MSI_000006352

Amitriptyline hydrochloride is a dibenzocycloheptene-derivative tricyclic antidepressant (TCA). TCAs are structurally similar to phenothiazines. They contain a tricyclic ring system with an alkyl amine substituent on the central ring. In non-depressed individuals, amitriptyline does not affect mood or arousal, but may cause sedation. In depressed individuals, amitriptyline exerts a positive effect on mood. TCAs are potent inhibitors of serotonin and norepinephrine reuptake. Tertiary amine TCAs, such as amitriptyline, are more potent inhibitors of serotonin reuptake than secondary amine TCAs, such as nortriptyline. TCAs also down-regulate cerebral cortical β-adrenergic receptors and sensitize post-synaptic serotonergic receptors with chronic use. The antidepressant effects of TCAs are thought to be due to an overall increase in serotonergic neurotransmission. TCAs also block histamine-H₁ receptors, α₁-adrenergic receptors and muscarinic receptors, which accounts for their sedative, hypotensive and anticholinergic effects (e.g. blurred vision, dry mouth, constipation, urinary retention), respectively. See toxicity section below for a complete listing of side effects. Amitriptyline may be used to treat depression, chronic pain (unlabeled use), irritable bowel syndrome (unlabeled use), diabetic neuropathy (unlabeled use), post-traumatic stress disorder (unlabeled use), and for migraine prophylaxis (unlabeled use). N - Nervous system > N06 - Psychoanaleptics > N06A - Antidepressants > N06AA - Non-selective monoamine reuptake inhibitors D018377 - Neurotransmitter Agents > D014179 - Neurotransmitter Uptake Inhibitors > D018759 - Adrenergic Uptake Inhibitors C78272 - Agent Affecting Nervous System > C265 - Antidepressant Agent > C94727 - Tricyclic Antidepressant D002491 - Central Nervous System Agents > D011619 - Psychotropic Drugs > D000928 - Antidepressive Agents D018373 - Peripheral Nervous System Agents > D018689 - Sensory System Agents D018377 - Neurotransmitter Agents > D018663 - Adrenergic Agents D002491 - Central Nervous System Agents > D000700 - Analgesics D049990 - Membrane Transport Modulators