Thioridazine (Mellaril or Melleril) is a piperidine typical antipsychotic drug belonging to the phenothiazine drug group and was previously widely used in the treatment of schizophrenia and psychosis. Thioridazine blocks postsynaptic mesolimbic dopaminergic D1 and D2 receptors in the brain; blocks alpha-adrenergic effect depresses the release of hypothalamic and hypophyseal hormones and is believed to depress the reticular activating system thus affecting basal metabolism, body temperature, wakefulness, vasomotor tone, and emesis. Thioridazine primary use in medicine was the treatment of schizophrenia. Thioridazine was also tried with some success as a treatment for various psychiatric symptoms seen in people with dementia, but chronic use of thioridazine and other antipsychotics in people with dementia is not recommended. Thioridazine prolongs the QTc interval in a dose-dependent manner. It produces significantly less extrapyramidal side effects than most first-generation antipsychotics. Its use, along with the use of other typical antipsychotics, has been associated with degenerative retinopathies. It has a higher propensity for causing anticholinergic side effects coupled with a lower propensity for causing extrapyramidal side effects and sedation than chlorpromazine but also has a higher incidence of hypotension and cardiotoxicity. It is also known to possess a relatively high liability for causing orthostatic hypotension compared to other antipsychotics. Similarly to other first-generation antipsychotics, it has a relatively high liability for causing prolactin elevation. It is the moderate risk of causing weight gain.

Glutodine (Cyproheptadine), sold under the brand name Periactin or Peritol, is a first-generation antihistamine with additional antiserotonergic, anticholinergic and local anesthetic properties. Glutodine is a white to slightly yellowish crystalline solid, which is soluble in water, freely soluble in methanol, sparingly soluble in ethanol, soluble in chloroform, and practically insoluble in ether. Cyproheptadine is used to treat allergic reactions (specifically hay fever), Vasomotor rhinitis, Allergic conjunctivitis due to inhalant allergens and foods, uncomplicated allergic skin manifestations of urticaria and angioedema amelioration of allergic reactions to blood or plasma, Cold urticaria, and Dermatographism. Cyproheptadine is used off-label to treat Spasticity Associated With Spinal Cord, Migraine Headache Prophylaxis, Decreased Appetite Secondary to Chronic Disease, Drug-Induced Sexual Dysfunction, Serotonin Syndrome.

Fluphenazine is a trifluoro-methyl phenothiazine derivative intended for the management of schizophrenia and other psychotic disorders. Fluphenazine has not been shown effective in the management of behaviorial complications in patients with mental retardation. Fluphenazine blocks postsynaptic mesolimbic dopaminergic D1 and D2 receptors in the brain; depresses the release of hypothalamic and hypophyseal hormones and is believed to depress the reticular activating system thus affecting basal metabolism, body temperature, wakefulness, vasomotor tone, and emesis.

Methylergometrine (other names include methylergonovine, methylergobasin, methergine, and D-lysergic acid 1-butanolamide) is a synthetic analogue of ergonovine, a psychedelic alkaloid found in ergot, and many species of morning glory. In general, the effects of all the ergot alkaloids appear to results from their actions as partial agonists or antagonists at adrenergic, dopaminergic, and tryptaminergic receptors. The spectrum of effects depends on the agent, dosage, species, tissue, and experimental or physiological conditions. All of the alkaloids of ergot significantly increase the motor activity of the uterus. After small doses contractions are increased in force or frequency, or both, but are followed by a normal degree of relaxation. As the dose is increased, contractions become more forceful and prolonged, resting tonus is markedly increased, and sustained contracture can result. Methylergometrine acts directly on the smooth muscle of the uterus and increases the tone, rate, and amplitude of rhythmic contractions through binding and the resultant antagonism of the dopamine D1 receptor. Thus, it induces a rapid and sustained tetanic uterotonic effect which shortens the third stage of labor and reduces blood loss. Methylergometrine is used for the prevention and control of excessive bleeding following vaginal childbirth.

