TeCAs have diverse pharmacology and differ from<unk> s in a number of ways. With the exception of amoxapine, TeCAs do not inhibit the reuptake of serotonin. However, aside from mirtazapine, they do inhibit the reuptake of norepinephrine. TeCAs block the serotonin 5-HT2 receptors similarly to<unk> s. Besides mirtazapine, they also block the α1-adrenergic receptor. Conversely, whereas<unk> s have relatively low affinity for the α2-adrenergic receptor, mianserin and mirtazapine potently antagonize this receptor, and this action is thought to be involved in their antidepressant effects. TeCAs block the histamine H1 receptor similarly to the<unk> s, but tend to be even stronger antihistamines than<unk> s. On the other hand, in contrast to almost all<unk> s, TeCAs have only low affinity for the muscarinic acetylcholine receptors, and for this reason, are associated with few or no anticholinergic side effects. Mianserin and mirtazapine are far less toxic than<unk> s in overdose. Binding profiles The binding profiles of various TeCAs in terms of their affinities (, ) for various receptors and transporters are as follows: + Compound 5-HT1A 5-HT2A 5-HT2B 5-HT2C 5-HT3 5-HT6 5-HT7 α1 α2 D2 H1 H2 Amoxapine 58 16 4,310 0.5 2.0 6.0–50 41 50 2,600 3.6–160 7.9–25 1,000 Maprotiline 5,800 11–12 1,000 51 122 ND 50 90 9,400 350–665 0.79–2.0 776 570 Mianserin 4,000 71 9,400 400–2,600 1.6–20 1.6–55 0.63–6.5 5.8–300 55–81 48–56 34 3.8–73 ≥2,100 0.30–1.7 437 820 Mirtazapine >10,000 ≥4,600 >10,000 ≥3,330 6.3–69 200 8.9–39 7.9 265 316–1,815 18–88 >5,454 0.14–1.6 >10,000 670 Setiptiline >10,000 220 >10,000 24 Values are (). The smaller the value, the more strongly the drug binds to the site. For assay species and references, see the individual drug articles. Most but not all values are for human proteins. The TeCAs act as antagonists or inverse agonists of the receptors and as inhibitors of the transporters.
Tetracyclic antidepressant
Tricyclic antidepressant
Atypical antidepressant
Heterocyclic antidepressant
Second-generation antidepressant
Antipsychotic
Atypical antipsychotic
Antipsychotic ester