Azasetron is an antiemetic drug. It acts as serotonin 3 receptor antagonist. It is currently used to prevent nausea and vomiting caused by cancer chemotherapy (including cisplatin chemotherapy). Also it was demonstrated that azasetron has potent antimitogenic and apoptotic effect on cancer cell line. It was preclinically tested to treat cocaine abuse.

Alprenolol is a beta adrenoreceptor blocking agent and 5HT1A antagonist, developed by AstraZeneca and now available as generic drug. It is used for treatment of hypertension, angina pectoris due to coronary atherosclerosis and acute myocardial infarction.

Dipyrone, also known as Metamizole (INN), is an ampyrone sulfonate analgesic, antispasmodic and antipyretic. It was withdrawn from US market in 1977 on the basis of reports of agranulocytosis. Depyrone is still used to treat severe and diffucult for relieving pains of different origin; headache, tooth-ache, pains in the joints, muscles, following traumas and operations, gall and kidney colics, neurites, neuralgias, traumatic cerebrasthenia; inflammation of upper respiratory ways of microbial or virus origin; chorea; febrile states. Mechanism of action of dipyrone is complex. It is believed that dipyrone exerts its action by inhibiting COX-3, and activates opioid and cannabioid systems either itself, or by products of its metabolic degradation.

Ramosetron (INN) is a serotonin 5-HT3 receptor antagonist for the treatment of nausea, vomiting. And "diarrhea-predominant irritable bowel syndrome in males" (IBS-D). Ramosetron is licensed for use in India, Japan (Iribo) and selected Southeast Asian countries. In animal studies, ramosetron reduced defecation induced by corticotrophin-releasing hormone and had inhibitory effects on colonic nociception. In two randomized controlled studies including 957 patients with IBS-D, ramosetron increased monthly responder rates of patient-reported global assessment of IBS symptom relief compared with placebo. Ramosetron was also as effective as mebeverine in male patients with IBS-D. In a recent randomized controlled trial with 343 male patients with IBS-D, ramosetron has proved effective in improving stool consistency, relieving abdominal pain/discomfort, and improving health-related quality of life. Regarding safety, ramosetron is associated with a lower incidence of constipation compared with other 5-HT3 receptor antagonists and has not been associated with ischemic colitis.

Flupirtine is a triaminopyridine derivative having a chemical structure - 2-amino-3-ethoxy-carbonylamino-6-4-fluoro-benzylamino-pyridine. The basic molecule used for synthesis of flupirtine was 2, 6-dichoro 3-nitropyridine. It was first synthesized in 1980s in Germany and was marketed by Degussa Pharma. Flupirtine is a centrally acting, non-opioid analgesic that is available in a number of European countries for the treatment of a variety of pain states. The therapeutic benefits seen with flupirtine relate to its unique pharmacological properties. Flupirtine displays indirect NDMA receptor antagonism via activation of potassium channels and is the first representative of a pharmacological class denoted the 'selective neuronal potassium channel openers'. The generation of the M-current is facilitated by flupirtine via the opening of neuronal Kv7 potassium channels. The opening of these channels inhibits exaggerated neuronal action potential generation and controls neuronal excitability. Neuronal hyperexcitability is a physiological component of many pain states such as chronic pain, migraine and neurogenic pain.

