Indantadol (previously known as CHF-3381) is an oral and noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist and reversible monoamine oxidase-A (MAO-A) inhibitor that is being developed by Vernalis plc, under license from Chiesi Farmaceutici SpA, for the potential treatment of neuropathic pain. In preclinical studies, indantadol exhibited neuroprotective effects after kainate-induced seizures and displayed anticonvulsant and antihyperalgesic activity. Indantadol also caused a dose-dependent decrease in exploratory motility. In a human heat-capsaicin-induced pain model, indantadol at a dose of 500 mg effectively reduced the area of secondary hyperalgesia. The tolerability profile of the drug at single doses up to 600 mg and twice-daily doses up to 400 mg in clinical trials was significantly more favorable than for other NMDA antagonists. Most side effects have been observed to be mild, and include dizziness and asthenia. Indantadol was in phase II clinical trials for the treatment of chronic cough and neuropathic pain. However, these studies had been discontinued.

Terikalant is a benzopyran derivative patented by Rhone-Poulenc Sante as an antiarrhythmic agent. In normal cardiac tissues studied in vitro, Terikalant dose-dependently prolonged the atrial and ventricular action potential but affected neither the upstroke of the action potential nor the diastolic potential. Patch-clamp experiments demonstrated that the prolongation of the action potential induced by Terikalant is due to a specific blockade of the inward rectifier K+ current. In vivo, i.v. administration to anesthetized dogs of low doses of Terikalant consistently induced bradycardia and prolonged the atrial, nodal, and ventricular refractory periods, but did not affect the conduction velocity.

Hydrobentizide is a diuretic.

Spiramide (AMI-193) is a spiperone derivative, a selective 5-HT2A, (Ki = 2 nM) 5-HT1A (Ki = 50 nM), and D2 receptor (Ki = 3 nM) antagonist, with negligible affinity for the 5-HT2C receptor (Ki = 4300 nM). The ability of Spiramide to serve as a functional 5-HT2A antagonist in behavioral studies was demonstrated through studies in which Spiramide blocked the discriminative - stimulus effects of the 5HT2A agonist 1-(2,5-dimethoxy-4-methylphenyl)-2-aminopropane (DOM).

Metacetamol (3-hydroxyacetanilide) is a structural isomer of the widely used drug paracetamol and is being considered as a promising alternative to the latter because of its lower toxicity. 3-hydroxyacetanilide, the positional isomer of paracetamol, does not cause depletion of GSH in vivo or hepatotoxicity even though the extent of covalent binding of the reactive metabolite (in vivo or in vitro) is comparable to that for an equimolar dose of paracetamol. Metacetamol should prove to be a useful tool to aid in the discrimination of hepatic acetaminophen protein adducts that may be critical or noncritical to survival of hepatocytes

Capeserod is benzodioxanoxadiazolone derivative patented by patented by pharmaceutical company Synthelabo S. A. as a novel 5-hydroxytryptamine4 receptor partial agonist with potent cognition-enhancing properties. In cells expressing the 5-HT4(b) and 5-HT4(e) splice variants, Capeserod acted as a partial agonist, stimulating cAMP prodn. with a maximal effect of 40 to 50% of serotonin. However, in the rat esophagus preparation, Capeserod acted as a 5-HT4 antagonist with a pKb of 8.81. In addition, Capeserod potently improved performance in several tests of learning and memory. In the object recognition task, it improved retention at 24 h when administered i.p. or p.o. (0.001-0.1 mg/kg). This effect was antagonized by the 5-HT4 antagonist SDZ 205,557, itself without effect, demonstrating that the promnesic effects of Capeserod are mediated by 5-HT4 agonism. Capeserod also reversed the cognitive deficits of aged rats in the linear maze task and the scopolamine-induced deficit of mice in the water maze task. Furthermore, the combined administration of an inactive dose of Capeserod with the cholinesterase inhibitor rivastigmine resulted in a significant promnesic effect, suggesting a synergistic interaction. Capeserod was devoid of unwanted cardiovascular, gastrointestinal, or central nervous system effects with doses up to more than 100-fold higher than those active in the cognitive tests. These results characterize Capeserod as a novel promnesic agent acting via 5-HT4 receptors, with an excellent preclinical profile.

Nitecapone (3-(3,4-dihydroxy-5-nitrobenzylidine)-2,4- pentanedione, OR-462) is a selective, short-acting catechol-O-methyltransferase (COMT) inhibitor, whose main site of action is in the gastrointestinal tract. Nitecapone displays in vivo activity in peripheral tissues but does not penetrate the blood-brain barrier. The compound increases mechanical and thermal nociception and reduces neuropathic pain in diabetic rats and in a spinal nerve ligation model. Nitecapone has been shown to have a protective effect against ischemia-reperfusion injury in experimental heart transplantation and in Langendorff preparations. Nitecapone added to cardioplegia solution reduces cardiac neutrophil accumulation and transcoronary neutrophil activation during clinical cardiopulmonary bypass. Reflected by better left ventricular stroke volume, nitecapone treatment may be an additional way of reducing the deleterious effects of neutrophil activation during cardiopulmonary bypass. Nitecapone was patented as an antiparkinsonian agent but was never marketed.

Fluazuron (N-[[4-chloro-3-[3-chloro-5-(trifluoromethyl)pyridin-2-yl]oxyphenyl]carbamoyl]-2,6-difluorobenzamide, trade name Acatak) is an insect growth regulator belonging to the class of benzoyl phenyl urea derivatives, a class of chitin synthesis inhibitors. Fluazuron specifically interferes with chitin formation in ticks during engorgement, molt, and hatching. The substance is intended for tick control in beef cattle applied topically as a pour-on for use at single dose levels of 1.5 and 2.5 mg/kg BW with a possible additional treatment after 3 to 6 months.

Nidroxyzone (Furadroxyl) is an antibacterial agent. It was used for the treatment of experimental trypanosomiasis in laboratory animals.