| Class | Serotonergic antidepressant |
|---|---|
| Chemistry |
Triazolopyridine derivative |
| Routes of administration |
Oral only |
| Absorption |
Rapidly and completely absorbed; 63-91% oral bioavailability |
| Solubility |
pKa 7.09; slightly water-soluble |
| Distribution |
VOD = 0.8L/kg; 95% protein-bound |
| Metabolism |
Hepatic metabolism into tow main metabolites, oxotriazolepyridinpropionic acid (TPA) and mCPP, of which mCPP is more active as an inhibitor of SERT than trazodone itself. |
| Elimination |
All metabolites are renally eliminated |
| Time course of action |
Elimination half-life is about 7 hours |
| Target receptor |
Serotonin reuptake transport protein (SCL6A4, or SERT), as well as a direct antaginist effect at the 5-HT2 receptor |
| Mechanism of action |
Specifically, the direct antaginist effect at the 5-HT2 receptor results in increased presynaptic noradrenaline release. That receptor is a presynaptic autoregulatory receptor which normally downregulates noradrenaline release as part of a negative feedback loop. |
| Clinical effects |
Sedation, diarrhoea, loss or gain of weight, vertigo; risk of serotonin syndrome with overdose |
| Literature reference |
Georgotas et al (1982) |
| CICM details of understanding | Not specifically listed in the CICM syllabus |
| Mentioned around Deranged Physiology | |
| Related SAQs |