2C19, CYP3A4
- Metabolite: Nortriptyline
- Half-life: 9-27 hours
- Major in the urine, with some excretion in the feces.
- Outpatient Adults:
- Initial dose: 25 mg 3 times a day.
- Max dose: 150 mg/day.
- Increases should made preferably in the late afternoon or bedtime doses.
- Severely ill or hospitalized patients:
- Initial dose: 100 mg a day
- Max dose: 200 mg a day (Small number of hospitalized patients may need 300 mg a day)
- Adolescent and Elderly Patients:
- Lower dosages are recommended.
- The dose should be administered in divided doses or as a single dose in the evening or at bedtime.
- When satisfactory improvement has been reached, dosage should be reduced to the lowest amount that will maintain relief of symptoms.
- Usual maintenance dose: 50 to 100 mg/day in divided doses
- In suitable patients, the total daily dosage may be given in a single dose, preferably at bedtime.
- Guanethidine or similarly acting compounds
- Anticholinergic or sympathomimetic drugs (including epinephrine combined with local anesthetics)
- Alcohol, barbiturates and other CNS depressants
- Anticholinergic agents or with neuroleptic drugs
- drowsiness, fatigue, activation of latent schizophrenia, disorientation, confusional states, hallucinations, delusions, hypomanic reactions, disturbed concentration, nightmares, insomnia, restlessness, agitation, excitement, jitteriness, anxiety, giddiness.
- epileptiform seizures, coma, dizziness, tremors, numbness, tingling, parasthesias of the extremities, peripheral neuropathy, headache, ataxia, alteration in EEG patterns, extrapyramidal symptoms including abnormal involuntary movements and tardive dyskinesia, dysarthria, tinnitus, incoordination, and slurred speech.
- Urinary retention, dilatation of the urinary tract, constipation, paralytic ileus, especially in the elderly, hyperpyrexia, dry mouth, blurred vision, disturbance of accommodation, increased intraocular pressure, precipitation of latent glaucoma, aggravation of existing glaucoma, and mydriasis.
- quinidine-like effect and other non-specific ECG changes and changes in AV conduction, prolonged conduction time, asystole, hypotension, syncope, hypertension, palpitation, arrhythmias, heart block, ventricular tachycardia, fibrillation, myocardial infarction, stroke, unexpected death in patients with cardiovascular disorders.
- Bone marrow depression, including agranulocytosis, leukopenia, eosinophilia, purpura, thrombocytopenia.
- Skin rash, urticaria, photosensitization, edema of the face and tongue, itching. Gastrointestinal: nausea, epigastric distress, heartburn, vomiting, hepatitis (including altered liver function and jaundice), anorexia, stomatitis, peculiar taste, diarrhea, parotid swelling, black tongue may occur.
- Testicular swelling, gynecomastia and impotence in the male, breast enlargement and galactorrhea in the female, increased or decreased libido, elevation and lowering of blood sugar levels, syndrome of inappropriate ADH (antidiuretic hormone) secretion.
- Weakness, increased perspiration, edema, urinary frequency, alopecia, increased appetite, weight gain, weight loss.
Withdrawal Symptoms (following abrupt cessation):
- Nausea, headache, and malaise, irritability, restlessness, and dream and sleep disturbance. These symptoms are not indicative of addiction.
- MAO inhibitors
- Myocardial infarction (during the acute recovery phase following MI)
- Acute congestive heart failure
Pregnancy and Breastfeeding
- Pregnancy: Category C
- Lactation: Not recommended in nursing mothers
- Caution in patients with a history of:
- Impaired Liver Function,
- Hepatic Damage,
- Blood Dyscrasias,
- cardiovascular disease (myocardial infarction & congestive heart failure)
- Atropine-like action: caution in patients with a history of:
- urinary retention,
- narrow-angle glaucoma
- Increased intra-ocular pressure.
- Fatal Dysrhythmia:
- Occurring as late as 56 hours after amitriptyline overdose.
- Cardiovascular disorders and Stroke:
- Caution in concurrent usage >>> Patients should be watched closely.
- TCA drugs produce arrhythmias, sinus tachycardia, and prolongation of the conduction time.
- Electroshock Therapy:
- Concurrent administration increase the hazards of therapy >>> treatment should be limited to the specific patients
- Hyperthyroid Patients:
- Close supervision is required
- Occupational Hazards:
- Impair mental and/or physical abilities required for performance of hazardous tasks >>> caution in operating machinery or driving a motor vehicle.
- Not recommended for patients under 12 years of age.
- Treatment of depressive component of schizophrenia:
- Activation or aggravation of existing psychotic manifestation may occur.
- Seriously depressed patients:
- Should be carefully supervised.
- The possibility of suicide remains during treatment.
- Patients should not have access to large quantities of drug during treatment.
- Elective Surgery:
- Discontinue the drug several days before surgery
- MAO Inhibitors:
- Concomitant usage with MAO inhibitors result in: Hyper-pyretic crises, severe convulsions, and deaths
- Minimum of 14 days elapse is needed.
- Myocardial Infarction & Congestive Heart Failure:
- Not recommended for use during the acute recovery phase following myocardial infarction and in the presence of acute congestive heart failure.
- EEG & Sleep Patterns:
- It also lowers the convulsive threshold and causes alterations in EEG and sleep patterns.
- Guanethidine or Similarly Acting Compounds:
- Amitriptyline block the anti-hypertensive action of Guanethidine.
- Anticholinergic or sympathomimetic drugs (including epinephrine combined with local anesthetics):
- Concomitant usage needs close supervision and adjustment of dosage.
- Paralytic ileus: appropriate measures should be taken if constipation occurs.
- Reduce hepatic metabolism of tricyclic antidepressants.
- Concomitant usage result in transient delirium: Caution if patients is receiving large doses of Ethchlorvynol.
- Alcohol, barbiturates and other CNS depressants:
- Amitriptyline enhances the response to alcohol and the effects of barbiturates and CNS depressants.
- Caution Delirium has been reported with concurrent administration of amitriptyline and disulfiram.
- Anticholinergic agents or with neuroleptic drugs:
- Hyperpyrexia has been reported when tricyclic antidepressants are administered with anticholinergic agents or with neuroleptic drugs.
- Over dosage:
- Symptoms: temporary confusion, disturbed concentration, transient visual hallucinations, drowsiness, hypothermia, tachycardia, arrhythmic abnormalities, such as bundle branch block, ECG evidence of impaired conduction, congestive heart failure, disorders of ocular motility, convulsions, severe hypotension, stupor, coma, polyradiculoneuropathy and constipation.
- Treatment is symptomatic and supportive.
- Patients who may have ingested an over dosage of amitriptyline, particularly children, should be hospitalized and kept under close surveillance.
This document is prepared by the “Mental Health for All” team. This document is provided for information purposes only and does not necessarily represent endorsement by or an official position of the Essentials of Medicine. Advice on the treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient or is familiar with that patient’s medical history.