Tricyclics are cyclic chemical compounds that contain three fused rings of atoms.

Dibenzazepine
Phenothiazine

Many compounds have a tricyclic structure, but in pharmacology, the term has traditionally been reserved to describe heterocyclic drugs. They include antidepressants, antipsychotics, anticonvulsants, and antihistamines (as antiallergens, anti-motion sickness drugs, antipruritics, and hypnotics/sedatives) of the dibenzazepine, dibenzocycloheptene, dibenzothiazepine, dibenzothiepin, phenothiazine, and thioxanthene chemical classes, and others.

History

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  • Promethazine and other first generation antihistamines with a tricyclic structure were discovered in the 1940s.
  • Chlorpromazine, derived from promethazine originally as a sedative, was found to have neuroleptic properties in the early 1950s, and was the first typical antipsychotic.
  • Imipramine, originally investigated as an antipsychotic, was discovered in the early 1950s, and was the first tricyclic antidepressant.
  • Carbamazepine was discovered in 1953, and was subsequently introduced as an anticonvulsant in 1965.
  • Clozapine, a derivative of imipramine, was synthesized in 1958 and entered the European market in 1972 under the name Leponex.
  • Antidepressants with a tetracyclic structure such as mianserin and maprotiline were first developed in the 1970s as tetracyclic antidepressants.
  • Loratadine was introduced as a non-sedating second generation antihistamine in the 1990s.[1]
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Antidepressants
 

Imipramine

 

Amitriptyline

 

Iprindole

 

Tianeptine

 

Doxepin

Antipsychotics
 

Chlorpromazine

 

Thioridazine

 

Chlorprothixene

 

Loxapine

 

Clozapine

Antihistamines
 

Promethazine

 

Cyproheptadine

 

Latrepirdine

 

Loratadine

 

Rupatadine

Others
 

Carbamazepine

 

Carvedilol

 

Cyclobenzaprine

 

Pizotifen

See also

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References

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  1. ^ Kay, G. G.; Harris, A. G. (1999). "Loratadine: a non-sedating antihistamine. Review of its effects on cognition, psychomotor performance, mood and sedation". Clinical and Experimental Allergy. 29 Suppl 3: 147–150. doi:10.1046/j.1365-2222.1999.0290s3147.x. PMID 10444229.