Rimcazole is a carbazole derivative that acts as a sigma receptor antagonist and studied as potential antipsychotic agent for the treatment of acute schizophrenic patients. In open-clinical trials Rimcazole (BW 234U) appears to be effective in acute schizophrenic patients. However, subsequent clinical trials demonstrated that rimcazole lacked efficacy in schizophrenic patients and it is now primarily used as an experimental tool. In addition to its actions as  receptor antagonist, rimcazole also has high affinity for dopamine transporters, and inrecent years it has served as a lead compound for the development of novel dopamine transporter ligands.

Mavatrep (JNJ-39439335) is a TRPV1 antagonist. It exerts analgesic potential. Mavatrep demonstrated sustained pharmacodynamic effects (heat pain perception, heat pain latency, capsaicin-induced flare), and an efficacy signal in participants with osteoarthritis

Elinogrel, previously known as PRT060128 or PRT128, is a direct-acting, reversible P2Y12 inhibitor for both intravenous and oral administration. Elinogrel has been tested in 2 phase II studies for the treatment of acute coronary syndrome, myocardial infarction and prevention of secondary thrombotic events. Elinogrel therapy was associated with an increased incidence of dyspnea and incidence of elevated liver transaminases. The development of the drug was terminated in January 2012 by Novartis.

Ronactolol is an aminopropanol derivative and a beta-adrenergic receptor antagonist. This compound has been withdrawn from development.

Efaroxan (RX 821037) is a potent and selective alpha(2)-adrenoceptor antagonist. Additionally, Efaroxan is a selective antagonist at the imidazoline I1 receptor. Efaroxan promotes insulin secretion, in the absence of exogenous agonists, by a mechanism that involves inhibition of ATP-regulated K+ channels. Efaroxan was in clinical trials for the treatment of diabetes mellitus however its development has been discontinued.

Altanserin is a potent and selective 5-HT2A receptor antagonist. Serotonin (5-HT) system functioning have been proposed for a variety of psychiatric disorders, but a direct method quantitatively assessing 5-HT release capacity in the living human brain is still lacking. It was suggested that the combination of a dexfenfluramine-induced 5-HT release and subsequent assessment of 5-HT(2A) receptor availability with [(18)F]altanserin by positron emission tomography (PET) was suitable to measure cortical 5-HT release capacity in the human brain. Besides human neuroimaging studies altanserin has also been used in the study of rats.

Darodipine is a calcium channel blocking drug, developed by Sandoz in the early 1980s. It potently and selectively antagonizes calcium-induced contraction, decreases the rate of spontaneously beating guinea-pig and rabbit atria. In open-chest dogs, darodipine increased coronary flow and cardiac output, lowered blood pressure, and tended to decrease heart rate while the myocardial contractile force was unchanged. Administration of darodipine led to a significant reduction in mortality and in the severity of neurological symptoms in various types of experimental brain ischemia. Clinical trials demonstrated efficacy for the treatment of stable angina pectoris. In the pilot trial, darodipine was found to be safe but not effective in patients with acute ischemic cerebral infarction.

Etintidine is a potent competitive antagonist of histamine H2-receptors. It has a low level of antiandrogenic activity. Etintidine was being investigated in the treatment of peptic ulcer, however, its development has been discontinued.

Cilengitide is a cyclized Arg-Gly-Glu (RGD)-containing pentapeptide that selectively blocks activation of the αvβ3 and αvβ5 integrins. Its precursor was first synthesized in 1995 as c(RGDfV), and later modified by the incorporation of N-methyl Val c(RGDfMetV), generating the current form of the drug. Cilengitide displays subnanomolar antagonistic activity for αvβ3 and αvβ5, and is the first integrin antagonist evaluated in clinical phase I and II trials for treatment of glioblastoma and several other tumor types. Cilengitide-induced glioma cell death and inhibition of blood vessel formation may use different molecular mechanisms, including regulation of tumor hypoxia and activation of apoptotic pathways. Cilengitide inhibits cell signaling through FAK-Src-Akt and Erk mediated pathways in endothelial and tumor cells and attenuates the effect of VEGF stimulation on growth factor signaling. Cilengitide has shown encouraging activity in patients with glioblastoma as single agent, and in association with standard RT and temozolomide.

Eliprodil, also known as SL 82-0715, is a non-competitive NMDA glutamate receptor antagonist, which targets the polyamine modulatory site and is selective for NR2B subunit-containing receptors. Eliprodil was in phase III clinical trial for the treatment of stroke or traumatic brain injury. However, these investigations were failed. One reason suggested for failure was that eliprodil had blocked the synaptic transmission mediated by NMDA receptors, hindering neuronal survival. In addition, eliprodil has been studied in phase II clinical trials for the treatment of Parkinson's disease.