Inaperisone is a pyrrolidinopropiophenone derivative patented by Japanese pharmaceutical company Hokuriku Pharmaceutical Co. as muscle-relaxant and antispasmodic agent.

Brequinar is a synthetic quinolinecarboxylic acid analogue with antineoplastic properties. Brequinar inhibits the enzyme dihydroorotate dehydrogenase, thereby blocking de novo pyrimidine biosynthesis. This agent may also enhance the in vivo antitumor effect of antineoplastic agents such as 5-FU. Brequinar had been in phase II clinical trials by Bristol-Myers Squibb for the treatment of cancer and transplant rejection. However, this research has been discontinued. Brequinar had been also in preclinical studys for the treatment of cytomegalovirus infections. However, this research has been discontinued.

Faxeladol (GRT9906) is a μ-opioid receptor agonist and inhibitor of noradrenalin/serotonin re-uptake. Faxeladol was being studied in the treatment of fibromyalgia and neuropathic pain, however its development has been discontinued.

Baquiloprim, a drug that was used in veterinary medicine, e.g. in combination with sulphadimidine for the treatment of diarrhea in calves. However, the drug has vanished from the use mainly for commercial reason.

Dersalazine is a locally-acting compound. It is a potent platelet activating factor (PAF)-antagonist. Dersalazine inhibited IL-1beta or TNF-alpha production in THP-1 or U937 cells, respectively. Dersalazine sodium reduced colonic proinflammatory cytokines IL-1b, IL-6, and IL-17 in dextran sodium sulphate (DSS)–induced colitis. After oral administration, dersalazine sodium is mostly unabsorbed until it reaches the large bowel where the azo bond is reduced by bacteria releasing the active compound. Dersalazine had been in phase I clinical trial for the treatment of ulcerative colitis. No serious adverse reactions were detected in clinical trial. However, no recent development has been reported.

Pyroxamine (also known as AHR 224) is benzhydryl ethers of 3-pyrrolidinol patented by A. H. Robins Co., Inc. as antihistamine with bronchodilation activity. In preclinical studies, Pyroxamine shows moderate inhibition of histamine-induced ulceration in guinea pigs

Galdansetron is a selective serotonin antagonist compound that is effective against vomiting and nausea. This type of drug is used to treat motion sickness or side effects of chemotherapy or anesthetics.

Schering published xanthine PDE5 inhibitors with amino substituents in the imidazole 2-position, such as Dasantafil. Dasantafil, also known as SCH-446132, is a PDE5A inhibitor potentially for the treatment of erectile dysfunction. It had been in phase II clinical trials but there is no report for this compound recently.

Soretolide is an orally active benzamide derivative with anticonvulsant effects and a similar profile of activity to carbamazepine. In animal models, soretolide showed an anticonvulsant profile similar to carbamazepine, being active in the maximal electroshock test and poorly active against pentylenetetrazole-induced seizures. Researchers at the University of Washington, USA and Laboratoires Biocodex, France were investigating the potential use of soretolide as an anticonvulsant. However, development of the compound appears to have been discontinued.

Altinicline (SIB-1508Y, SIB-1765F) is a drug which acts as an agonist at neural nicotinic acetylcholine receptors with high selectivity for the α4β2 subtype. It stimulates release of dopamine and acetylcholine in the brain in both rodent and primate models, and progressed as far as Phase II clinical trials for Parkinson's disease, where "no antiparkinsonian or cognitive-enhancing effects were demonstrated", although its current status is unclear.