Azaprocin is an opioid analgesic that has never been marketed.

Icofungipen is a generic name of the compound, previously known as BAY 10-8888 or PLD-118. Icofungipen, a cyclic beta-amino acid was developed by PLIVA, under license from Bayer, for the potential oral treatment of fungal infection. The drug exerts its antifungal activity by inhibition of isoleucyl-tRNA synthetase activity and consequently disrupting protein biosynthesis. Phase II trials with an oral formulation of icofungipen were underway in Europe for Candida infection and for the treatment of vulvovaginal candidiasis in the USA, but these studies have been discontinued. In human toxicity studies, suppression of spermatogenesis in male volunteers was observed as a possible off-target adverse event.

Triampyzine is an anticholinergic, antisecretory agent.

Succinobucol (also known as AGI-1067) is a probucol derivative patented by American pharmaceutical company Atherogenics, Inc as vascular protectant with antioxidant, anti-inflammatory and antiplatelet activities. In vitro, succinobucol inhibits the TNF-α induced expression of VCAM-1 and MCP-1 with little effect on intercellular adhesion molecule (ICAM)-1. In addition, succinobucol inhibits lipopolysaccharide (LPS)-induced expression of tissue factor in human monocytic cells and endothelial cells, an effect thought to be mediated independently from the nuclear factor κB pathway. Preclinical studies have shown reduced total cholesterol and low-density lipoprotein cholesterol concentrations, increased high-density lipoprotein cholesterol concentrations, decreased levels of inflammatory mediators, and reduced atheroma area with Succinobucol treatment in animal models. Unfortunately, in clinical trials, Succinobucol failed to demonstrate a strong cardioprotective effect. Undesired metabolic effects including high-density lipoprotein cholesterol-lowering have been consistently reported, and diarrhea appears to be an expected adverse effect.

Levosemotiadil is an S-enantiomer of semotiadil. It is an antiarrhythmic drug with sodium and calcium channel blocking action, as well as potassium blocking activity. Levosemotiadil is bound strongly and enantioselectively to human serum albumin and human alpha1-acid glycoprotein. Since levosemotiadil is hydrophobic basic drug, it is likely that this drug is also bound to lipoprotein in human plasma. Levosemotiadil might be effective in prevention of lethal arrhythmias. It was shown, that levosemotiadil prevented ventricular fibrillation in 64% of the high-risk animals. Heart rate responses to myocardial ischemia and to graded doses of isoproterenol were blunted by the high dose of levosemotiadil. Levosemotiadil had been in phase II clinical trials by Santen Pharmaceutical for the treatment of arrhythmias. However, this study was discontinued.

Semotiadil (also known as sesamodil or SD 3211) is a (+)-(R)-stereoisomer, the corresponding (−)-(S)-stereoisomer is called levosemotiadil. Semotiadil, a benzothiazine derivative was developed as a novel Ca2+ channel blocker with antiplatelet activity. Experiments on rodents have revealed that the drug had an advantage in the treatment of angina with regard to long-lasting action and selectivity for coronary artery and myocardium. In addition, semotiadil improved survival of rats with monocrotaline-induced pulmonary hypertension: comparison with diltiazem. Semotiadil was studied in phase II clinical trials for the treatment of angina pectoris and hypertension in Europe, and in Japan for the treatment of arrhythmias. However, the further development of semotiadil has now been discontinued.

Sumanirole is a novel dopamine agonist with high affinity and efficacy at D2 dopamine receptors and has a substantial degree of selectivity for the D2 receptor over other dopamine receptor subtypes. It had been in clinical trials for the treatment of Parkinson’s disease and restless leg syndrome but these studies were terminated for the efficacy reason.