Biriperone (also known as Centbutindole) was developed as an antipsychotic drug. It has shown effective antipsychotic activity in schizophrenic patients. Biriperone acts as a dopamine antagonist, and also as a blocker of 5HT(2) receptor. Clinically the drug has passed through phase I, II & III clinical trials successfully, however, the use of this drug was banned.

Moguisteine is a non-narcotic antitussive compound. Moguisteine demonstrated inhibitory effect on rapidly adapting irritant receptors that could account for the antitussigenic effect of this compound. Furthermore, it is possible that ATP-sensitive K(+) channels may be involved in the anti-tussive effect of peripherally acting non-narcotic moguisteine. The drug did not show any toxic effect on the dams and their fetuses, nor did it have any teratogenic effect in either of the tested species. Finally, moguisteine had no adverse effects, either on parturition or on peri-and postnatal survival and/or development of the offspring. It was reported that moguisteine to be effective in reducing cough frequency in chronic cough of bronchitis and COPD. It was recommended for the short-term symptomatic relief of coughing. Preregistration of moguisteine in Italy is discontinued.

Efletirizine is histamine H1 receptor antagonist. Restricted to topical use. It was under investigation in Phase III (in Europe) clinical studies for the treatment of allergic rhinitis and chronic idiopathic urticarial. Research was discontinued in 2005 due to limited clinical efficacy and safety data. Efletirizine also reduced ocular itching.

Stilonium Iodide (also known as MG 624) is a trimethylethanaminium derivative with ganglionic-blocking action. Stilonium Iodide acts as α7-nicotinic receptor antagonist and Stilonium Iodide inhibits transmission between preganglionic and postganglionic neurons in the Autonomic Nervous System. Stilonium Iodide inhibits nicotine-induced proliferation and angiogenesis in human microvascular endothelial cells of the lung. Stilonium Iodide displayed anti-angiogenic activity in Matrigel, rat aortic ring and rat retinal explant assays. Furthermore, MG624 suppressed angiogenesis of NCI-H69 human SCLC tumors in vivo in both the chicken chorioallantoic membrane (CAM) and nude mice model.

Hydroxytamoxifen (Afimoxifene) is an active metabolite of tamoxifen exerting estrogen receptor modulatory function. In addition, hydroxytamoxifen binds to regulates transcriptional activity of the estrogen-related receptor gamma. ASCEND Therapeutics, Inc. was developing TamoGel (4-hydroxytamoxifen gel) for a variety of estrogen-dependent conditions, including breast cancer, cyclic breast pain and gynecomastia.

Bardoxolone methyl, the C-28 methyl ester of 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO) known as CDDO-Me or RTA 402, is one of the derivatives of synthetic triterpenoids. Bardoxolone methyl directly blocks IKKbeta activity and thereby the NF-kappaB pathway by interacting with Cys-179 in the IKKbeta activation loop. Binding of bardoxolone methyl to Kelch-like erythroid cell-derived protein with CNC homology-associated protein 1 (Keap1) disrupts its critical cysteine residues, leading to the release of the nuclear factor erythroid 2-related factor 2 (Nrf2), which hinders its ubiquitination and finally leads to its stabilization and nuclear translocation. In the nucleus, Nrf2 activates the transcription of phase 2 response genes, leading to a coordinated antioxidant and anti-inflammatory response. In addition, it acts as an antagonist of the peroxisome proliferator-activated receptor gamma. Through Keap1/Nrf2 and nuclear factor-κB pathways, this agent can modulate the activities of a number of important proteins that regulate inflammation, redox balance, cell proliferation and programmed cell death. This agent is generally well tolerated, but it may increase adverse cardiovascular events. Presently, it is being further tested for the treatment of patients with chronic kidney disease, cancer, and pulmonary arterial hypertension.

Belaperidone (LU111995) is a recently identified antipsychotic agent with high 5-hydroxytryptamine2 and dopamine D4 receptor affinities as well as D4 versus D2 receptor selectivity. The drug did not produce catalepsy. LU111995 prolongs the Q-T interval to a limited degree and is not arrhythmogenic over the physiological range of cycle lengths. Belaperidone had been in phase II clinical trials for the treatment of schizophrenia. However, the study about this drug candidate was discontinued.

Fenmetozole is an alpha-2 adrenergic receptor antagonist which was developed for the treatment of schizophrenic and/or depressed patients, however never reached the market. It was also shown that the drug may reduce symptoms of minimal brain dysfunction in children and antagonize the effect of barbiturates and ethanol.

Ibipinabant (IBI) is an orally active potent cannabinoid-1 receptor (CB1R) antagonist. This drug was studied for the treatment of obesity and psychotic disorders. However, the development of the drug was discontinued in November 2008. Now, ibipinabant is only used for laboratory research, especially structure-activity relationship studies into novel CB1 antagonists.

Clocinizine is an antihistamine derivative of diphenylmethylpiperazine. Clocinizine is a competitive and reversible H1 receptor antagonist. The drug is marketed in Spain under tradename Senioral in combination with phenylpropanolamine for temporary relief of nasal congestion in colds, rhinitis, and sinusitis.