Generic Name
Amitriptyline hydrochloride
Amitriptyline hydrochloride
Therapeutic Class: Tricyclic Anti-depressant
Pharmacology:
Amitriptyline HCl is an antidepressant with sedative effects. Its mechanism of action in man isn't known. it's not an MAO inhibitor and it doesn't act primarily by stimulation of the central systema nervosum.
Amitriptyline inhibits the membrane pump mechanism liable for the uptake of norepinephrine and serotonin in adrenergic and serotonergic neurons. Pharmacologically, this action may potentiate or prolong neuronal activity since reuptake of those biogenic amines is vital physiologically in terminating transmitting activity. This interference with reuptake of norepinephrine and/or serotonin is believed by some to underlie the antidepressant activity of Amitriptyline.
Indications:
Amitriptyline is indicated for depressive illness, particularly with anxiety and nocturnal enuresis in children.
Dosage & Administration:
Depression:
- Adults: Initially 50-70 mg each day in divided dose or as one dose in the dark at bed time.
- Elderly and adolescents: 25-50 mg daily in divided doses or as single dose at bed time. Dose are often increased gradually as necessary to a maximum of 150-200 mg. Usual maintenance dose is 50-100 mg daily.
Nocturnal enuresis:
- 6-10 years: 10-20 mg at bed time.
- 11-16 years: 25-50 mg at bed time for up to three months and gradually withdrawn.
Interaction:
Monoamine oxidase inhibitors can potentiate the consequences of Amitriptyline.
Anticholinergic agents: Amitriptylin shouldn't tend with symptomatic agents like adrenaline, epinephrine, isoprenaline, noradrenaline.
CNS depressant: Amitriptyline may enhance the response to alcohol, barbiturates.
Cemitidine: Cemitidine is reported to scale back hepatic metabolism of certain tricyclic antidepressants.
Contraindications:
Amitriptyline is contraindicated in myocardial infarct ; arrythmias, particularly heartblock of any degree; mania; severe disease . Initially sedation may effect the power to drive or operate machinery. It should be used with caution in patients with a history of epilepsy, glaucoma, retentiveness , prostatic hypertrophy, constipation, cardiac disease, diabetes, pregnancy, hepatic impairment, thyroid disease, increased intraoccular pressure, psychoses (may aggravate mania).
Side Effects:
- Cardiovascular reactions: Hypotension, syncope, orthostatic hypotension , hypertension, tachycardia, palpitations, myocardial infarction, arrythmias, and Adams-Stokes syndrome stroke.
- CNS and neuromuscular: Confusional states, disturbed concentration disorientation, delusions, and hallucinations.
- Anticholinergic: xerostomia , blurred vision, mydriasis, increased intraoccular pressure, hyperplasia.
- Allergic: rash , urticaria, and photosensitization.
- Haematological: Bone-marrow depression including agranulocytosis, leukopenia, eosinophilia, and thrombocytopenia.
- Gastrointestinal: Nausea, epigastric distress, vomiting anorexia, diarrhoea.
- Endocrine: Testicular swelling, gynaecomastia; breast enlargement, galactorrhoea.
- Other reaction: Dizziness, weakness, fatigue, headache, weight loss
Pregnancy & Lactation:
Pregnancy Category C. Amitriptyline isn't recommended during pregnancy, especially during the primary and trimester because the security of Amitriptyline has not been established yet.
Amitriptyline is detectable in breast milk. due to the intense adverse reactions in infants from Amitriptyline, a choice should be made whether to continue nursing or discontinue the drug
Precautions & Warnings:
Schizophrenic patients may develop increased symptoms of psychosis; patients with paranoid symptomatology may have an exaggeration of such symptoms. Depressed patients, particularly those with known manic-depressive illness, may experience a shift to mania or hypomania. In these circumstances the dose of Amitriptyline could also be reduced or a serious tranquilizer like perphenazine could also be administered concurrently.
The possibility of suicide in depressed patients remains until significant remission occurs. Potentially suicidal patients shouldn't have access to large quantities of this drug. Prescriptions should be written for the littlest amount feasible.
Concurrent administration of amitriptyline and electroconvulsive therapy may increase the hazards related to such therapy. Such treatment should be limited to patients for whom it's essential.
When possible, the drug should be discontinued several days before elective surgery. Both elevation and lowering of blood glucose levels are reported. amitriptyline should be used with caution in patients with impaired liver function.
Storage:
Keep containers well closed and stored below 25˚ C, shielded from light.