n. a tricyclic antidepressant introduced into clinical use in 1961; with imipramine, it was the first widely used antidepressant agent. Its tertiary amine structure makes it a more potent inhibitor of serotonin and norepinephrine reuptake than secondary amines (thereby increasing the availability of serotonin for neurotransmission). It is actually more pronoradrenergic than serotonergic, and it also has significant antihistamine, anticholinergic, and adrenoreceptor-blocking activity (producing adverse side effects). It is an effective antidepressant, but its side effects and toxicity in overdose have led to a decline in its use in favor of the SSRIs and other agents. Although still used as an antidepressant, amitriptyline is no longer considered first-line medication and is more likely to be employed in low doses for chronic pain management or the prevention of migraine. It is also sold in combination with a
benzodiazepine anxiolytic (as Limbitrol in the United States) or an antipsychotic (as Etrafon or Triavil in the United States). U.S. trade name: Elavil.