tricyclic

American  

[trahy-sahy-klik, -sik-lik] / traɪˈsaɪ klɪk, -ˈsɪk lɪk /

adjective

1. pertaining to or embodying three cycles.

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noun

1. Also called tricyclic antidepressant.  Pharmacology. any of a group of pharmacologically active substances, as imipramine, that share a common three-ring structure, used to treat depression and cocaine abuse.

tricyclic British  

/ traɪˈsaɪklɪk /

adjective

1. (of a chemical compound) containing three rings in the molecular structure

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noun

1. an antidepressant drug having a tricyclic molecular structure

tricyclic Scientific  

/ trī-sī′klĭk,-sĭk′lĭk /

1. Relating to a chemical compound having three closed rings. Anthracene is a tricyclic hydrocarbon.

2. Relating to a class of drugs used to treat depression and having a tricyclic chemical structure consisting of two benzene rings fused to opposite sides of a seven-member ring. The seven-member ring consists of six carbon atoms and one nitrogen atom. Tricyclic antidepressants enhance the activity of monoamine neurotransmitters in the brain by inhibiting their reuptake by the cells that secrete them.

3. Composed of or arranged in three distinct whorls, as the petals of a flower.

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Etymology

Origin of tricyclic

First recorded in 1890–95; tri- + cyclic

Example Sentences

Schildkraut had initially planned to become a psychoanalyst but completed training just as tricyclic antidepressants came into use.

From Salon • May 23, 2025

First there were tricyclic antidepressants, then there were SSRIs like Prozac and SNRIs like Cymbalta, drugs that target neurotransmitters such as serotonin and norepinephrine.

From Los Angeles Times • Oct. 2, 2022

For example, cancer patients with pain as a result of nerve damage caused by chemotherapy might first be treated with paracetamol and a tricyclic antidepressant.

From BBC • Jul. 21, 2018

One example is tricyclic antidepressants, a class of drugs that do not have FDA approval as treatment for nerve-related pain yet are considered by doctors to be the first choice of drugs for that purpose.

From Washington Post • Oct. 6, 2017

I try anti-inflammatories, steroids, muscle relaxants, antihistamines, beta blockers, calcium-channel blockers, SSRIs, tricyclic antidepressants, antipsychotics, anticonvulsants, and a medication prescribed to slow the onset of Alzheimer’s.

From The Guardian • Nov. 17, 2016