Tetrazolast (also known as MDL 26,024GO) is a tetrazoloquinoline derivative patented by Merrell Dow Pharmaceuticals, Inc. as an antiallergic and antiasthmatic agent. Tetrazolast was shown to be an orally absorbed mediator release inhibitor in the rat passive cutaneous anaphylaxis and passive peritoneal anaphylaxis tests. In addition, the compound was shown to both elicit and inhibit elicitation of the Bezold-Jarisch reflex in the dog. Tetrazolast also significantly reduced Ascaris-induced changes in pulmonary mechanics in cynomolgus monkeys. The compound inhibited both early and late phase antigen induced-changes in Ascaris-sensitive sheep, as well as the increased airway hyperreactivity which normally follows antigen challenge.

Ocfentanil, a compound structurally similar to the opioid analgesic fentanyl, was developed in the early 1990’s with the hope that it would provide a better clinical safety profile than fentanyl. The receptor pharmacology of ocfentanil appears to share pharmacodynamic effects with fentanyl and other μ opioid agonists, including analgesia, sedation, and respiratory depression. In rodents, ocfentanil was approximately 2.5 times more potent as an analgesic than fentanyl and had a shorter duration of action. Because the preclinical research suggested that ocfentanil had a better safety profile than fentanyl, it was selected for clinical evaluation. Like other μ opioid agonists, ocfentanil has been reported to produce itching, nausea, sedation, and severe respiratory depression. Chest pain, psychosis, and agitation have also been reported. In humans, however, ocfentanil had a similar potency (3 ug/kg ocfentanil produced effects that were comparable to 5 ug/kg fentanyl) and side-effects profile as fentanyl so further clinical development was discontinued. Ocfentanil is not approved in any country for medical useand is under national control in Canada, the United Kingdom, and China.

Sanfetrinem cilexetil (formerly known as GV 118819), a beta-lactam antibiotic, is the oral prodrug of sanfetrinem. Experiments on rodents have revealed that sanfetrinem cilexetil had strong antibacterial activity in vitro and good pharmacokinetic behavior in mice. This drug was suitable for the treatment of infections caused by a variety of bacteria and participated in a phase II clinical trial. However, this study was discontinued.

Atrasentan (ABT-627, A-127722) is a selective endothelin A receptor antagonist. Atrasentan is being developed by AbbVie as an oral treatment for diabetic nephropathies.Abbott Laboratories was conducting clinical development of atrasentan for the treatment of certain cancers, including phase II trials for prostate cancer. However, no recent development has been reported for cancer indications and development is presumed to be discontinued.

Ciclazindol is an indole derivative and monoamine uptake inhibitor patented by pharmaceutical company John Wyeth and Brother Ltd. as an antidepressant. Besides that, Ciclazindol is effective anorectic agent, inducing weight loss in rats and man. Ciclazindol was shown to inhibit ATP-sensitive K+ (K(ATP)) channel currents and stimulate insulin secretion from CRI-G1 insulin-secreting cells. The inhibition of KATP channel currents by ciclazindol is unaffected by the removal of intracellular Mg2+ ions and after trypsinization of the cytoplasmic surface of excised patches, treatments known to abolish sulphonylurea sensitivity.

Mariptiline is an antidepressant compound.

Rosamaricin is a macrolide antibiotic similar to erythromycin. This compound is more effective against Gram-negative bacteria than erythromycin, especially in the prostate where rosamaricin was shown to be more concentrated than erythromycin in dogs. Rosamaricin has antibiotic activity against Neisseria gonorrhoeae, Chlamydia trachomatis, Ureaplasma urealyticum and Mycoplasma hominis. When the drug was compared with penicillin G in the treatment of pneumococcal meningitis in rabbits it was found to be less effective than penicillin G, as measured by bacterial clearance from cerebrospinal fluid and by treatment outcome. No information on the current use of this compound is available.

Medroxalol is a competitive antagonist at alpha1-adrenergic receptors and beta1-adrenergic receptors. Medroxalol also an agonist at beta2-adrenergic receptors. Medroxalol exerts antihypertensive and vasodilating effects. It was concluded that the principal action of medroxalol was to produce a fall in blood pressure by decreasing peripheral vascular resistance more than cardiac output.

Thyromedan is a thyroalkanoic acid derivative with hypocholesterolemic activity. In clinical trials, Thyromedan in daily doses of 8 to 32 mg caused a decrease in serum cholesterol levels. The serum total triglycerides and the α- and β-lipoprotein partition of cholesterol and triglycerides were unaffected.

Butaclamol is an antipsychotic drug, which was studied for the treatment of schizophrenia. This drug has never marketed and now is used in research, because of its action as a dopamine receptor-blocking agent. Butaclamol consists of the two forms: (-)-butaclamol, an inactive drug and (+)-butaclamol, a potent neuroleptic drug.