Oxarbazole was developed as an antiasthmatic agent that inhibited the only bronchoconstriction induced by immune complexes. This drug has never been marketed.

Niravoline [RU 49679, RU 51599, niravolin], a novel aqueous diuretic with κ-opioid agonistic action. The drug was originally being developed by Hoechst Marion Roussel. Niravoline is a selective agonist of kappa-opioid receptors having potent aquaretic activity. Niravoline was studied with respect to the treatment of brain oedema, heart failure and liver cirrhosis. Niravoline, administered at moderate doses, safely induced a powerful aquaretic effect in patients with cirrhosis and ascites. Moderate doses of niravoline appeared to be a promising pharmacological tool in the treatment of water retention in patients with cirrhosis. The development of niravoline as an aquaretic for the treatment of cirrhosis with ascites and other hyponatraemic disorders has also been halted.

Dexverapamil (R-verapamil) is an enantiomer of verapamil. R-isomer behaved as an inhibitor of multidrug-resistant protein MRP1 (involved in the cancer cell multidrug resistance phenotype). It was developed by Knoll (BASF Pharma) as a chemosensitiser and/or modulator of multidrug resistance for use in combination with cancer chemotherapy. Dexverapamil was undergoing phase II clinical studies in France, Italy, Spain, United Kingdom and the US in patients with various cancers. It was also undergoing phase I clinical trials in Japan where it was licensed to Mitsui and Mitsui Toatsu Chemicals. However, development was discontinued. Dexverapamil (R-verapamil) has been developing by AGI therapeutics for the treatment of Irritable bowel syndrome however development was discontinued.

Amenamevir is an antiviral agent discovered by Astellas Pharma Inc. and is considered to exert anantiviral effect by inhibiting the activity of the helicase-primase complex, which is involved in DNA replication of herpes virus. It is a helicase-primase inhibitor against herpes simplex virus 1 (HSV-1), HSV-2, and varicella zoster virus. Amenamevir inhibited the in vitro replication of HSV-1 with a mean 50% effective concentration (EC(50)) of 14 ng/ml. Amenamevir was approved in Japan for the treatment of Herpes zoster.

Cirazoline is an agonist of alpha1A adrenergic receptor, a partial agonist of alpha1B and alpha1D receptors, and an antagonist of alpha2 adrenergic receptors. Cirazoline was used to study the biologic function of adrenergic receptors. Injection of cirazoline into to the paravenricular hypothalamic nucleus of rats suppressed food and water intake. Cirazoline caused a large renal vasopressor response in rats. Systemic administration of cirazoline impaired spatial working memory in monkeys.

Burapitant (SSR-240,600) is a drug developed by Sanofi-Aventis which was one of the first compounds developed that acts as a potent and selective antagonist for the NK1 receptor. Burapitant inhibited the binding of radioactive substance P to tachykinin NK1 receptors in human lymphoblastic IM9 cells, human astrocytoma U373MG cells, and human brain cortex. It also showed a subnanomolar affinity for guinea pig NK1 receptors but was less potent on rat and gerbil NK1 receptors. Burapitant inhibited [Sar(9),Met(O2)(11)]substance P-induced inositol monophosphate formation in human astrocytoma U373MG cells. Burapitant (0.1-10 mg/kg i.p. or p.o.) antagonized the excitatory effect of i.c.v. infusion of [Sar(9),Met(O2)(11)]substance P (SP) on the release of acetylcholine in the striatum of anesthetized and awake guinea pigs. This antagonistic action was still observed after repeated administration of Burapitant (5 days, 10 mg/kg p.o., once a day). Burapitant (10 mg/kg i.p.) inhibited the phosphorylation of the cAMP response element-binding protein in various brain regions induced by i.c.v. administration of [Sar9,Met(O2)(11)]SP. While burapitant itself did not proceed beyond early clinical trials and was never developed for clinical use in humans, promising animal results from this and related compounds have led to a number of novel drugs from this class that has now been introduced into medical use.

Talaglumetad (also known as LY-544344) is a bicyclohexane derivative patented by Eli Lilly and Company as modulators of metabotropic glutamate receptor. Talaglumetad acts as a prodrug of Eglumegad, a selective agonist of metabotropic glutamate receptors (mGluR2/3) and metabolized to release active compound by both human jejunal homogenates and rat liver homogenates. In experiments on mice, Talaglumetad was found to be as effective as diazepam for treating anxiety symptoms in several standard tests, but without producing any of the negative side effects of diazepam such as sedation and memory impairment.

Codoxime is a synthetic derivative of an opiate dihydrocodeinone. It differs from dihydrocodeinone by the substitution of a carboxymethyl oxime for the ketonic oxygen at carbon 6 of the dihydrocodeinone molecule. Codoxime has been proposed as an antitussive with prolonged duration of action. In a clinical trial conducted on prisoner volunteers in 1966, it was found that codoxime has a capacity to produce physical dependence of the morphine type.