Dihydroergotamine (DHE) is a semisynthetic, hydrogenated ergot alkaloid, synthesized by reducing an unsaturated bond in ergotamine. Dihydroergotamine was originally envisaged as an antihypertensive agent, but it was later shown to be highly effective in treating migraine. Dihydroergotamine was first used to treat migraine in 1945 by Horton, Peters, and Blumenthal at the Mayo Clinic. In 1986, Raskin and Callaham reconfirmed the effectiveness of DHE for both intermittent and intractable migraine. The use of DHE was reviewed by Scott in 1992. In 1997, a nasal spray version was approved for use in migraine. Dihydroergotamine is indicated for the acute treatment of migraine headaches with or without aura and the acute treatment of cluster headache episodes. Dihydroergotamine binds with high affinity to 5-HT1Dα and 5-HT1Dβ receptors. It also binds with high affinity to serotonin 5-HT1A, 5-HT2A, and 5-HT2C receptors, noradrenaline α2A, α2B and α, receptors, and dopamine D2L and D3 receptors. The therapeutic activity of dihydroergotamine in migraine is generally attributed to the agonist effect at 5-HT1D receptors. Two current theories have been proposed to explain the efficacy of 5-HT1D receptor agonists in migraine. One theory suggests that activation of 5-HT1D receptors located on intracranial blood vessels, including those on arterio-venous anastomoses, leads to vasoconstriction, which correlates with the relief of migraine headache. The alternative hypothesis suggests that activation of 5-HT1D receptors on sensory nerve endings of the trigeminal system results in the inhibition of proinflammatory neuropeptide release.

A sulfide ion is composed of a lone sulfur atom. Its charge is negative two, giving sulfides this formula: S^2-. Sulfide is a strong base, so solutions of sulfide in water are basic, due to hydrolysis. One well-known ionic compound with a sulfide ion is H_2S. The infamous rotten-egg smell often associated with sulfur originates from this compound. Sodium sulfide nonahydrate is used in the formation of surface functionalized cadmium sulfide quantum dots.

Nelotanserin is a potent, selective 5-HT(2A) inverse agonist. Originally called ADP-125, the compound was developed by Arena Pharmaceuticals as a treatment for insomnia, but failed efficacy measures for this indication in Phase 2. In 2015, Axovant Sciences licensed this compound for development, renamed it nelotanserin, and began evaluating it in dementia with Lewy bodies (DLB). Both radioligand binding and functional inositol phosphate accumulation assays suggest that nelotanserin has low nanomolar potency on the 5-HT(2A) receptor with at least 30- and 5000-fold selectivity compared with 5-HT(2C) and 5-HT(2B) receptors, respectively. Nelotanserin dosed orally prevented (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI; 5-HT(2A) agonist)-induced hypolocomotion, increased sleep consolidation, and increased total nonrapid eye movement sleep time and deep sleep, the latter marked by increases in electroencephalogram (EEG) delta power. Nelotanserin has been used in trials studying the treatment of Lewy body dementia, visual hallucinations, dementia with Lewy bodies, and REM sleep behavior disorder.

Tiospirone (TSP) is an atypical antipsychotic drug. Tiaspirone appeared to be a promising antipsychotic agent as it didn`t cause extrapyramidal syndromes. It has 5HT-2 antagonistic properties as well as affinity for D2, 5HT-1a, 5HT-6 and sigma receptors. Tiospirone was in phase III clinical trials for the treatment of attention hyperactivity disorder with Mead Johnson in the USA but its development appears to have been discontinued.

Metitepine, a psychotropic agent was developed as a non-selective antagonist of serotonin, dopamine, and adrenergic receptors. Metitepine has never been marketed.

m-Chlorophenylpiperazine (meta-chlorophenylpiperazine or mCPP) is a psychoactive substance, which is illegal in many countries but can be found on the black market. It induces endocrine, neurological and psychiatric effects. mCPP is a partial agonist at the 5-HT2C receptor but antagonized the 5-HT2B and 5-HT3 receptors. mCPP is also an active metabolite of the drug trazodone, which is used as an effective antidepressant drug with a broad therapeutic spectrum, including anxiolytic efficacy. It is known, that mCPP induces migraine attacks and that the decrease of food intake induced by the mCPP depends on its ability to act as a serotonin agonist is a brain.