Raclopride is a salicylamide neuroleptic, that acts as a selective antagonist of D2 dopamine receptors both in vitro and in vivo. Tritium-labelled raclopride has properties that demonstrate its usefulness as a radioligand for the labelling of dopamine-D2 receptors : 3H-Raclopride has a high affinity for the rat and human dopamine-D2 receptors, the non-specific binding of 3H-raclopride is very low, not exceeding 5% of the total binding and the distribution of the 3H-raclopride binding sites in the brain closely correlates with the dopaminergic innervation. The binding of 3H-raclopride is blocked by dopamine-D2 agonists and antagonists, while the D1 agonist SKF 38393 and the Dl antagonist SCH 23390 have much less potency. The interaction of dopamine with 3H-raclopride binding results in a shallow competition curve, which suggests that 3H-raclopride, similar to other dopamine-D2 radioligands, labels both high and low agonist affinity states of the dopamine-D2 receptor. The in vivo receptor binding studies performed with 3H-raclopride also demonstrate its favorable properties as a dopamine-D2 receptor marker in vivo In contrast to some other compounds used as radioligands, raclopride enters the brain readily and binds with a low component of non-specific binding in all dopamine-rich brain areas. A saturation curve may be achieved in vivo binding studies since injections of increasing concentrations of 3H-raclopride appears to be saturated at concentrations above 25 mkCi (corresponding to approximately 5 nmol/kg). Raclopride antagonizes apomorphine-induced hyperactivity in the rat at low doses (ED50 = 130 nM/kg i.p.) but induces catalepsy only at much higher doses (ED50 = 27 mkM/kg i.p.). Radiolabelled raclopride has been used as a ligand for in vitro and in vivo autoradiography in rat and primate brains. Raclopride C 11 is used with positron emission tomography (PET) as a clinical research tool to determine dopamine type 2 (D 2) receptor density in the human brain under normal and pathological conditions. For example, raclopride C 11 used in PET studies has served to confirm the age-related decrease in striatal dopamine D2 receptor density, which may be associated with a decline in the motor as well as cognitive functions. In patients with Alzheimer's disease, raclopride C 11 may be used to examine neuroreceptor distribution and quantities, which may help in the analysis of degenerative alterations of neuron populations and neuroreceptor systems in patients with this disease. In Huntington's disease, in which degeneration of neostriatal interneurons occurs (postsynaptic to the dopaminergic input), specific binding of raclopride C 11 to D 2 receptors may serve as one of the parameters in predicting performance in cognitive tasks.

Clebopride is a dopamine antagonist drug. It is used to treat functional gastrointestinal disorder such as nausea or vomiting. Unchanged parent drug was the most abundant compound in human urine. Major metabolites included the hydroxylation at benzyl group to yield carbinolamine and its further N-dealkylation product, and the piperidine ring hydroxylation/oxidation metabolite (a lactam).

Belotecan is a semisynthetic analogue of camptothecin containing a 2-(N-isopropylamino) ethyl group linkage at position C-7 of the camptothecin ring. It stabilizes the complex formed between topoisomerase I and DNA, thereby preventing the religation of DNA breaks. This leads to an inhibition of DNA replication and triggers apoptotic cell death. Belotecan was approved in Korea under the name Camtobell for the treatment of patients with ovarian and small cell lung cancers.

Vernakalant is a new antiarrhythmic drug that acts selectively in the atrium, targeting atrial specific channels. Vernakalant is an anti-arrhythmic medicine that acts preferentially in the atria by prolonging atrial refractoriness and by rate-dependently slowing impulse conduction. These anti-fibrillatory actions on refractoriness and conduction are thought to suppress reentry, and are potentiated in the atria during atrial fibrillation. The preferential effects of vernakalant on the atria are postulated to result from its block of currents that are expressed in the atria (e.g., the ultra-rapid delayed rectifier potassium current; and the acetylcholine-activated potassium current), but not in the ventricles, as well as the unique electrophysiologic condition of the fibrillating atria. An oral formulation of vernakalant is in phase II development as a long-term maintenance therapy for patients with atrial fibrillation. An intravenous formulation of vernakalant has been launched in most countries in Europe and Latin America, and in Hong Kong, for the acute conversion of atrial fibrillation. The product has been approved for the acute conversion of atrial fibrillation in South Africa, Iceland, Turkey and is awaiting approval for the same indication in Canada. Phase III development of the IV formulation is ongoing at sites in Asia, and development is currently on hold in the US.

A potent, selective and orally active receptor antagonist of leukotriene D4, verlukast (MK-571), was discovered and developed from a styrylquinoline lead structure based on a hypothetical model of the leukotriene D4 receptor. MK-571 blocks the action of LTD4 in animals and man, and is effective in a number of animal models of antigen-induced bronchoconstriction at plasma concentration at or below 2 ug/mL. MK-571 also blocks antigen-induced asthmatic responses in man. MK-571 is a potent and selective leukotriene D4 (LTD4) antagonist and ABCC multidrug resistance protein 1(MRP1) inhibitor. The cysteinyl leukotrienes (CysLTs), LTC4, LTD4, and LTE4, mediate their actions through two distinct G-protein coupled receptors. LTD4 is the preferred ligand for the CysLT1 receptor, whereas LTC4 and LTD4 bind with approximately equal affinity to the CysLT2 receptor. MK-571 is a selective, orally active CysLT1 receptor antagonist. It blocks the binding of LTD4, but not LTC4, to human and guinea pig lung membranes with Ki values of 0.22 nM and 2.1 nM, respectively. MK-571 effectively blocks LTD4 activation of recombinant human and mouse CysLT1 receptors but is ineffective at blocking LTC4 or LTD4 activation of the recombinant human or murine CysLT2 receptors.