Tefludazine (Lu 18-012) is a mixed D2 and 5-HT2 receptor antagonist that was developed as a potential antipsychotic compound. It was shown that tefludazine induced a dose-dependent decrease in both nigra pars compacta (SNC) and ventral tegmental area (VTA) dopamine (DA) activity. The development of the drug was discontinued in Phase I due to toxicological findings in dogs.

Niravoline [RU 49679, RU 51599, niravolin], a novel aqueous diuretic with κ-opioid agonistic action. The drug was originally being developed by Hoechst Marion Roussel. Niravoline is a selective agonist of kappa-opioid receptors having potent aquaretic activity. Niravoline was studied with respect to the treatment of brain oedema, heart failure and liver cirrhosis. Niravoline, administered at moderate doses, safely induced a powerful aquaretic effect in patients with cirrhosis and ascites. Moderate doses of niravoline appeared to be a promising pharmacological tool in the treatment of water retention in patients with cirrhosis. The development of niravoline as an aquaretic for the treatment of cirrhosis with ascites and other hyponatraemic disorders has also been halted.

Moxaprindine is a antiarrhythmic drug for the treatment of ventricular arrhythmias patented by Manufacture de Produits Pharmaceutiques A. Christiaens, S. A. In clinical studies Moxaprindine shows high efficacy in suppressing ventricular arrhythmias occurring before, during and after maximal exercise stress testing. This effect was obtained both in subjects with clinically normal hearts and in a limited number of patients with ischemic heart disease.

Pyrophenindane is pyrrolidylmethyl-substituted arylindan patented by Mead Johnson & Co. as antispasmodic agent. Pyrophenindane have potent activity in the prevention of reserpine-induced ptosis in mice, a test for antidepressant activity.

IRINDALONE is an antihypertensive agent. It is a serotonin receptor antagonist with weak alpha 1-adrenoceptor blocking properties.

Indacrinone is an orally active, indanone-based loop diuretic patented by American pharmaceutical company Merck and Co as mixture of two enantiomers. In healthy volunteers, the racernic mixture of indacrinone exhibited greater natriuretic potency than furosemide, with a slower onset and longer duration of action. Furthermore, single doses of indacrinone decreased serum uric acid concentrations and increased uric acid clearance, while similar doses of furosemide generally had the opposite effects. Differences in the pharmacologic effects of the resolved enantiomers of indacrinone were initially studied in animals and confirmed in a series of studies we conducted in healthy human volunteer. The S( + ) form is a potent uricosuric agent that produces mild natriuresis only at higher doses, while the R( - ) form is a potent loop diuretic with only transient uricosuric effects. The (-) enantiomer and its active metabolite appear to be primarily responsible for the natriuretic effects of the racemic mixture; the ( + ) enantiomer is 20-40 times less potent a natriuretic agent.