Cyproheptadine – blocks 5-HT_2A, H1 and is a mild anticholinergic

Methysergide is a 5-HT_2A antagonist and nonselective 5-HT₁ receptor blocker

Quetiapine blocks 5-HT_2A, 5-HT_1A, dopamine receptors D₁ and D₂, histamine receptor H1, and A1 adrenoreceptors.

Ketanserin Antihypertensive. Blocks 5-HT_2A, 5-HT_2C and Alpha 1 (A1) adrenoreceptors.

Risperidone antipsychotic

Antidepressant: Mirtazapine

Nausea prevention: Ondansetron

IBS treatment: Alosetron, Cilansetron

Carbinoxamine: Cyproheptadine, Hydroxyzine, Methdilazine, Pizotifen, Promethazine, Pizotifen (5-HT_2C antagonist, H1 blocker and anticholinergic useful for migraine), Oxatomide, Oxetorone (also used in the treatment of migrane), Ketotifen

Others:

Azapirones such as buspirone, gepirone, and tandospirone are 5-HT_1A receptor partial agonists marketed primarily as anxiolytics, but also as antidepressants.

The antidepressants vilazodone and vortioxetine are 5-HT_1A receptor partial agonists.

Flibanserin, a drug used for female sexual dysfunction, is a 5-HT_1A receptor partial agonist.

Many atypical antipsychotics, such as aripiprazole, asenapine, clozapine, lurasidone, quetiapine, and ziprasidone, are 5-HT_1A receptor partial agonists, and this action is thought to contribute to their beneficial effects on negative symptoms in schizophrenia.

Triptans such as sumatriptan, rizatriptan, and naratriptan are 5-HT_1B receptor agonists that are used to abort migraine and cluster headache attacks. The ergoline antimigraine agent ergotamine also acts on this receptor.

Serenics such as batoprazine, eltoprazine, and fluprazine are agonists of the 5-HT_1B receptor and other serotonin receptors, and have been found to produce antiaggressive effects in animals, but have not been marketed.

In addition to being 5-HT_1B agonists, triptans (i.e. sumatriptan, almotriptan, zolmitriptan, naratriptan, eletriptan, frovatriptan and rizatriptan) are also agonists at the 5-HT_1D receptor, which contributes to their antimigraine effect caused by vasoconstriction of blood vessels in the brain. The same is true for ergotamine.

The triptan eletriptan is an agonist of the 5-HT_1E receptor. BRL-54443 is a selective 5-HT_1E and 5-HT_1F receptor agonist

Triptans such as eletriptan, naratriptan, and sumatriptan are agonists of the 5-HT_1F receptor.

Serotonergic psychedelics like psilocybin, LSD, and mescaline act as 5-HT_2A receptor agonists.

Agonists of the 5-HT_2B receptor are implicated in the development of cardiac fibrosis.^[13] Fenfluramine, pergolide, and cabergoline have been withdrawn from some markets for this reason.^[14] Many serotonergic psychedelics, such as LSD and psilocin, have been shown to activate this receptor directly.^[15] MDMA has been reported to be both a potent direct agonist^[13] and have an indirect effect by increasing plasma serotonin levels.^[16]

Lorcaserin is an appetite suppressant and anti-obesity drug which acts as a selective 5-HT_2C receptor agonist. meta-Chlorophenylpiperazine (mCPP) is a 5-HT_2C-preferring serotonin receptor agonist that induces anxiety and depression and can cause panic attacks in susceptible individuals.

2-Methyl-5-hydroxytryptamine (2-methylserotonin) and quipazine are moderately selective agonists of the 5-HT₃ receptor that are used in scientific research.

Agonists of this receptor are known to induce nausea and vomiting, and are not used medically.

Cisapride and tegaserod are 5-HT₄ receptor partial agonists that were used to treat disorders of gastrointestinal motility.

Prucalopride is a highly selective 5-HT₄ receptor agonist that can be used to treat certain disorders of gastrointestinal motility.

Other 5-HT₄ receptor agonists have shown potential to be nootropic and antidepressant drugs, but have not been marketed for such indications.

Valerenic acid, a constituent of valerian root, has been found to act as a 5-HT_5A receptor agonist, and this action could be involved in the sleep-promoting effects of valerian.