Developed by Solvay Pharmaceuticals, cilansetron is a 5-HT3 antagonist indicated for the treatment of diarrhoea-predominant irritable bowel syndrome (IBS). 5-HT(3) receptor antagonists such as cilansetron have been shown to affect gastrointestinal motility. With Phase III registration trials on cilansetron completed, Solvay filed for regulatory approval in Europe and the US in 2004. To ensure that cilansetron is only prescribed to patients with diarrhoea-predominant IBS, Solvay’s regulatory submission included an extensive appropriate use plan. In April 2005, however, Solvay received a “non-approvable” letter from the FDA and a request for additional data to support product registration in the US. Towards the end of 2005, the company announced that it had suspended registration of cilansetron in the US. Meanwhile, discussions continue with the UK’s MHRA about European marketing approval for cilansetron. In 2005, the MHRA also declined to approve cilansetron. Both the agencies requested additional clinical data to further assess the risk-benefit ratio of the compound. Despite the drug being rejected for approval, Solvay believed in the product and felt that the clinical data demonstrated important benefits for men and women suffering from diarrhoea-predominant IBS. However, taking into account the amount of clinical work requested and other business considerations, the company decided to end the development and regulatory activities for cilansetron. The clinical efficacy and safety of cilansetron was established in a series of clinical trials, including a large-scale international Phase III programme involving over 4,000 patients. Overall, results from these trials showed that cilansetron is significantly more effective than placebo in male and female patients with diarrhoea-predominant IBS, an important finding given the traditionally high placebo response rates seen in clinical trials of IBS drugs. Overall responder rates (adequate relief in at least 50% of weekly responses) for patients treated with cilansetron ranged from 52% to 61% compared with 37% to 46% for placebo recipients. The most common side effect of cilansetron is constipation, which is seen in 3-12% of subjects at 6 months. Ischemic colitis, a side effect associated with previous drugs of this class, has been seen in eight subjects (six women and two men) to date. All of these ischemic colitis events have been self-limited and did not require surgery. Because of its high degree of efficacy, the fact that it was well tolerated by the overwhelming majority of patients and that it showed efficacy in both genders, cilansetron represented a major advance in the treatment of irritable bowel syndrome with diarrhea predominance.

levomethadone, or R-(−)-methadone, is the active enantiomer of methadone; having approximately 50x the potency of the S-(+)-enantiomer as well as greater μ-opioid receptor selectivity.

Propionylpromazine is used as a neuroleptic to combat stress in pets and farm animals. The main use is to combat stress in the transport of pigs. Propionylpromazine was in common use in veterinary practice in the 1950s and 1960s. Propionylpromazine is of interest to JECFA because of the illicit use at pharmacological dosage (< 1 mg/kg i.m.) in the immediate pre-slaughter period.

Cinepazet is an ethyl ester of cinepazic acid. It acts by inhibiting the influx of extracellular calcium into cells through the slow calcium channel in the cell membrane. In the 1970s cinepazet was marketed in France and Italy under tradename Vascoril for the treatment of angina.

Iobenguane, mainly use as a radiopharmaceutical, used in a scintigraphy method called MIBG scan. Synthetic guanethidine derivative that locates phaeochromocytomas and neuroblastomas. The radioisotope used can either be iodine-123 for imaging or iodine-131 for destruction of tissues that metabolize noradrenaline. Iodine 123 is a cyclotron-produced radionuclide that decays to Te 123 by electron capture. Images are produced by a I123 MIBG scintigraphy. It localizes to adrenergic tissue and thus can be used to identify the location of tumors such as pheochromocytomas and neuroblastomas. With I-131 it can also be used to eradicate tumor cells that take up and metabolize norepinephrine. The radioactive iodine component is responsible for its imaging properties. Iobenguane and guanethidine are substrates for the norepinephrine transporter (NET) and accumulate by the uptake mechanism into presynaptic nerve endings. Unlike norepinephrine, these drugs are protonated under physiologic conditions; therefore, they do not cross the blood–brain barrier and in vivo uptake is limited primarily to systemic neuronal tissue. The accumulation of iobenguane in myocardial tissue is also dictated by the high fraction of aortic blood flow that enters the coronary arteries. This physiology constitutes an ideal molecular targeting mechanism for diagnosis of various cardiac diseases, including heart failure, heart transplant rejection, ischemic heart disease, dysautonomia, and drug-induced cardiotoxicity, as well as cardiac neuropathy related to diabetes mellitus and Parkinson disease

Alrestatin, an inhibitor of aldose reductase, was studied in clinical trials for the treatment of diabetes. But this study was discontinued, because of the high hepatotoxicity events.

BUTETHAMINE, an ester of the para-aminobenzoic acid, is a local anesthetic formerly used in dentistry. It has diminished toxicity and increased the speed of action as compared with procaine.

Amadione is a steroidal progestogenic antiandrogen. Its anti-androgenic properties were confirmed by blockade of androgen-induced increase in seminal acid phosphatase content.

Oxilofrine is a sympathomimetic used to treat hypotensive states, with cardiac stimulatory effects similar to those of ephedrine. It has never been approved for use in the USA as a prescription drug or as a dietary supplement. Oxilofrine has been found (1) to act predominantly as a beta1 agonist increasing the speed and force of heart muscle contraction (inotropic effects), specifically, increasing left ventricular ejection fraction and stroke volume; (2) to increase blood pressure; (3) to have variable effects on heart rate; and (4) to potentially increase oxygen uptake by the lungs.