![](https://upload.wikimedia.org/wikipedia/commons/thumb/1/14/Dibenzazepine.svg/200px-Dibenzazepine.svg.png)
![](https://upload.wikimedia.org/wikipedia/commons/thumb/d/de/Phenothiazin.svg/200px-Phenothiazin.svg.png)
Tricyclics are cyclic chemical compounds that contain three fused rings of atoms.
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
[edit]- 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]
Gallery
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Antipsychotics | ||||
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Antihistamines | ||||
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Others | ||||
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See also
[edit]References
[edit]- ^ 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.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction