Tripitramine
Selective M2 receptor antagonist
From Wikipedia, the free encyclopedia
Tripitramine, or tripitamine, is an antimuscarinic drug which was never marketed.[1][2][3][4]
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| Other names | Tripitamine |
| Drug class | Muscarinic acetylcholine receptor antagonist; Selective muscarinic acetylcholine M2 receptor antagonist |
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| Formula | C64H77N13O6 |
| Molar mass | 1124.405 g·mol−1 |
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Pharmacology
The drug is a selective antagonist of the muscarinic acetylcholine M2 receptor.[1][2][3][5][6] Its affinities (Ki) for the muscarinic acetylcholine receptors are 0.27 nM for the M2 receptor, 1.58 nM for the M1 receptor (5.9-fold less than for M2), 6.41 nM for the M4 receptor (24-fold less than for M2), 33.87 nM for the M5 receptor (125-fold less than for M2), and 38.25 nM for the M3 receptor (142-fold less than for M2).[2][5] Tripitramine has been found to be cardioselective and to increase heart rate in animals.[1][7]
Chemistry
Structurally, it consists of three pirenzepine- or AQ-RA 741-like tricyclic (more specifically pyridobenzodiazepine) moieties bound together by a long amine-containing hydrocarbon chain similar to the one found within methoctramine (a modestly M2-selective antimuscarinic agent).[1][8][4] Related compounds with analogous structural designs include dipitramine, spirotramine, caproctamine, and benextramine, among others.[1]
History
Tripitramine was first described in the scientific literature by 1993.[4] It was developed in efforts to discover more highly selective M2 receptor antagonists than methoctramine.[1][4]