Taranabant is a highly selective cannabinoid-1 (CB1) receptor inverse agonist developed by Merck & Co for the treatment of obesity. The Phase III taranabant study involved about 2,400 patients and was to be conducted for two years. In March 2008, after completion of 52 weeks of the study, Merck reported positive results of the drug in conjunction with diet and exercise in obese patients. The patients experienced double the amount of weight loss by taking 2mg of taranabant when compared to the patients treated with placebo. However, in October 2008, the company discontinued the Phase III programme and clinical development of taranabant because of its side effects. The drug showed gastrointestinal and psychiatric side effects such as increased anxiety, depression and irritability. Merck had previously planned to file for regulatory approval with the US Food and Drug Administration in 2008, but subsequently withdrew it.

Meobentine is an antiarrhythmic agent. Meobentine significantly increases the electrical ventricular fibrillation threshold in animal models. Meobentine may prevent induction of ventricular tachycardia or fibrillation, or reduce frequency of complex ventricular ectopy in selected patients refractory to other antiarrhythmic agents, but the response rate is relatively low.

Nerisopam [EGIS 6775, GYKI 52322] is a novel 2,3-benzodiazepine derivative with both anxiolytic and antipsychotic activity in animal studies. Nerisopam induces rapid, intense expression of Fos-like immunoreactivity in the rostral, dorsomedial and lateral parts of the striatum in the rat. The striatal neurons are the primary targets of this anxiolytic and antipsychotic drug in the central nervous system. Nerisopam does not bind to the central dopamine receptors, but it shows affinity to the 5-HT1 receptors (IC50 = 7.1 x 10(-6) mol/l) and inhibits brain cAMP-phosphodiesterase (IC50 = 2.4 x 10(-5) mol/l). Nerisopam development for the treatment of anxiety disorder and schizophrenia were discontinued in phase 1.

Tifluadom is an opioid benzodiazepine with potent analgesic activity. Studies using antagonists for κ-, δ-, and μ-opiate receptors in guinea pig myenteric plexus-longitudinal muscle preparation and mouse and rabbit vasa deferentia showed that Tifluadom is an opioid analgesic with a preference for opiate κ-receptors. In rat brain homogenates, tifluadom displaced kappa-antagonist naloxone from its binding sites with an IC50 of 12nM but had no effect on flunitrazepam binding. Tifluadom produced a dose-related diuresis in normally hydrated rats and the diuretic effect was antagonized by naloxone and blocked by morphine administration.

Pimetremide is a spasmolytic agent.

Propenzolate is a pyridine derivative patented by National Research Development Corp. as an anticholinergic agent. Propenzolate is effective antidotes to the cholinesterase-inhibiting action of various organophosphorus compounds. In clinical trials, Propenzolate has an activity that decreases to some extent the secretion of hydrochloric acid and the volume of gastric juice. Adverse effects, including nausea, vomiting, weakness, and drowsiness, as well as xerostomia and cycloplegia, are observed in a high percentage of patients receiving 0.5 to 1.0 mg. every 12 hours.

Podilfen is the vasodilator. It was used as an antihypertensive agent.