Amitriptyline hydrochloride

Indications & Dose:

Abdominal pain or discomfort (in patients who have not responded to laxatives, loperamide, or antispasmodics)

•  BY MOUTH

Adult: Initially 5–10 mg daily, to be taken at night; increased in steps of 10 mg at least every 2 weeks as required; maximum 30 mg per day

Depressive illness (not recommended— increased risk of fatality in overdose)

•   BY MOUTH

Adult: Initially 75 mg daily in divided doses, alternatively initially 75 mg once daily, dose to be taken at bedtime, increased if necessary to 150– 200 mg daily, dose to be increased gradually

Elderly: Initially 30–75 mg daily in divided doses, alternatively initially 30–75 mg once daily, dose to be taken at bedtime, increased if necessary to 150–200 mg daily, dose to be increased gradually

Neuropathic pain

•   BY MOUTH

Adult: Initially 10 mg once daily, increased if necessary to 75 mg once daily, dose to be taken at night, dose to be increased gradually, higher doses to be given on specialist advice continued’

Migraine prophylaxis

•  BY MOUTH

Adult: Initially 10 mg once daily, then increased if necessary to 50–75 mg once daily (max. per dose 150 mg), dose to be taken at night

Adolescent/Geriatric: • PO 30 mg/day in divided daces, may be increased to 150 mg/day

Elderly: Depression; initially 10mg daily, increasing gradually under closed supervision, over 10 days 30-75mg daily

Obsessional & Phobic states, initially 10mg daily increasing gradually according to severity.

Children:7-10 years, 10-20mg, 11-16  years 2550mg at night; max period of treatment (including gradual withdrawal) 3 months full physical examination before further course.

Children: Less than 7 years not recommended. 

Contraindications:

Acute recovery phase of MI, concurrent use of MAOIs.

Side Effects:

Cautions:

Precautions:

Suicidal patients, convulsive disorders, prostatic hypertrophy, psychiatric disease, severe depression, increased intraacular pressure, narrow-angle glaucoma, urinary retention, cardiac disease (2nd or 3rd degree heart block or sick sinus syndrome, hepatic disease/renal disease, hyperthyroidism, electroshock therapy, elective surgery, elderly, abrupt discontinuation

Interaction:

Drugs

Altretamine: orthostatic hypotension

Amphetamines: Theoretical increase in effect of amphetamines, clinical evidence lacking

Anticholinergics: Excessive anticholinergic effects

Barbiturates: Reduced serum concentrations of cyclic antidepressants

Bethanidine: Reduced antihypertensive effect of bethanidine

Carbamazepine: Reduced antidepressant serum concentrations

Cimetidine (other H2 blockers less likely to have effect): Inhibition of TCA metabolism

Clonidine: Reduced antihypertensive response to clonidine; enhanced hypertensive response with abrupt clonidine withdrawal

Epinephrine, norepinephrine: Enhanced pressor response

Ethanol: Additive impairment of motor skills; abstinent alcoholics may eliminate cyclic antidepressants more rapidly than nonalcoholics

Fluoxetine, paroxetine: Marked increases in cyclic antidepressant plasma concentrations

Guanabenz, guanfacine, debrisoquin: Inhibition of antihypertensive effect

Guanethidine, guanadrel: Inhibited antihypertensive response to guanethidine

Hypoglycemics: Enhanced hypoglemic effects Isoproterenol: Increased cardiac arrhythmias

Lithium: Increased risk of neurotoxicity

MAOIs: Excessive sympathetic response, mania, or hyperpyrexia possible

Moclobemide: Potential association with fatal or non-fatal serotonin syndrome

Neuroleptics: Increased therapeutic and toxic effects of both drugs 4D

Norepinephrine: Markedly enhanced pressor response to norepinephrine

Phenylephrine: Enhanced pressor response

Propoxyphene: Enhanced effect of cyclic antidepreants

Quinidine: Increased cyclic antidepressant serum concentrations

Rifampin: Possible decreased TCA levels

Ritonavir, indinavir: Increased TCA levels 

Warnings:

Adverse Effects:

Lactations:

Excreted into breast milk; effect on nursing infant unknown but may be of concern 

Special Precautions:

Counselling:

Side Effects Or Adverse Reactions:

CNS: Anxiety, confusion (especially in elderly), dizziness, drowsiness, extra-pyramidal symptoms (elderly), fatigue, headache, increased psychiatric symptoms, insomnia, memory impairment, nervousness, nightmares, panic, stimulation, tremors, weakness

CV: Dysrhythmias, hypertension, orthostatic hypotension, palpitations, syncope, tachycardia

EENT: Blurred vision, mydriasis, nasal congestion, ophthalmoplegia, tinnitus

GI: Constipation, cramps, diarrhea, dry mouth,epigastric distress, hepatitis, increased appetite, jaundice, nausea, paralytic ileus, stomatitis, vomiting, weight gain

GU: Urinary retention

HEME: Agranulocytosis, easinophilia, leukopenia, thrombocytopenia

SKIN: Photosensitivity, pruritus, rash, sweating, urticaria 

Patient And Carer Advice: