Niacin (also known as vitamin B3 and nicotinic acid) is bio converted to nicotinamide which is further converted to nicotinamide adenine dinucleotide (NAD+) and the hydride equivalent (NADH) which are coenzymes necessary for tissue metabolism, lipid metabolism, and glycogenolysis. Niacin (but not nicotinamide) in gram doses reduces LDL-C, Apo B, Lp(a), TG, and TC, and increases HDL-C. The increase in HDL-C is associated with an increase in apolipoprotein A-I (Apo A-I) and a shift in the distribution of HDL subfractions. These shifts include an increase in the HDL2:HDL3 ratio, and an elevation in lipoprotein A-I (Lp A-I, an HDL-C particle containing only Apo A-I). The mechanism by which niacin alters lipid profiles is not completely understood and may involve several actions, including partial inhibition of release of free fatty acids from adipose tissue, and increased lipoprotein lipase activity (which may increase the rate of chylomicron triglyceride removal from plasma). Niacin decreases the rate of hepatic synthesis of VLDL-C and LDL-C, and does not appear to affect fecal excretion of fats, sterols, or bile acids. As an adjunct to diet, the efficacy of niacin and lovastatin in improving lipid profiles (either individually, or in combination with each other, or niacin in combination with other statins) for the treatment of dyslipidemia has been well documented. The effect of combined therapy with niacin and lovastatin on cardiovascular morbidity and mortality has not been determined. In addition, preliminary reports suggest that niacin causes favorable LDL particle size transformations, although the clinical relevance of this effect is not yet clear. April 15, 2016: Based on several large cardiovascular outcome trials including AIM-HIGH, ACCORD, and HPS2-THRIVE, the FDA decided that "scientific evidence no longer supports the conclusion that a drug-induced reduction in triglyceride levels and/or increase in HDL-cholesterol levels in statin-treated patients results in a reduction in the risk of cardiovascular events" Consistent with this conclusion, the FDA has determined that the benefits of niacin ER tablets for coadministration with statins no longer outweigh the risks, and the approval for this indication should be withdrawn.

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.

Traxoprodil (CP-101,606) is a potent, selective N-Methyl-D-aspartate (NMDA) receptor (NR2B subunit) antagonist under development by Pfizer for its potential as a neuroprotectant in head injury and neurodegenerative disease. It is in phase II trials in the US and in phase I in Japan for the potential treatment of head injury, such as, Depressive Disorder, Major and Parkinson's Disease. CP-101,606 does not protect against glutamate-induced neurotoxicity in cultured cerebellar neurons, up to a dose of 10 uM. These results are consistent with CP-101,606 being a potent NMDA antagonist, selective for the type of NMDA receptor associated with the hippocampus. Some further investigation revealed that CP-101,606 was associated with a dose-related dissociation and amnesia. These results support the hypothesis that glutamate antagonists may be useful antidyskinetic agents. However, future studies will have to determine if the benefits of dyskinesia suppression can be achieved without adverse cognitive effects.

Trestolone is a synthetic androgen that inhibits the release of follicle-stimulating hormone and impairs spermatogenesis. Luteinizing hormone is also suppressed, which cuts production of testosterone. The azoospermia and oligospermia are reversible after discontinuation of trestolone. Trestolone has androgenic and anabolic properties and loss of secondary sex characteristics is not seen. Like testosterone, trestolone undergoes enzymatic aromatization to an estrogen. The use of trestolone instead of testosterone for androgen replacement therapy could have health-promoting effects by reducing the occurrence of prostate disease. Trestolone had been in phase II clinical trial for the andropause control. However, this development was discontinued.

Alvameline is a partial agonist of the M1 mAChR that also displays M2/M3 antagonist effects. It readily crosses the blood-brain barrier. It has an effect profile that makes it of interest to test its ability to counteract bladder overactivity in humans. Behaviorally, alvameline has been shown to significantly improve Morris water maze (MWM) performance in both young and ageimpaired rats. It failed to improve cognition in patients with mild to moderate Alzheimer's disease.

Palosuran, also known as ACT-058362, a potent and specific antagonist of the human UT receptor. Urotensin inhibition with palosuran was a promising alternative in pulmonary arterial hypertension. Palosuran inhibits binding to primate UT receptors in cell membranes but demonstrates differential activity in intact cells and vascular tissues. Palosuran improves pancreatic and renal function in diabetic rats. Phase-II clinical trials for diabetic nephropathies and cardiovascular disorders were discontinued.