Generic
Amitriptyline Hydrochloride
Pharmacology
Amitriptyline is a tricyclic antidepressant. It has marked anticholinergic and sedative properties. It prevents the reuptake of noradrenaline and serotonin at the nerve ending. Amitriptyline hydrochloride is rapidly absorbed from the Gl tract. Peak plasma concentrations occur within 2-12 hours. Amitriptyline is excreted in the urine, mainly in the form of its metabolites.
Dosage Administration
The mechanism of action of this drug is not fully elucidated. It is suggested that amitriptyline inhibits the membrane pump mechanism responsible for the re-uptake of transmitter amines, such as norepinephrine and serotonin, thereby increasing their concentration at the synaptic clefts of the brain. These amines are important in regulating mood. The monoamine hypothesis in depression, one of the oldest hypotheses, postulates that deficiencies of serotonin (5-HT) and/or norepinephrine (NE) neurotransmission in the brain lead to depressive effects. This drug counteracts these mechanisms, and this may be the mechanism of amitriptyline in improving depressive symptoms. Whether its analgesic effects are related to its mood-altering activities or attributable to a different, less obvious pharmacological action (or a combination of both) is unknown.
Side Effects
TCA enhances the sedative effect of alcohol and opioid analgesics. When TCA is used with Moxifloxacin or Terfenadine, it increases the risk of ventricular arrhythmias. Disulfirum and Cimetidine inhibit the metabolism of Amitriptyline. When TCA is used with diuretics, it enhances the risk of postural hypotension.
Pregnancy And Lactation
Amitriptyline is contraindicated in myocardial infarction, arrythmias, particularly heart block of any degree, mania and severe liver disease. Initially, sedation may affect the ability to drive or operate machinery.
Therapeutic
It should be used with caution in patients with a history of epilepsy, glaucoma, urinary retention, cardiac disease, diabetes, pregnancy, hepatic impairment, thyroid disease, increased intra-ocular pressure and psychoses (may aggravate mania).
Storage Conditions
Tricyclic Anti-depressant
Over The Counter Products
