Prinoxodan (also known as RGW2938) is a benzodiazinone derivative patented by Rorer International (Overseas), Inc as inotropic agents, useful in treating congestive heart failure. Prinoxodan administered intravenously (i.v.) to anesthetized dogs increased contractile force while decreasing arterial pressure and total peripheral resistance (TPR) in a dose-related manner. A single oral dose of Prinoxodan administered to conscious chronically instrumented dogs produced a marked and sustained increase in contractility 15-240 min after treatment.

Prizidilol (also known as SKF 92657) is arylpyridazinylhydrazine derivative patented by Smith Kline and French Laboratories Ltd. as an antihypertensive agent. In clinical trials, Supine and standing blood pressure measured 24--27 h after drug intake was reduced Slight but significant decreases in heart rate were seen after moderate doses of prizidilol. A more pronounced blood pressure reduction was noticed 2--7 h after drug administration. Prizidilol was well tolerated, although dizziness and tiredness were reported by four patients and edema by two.

Premazepam is a pyrrolodiazepine derivative patented by Gruppi Lepetit S.p.A. as a muscle relaxant. Premazepam is a partial agonist of benzodiazepine receptors and was shown in 1984 to possess both anxiolytic and sedative properties in humans. Premazepam had a different EEG profile from diazepam, producing slower and less fast wave activity. In the single dose study, its effects were similar to diazepam for sedative action and most of the psychological tests, with a tendency towards greater psychomotor impairment. In the repeated dose study, however, premazepam caused less sedation and also tended to produce less psychomotor impairment.

Pipoxizine is the antihistamine agent and antiserotonin agent. It was used as antiarrhythmic and bronchodilator.

Pifenate is an analgesic agent.

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.

Evenamide (NW-3509) is a blocker of voltage-gated sodium channels. Evenamide modulates sustained repetitive firing, without inducing impairment of normal neuronal excitability. It normalizes glutamate release induced by aberrant sodium channel activity. The potential benefits of the compound have been demonstrated in numerous preclinical models predictive of efficacy in psychiatric diseases, including models of psychosis such as amphetamine-induced hyperactivity, sensorimotor gating and information processing deficits (pre-pulse inhibition impairment induced by different stimuli), mania and depression. Evenamide is being evaluated in a Phase II trial as add-on treatment to 5HT2/D2 blocking antipsychotics in schizophrenic patients.