Preladenant (SCH-420814) is an adenosine A(2A) receptor antagonist with a high affinity and very high selectivity for adenosine A(2A) receptors, which is being developed by Merck & Co Inc (following its acquisition of Schering-Plough Corp) for the potential treatment of Parkinson's disease. Preladenant is a potent competitive antagonist of the human A2Areceptor (Ki = 1.1 nM) and has >1000-fold selectivity over all other adenosine receptors, making this compound the most selective A2A receptor antagonist reported to date. Preladenant was being researched as a potential treatment for Parkinson's disease. Positive results were reported in Phase II clinical trials in humans, but it did not prove itself to be more effective than a placebo during Phase III trials, and so was discontinued in May 2013.

The novel compounds clamikalant (HMR 1883) or its sodium salt HMR 1098) have been shown to block selectively Kir6.2/SUR1-composed K(ATP) channels. Clamikalant is under development by Aventis Pharma (formerly Hoechst Marion Roussel) for the potential treatment of heart arrest and ventricular arrhythmias. Nevertheless, clamikalant and its sodium salt did not pass the clinical trials

Pituxate is the antitussive and bronchospasmolytic agent.

Quinacainol (also known as PK 10139 or RP 54272) is a quinolinemethanol derivative patented by Pharmindustrie as an antiarrhythmic agent. Quinacainol acts as a sodium channel antagonist and demonstrated both class Ia and Ic antiarrhythmic properties. Quinacainol blocked sodium currents in a concentration-dependent manner and with a potency similar to that of quinidine. Quinacainol produces a slowing of action potential conduction, consistent with a block of sodium channels, and a slight prolongation of action potential duration, consistent with a block of potassium currents.

Tauromustine, a new taurine-based nitrosourea that was developed as an anticancer agent. Tauromustine participated in phase III clinical trial in patients with either anaplastic astrocytoma (AA) or glioblastoma (GBM) not previously treated with chemotherapy. Besides, was studied in phase III in patients with advanced colorectal cancer. Tauromustine also was used in phase II trials for the treatment of malignant glioma. However, further studies were discontinued.

Rogletimide (pyridoglutethimide) is a second-generation nonsteroidal aromatase inhibitor that has been evaluated for use in the treatment of breast cancer. Rogletimide is a structural analog of aminoglutethimide (AG), a nonspecific aromatase inhibitor. Roglemitide is slightly less potent than AG but does not inhibit the cholesterol side-chain cleavage and shows no sedative activity. However, compared to AG, it has sub-optimal aromatase inhibition and oestradiol suppression.

Lobendazole is a metabolite of veterinary drug thiophanate. Lobendazole possesses teratogenic effect.

Pirodavir (R77975) (ethyl 4-[2-(1-[6-methyl-3-pyridazinyl]-4-piperidinyl)ethoxy]benzoate) and its predecessor (R61837) belong to a series of pyridazine analogues developed by the Janssen Research Foundation. Compared to R61837, pirodavir was 500-fold more potent as an antiviral in vitro, inhibiting 80% of 100 rhinovirus serotypes tested at concentration of 0.064 mg/mL or less. Pirodavir acts at an early stage of the viral replication cycle (up to 40 min after infection) and reduces the yield of selected rhinoviruses 1,000- to 100,000-fold in a single round of replication. The mode of action appears to be serotype specific, since pirodavir was able to inhibit the adsorption of human rhinovirus 9 but not that of human rhinovirus 1A. Pirodavir is a novel capsid-binding antipicornavirus agent with potent in vitro activity against both group A and group B rhinovirus serotypes.

Sulnidazole is a nitroimidazole derivative patented by Belgian pharmaceutical company Janssen Pharmaceutica N. V. as an antiprotozoal agent that effective against Trichomonas vaginalis.

Tiotidine is a controversial histamine H2 receptor ligand with negligible activity against H1- and H3- receptors. It was found that tiotidine behaves as an inverse agonist in U-937 cells, diminishing basal cAMP levels. Tiotidine showed two binding sites, one with high affinity and low capacity and the other with low affinity and high capacity. Tiotidine is currently in use as a radioligand in histamine H2-receptor binding studies. Compared to cimetidine, tiotidine appears to be approximately eight times more potent on a molar basis than cimetidine as an inhibitor of acid secretion, and the tiotidine effect is more prolonged. It was developed for the treatment of peptic ulcer.