Metamfepramone (dimethylcathinone, dimethylpropion, and dimepropion) was synthesized by various routes in the 1930s and 1940s and clinically evaluated as anorectic as well as a treatment of hypotension and symptoms of the common cold. It was widely used for the treatment of the common cold or hypotonic conditions. Due to its stimulating properties and its rapid metabolism resulting in major degradation products such as methylpseudoephedrine and methcathinone, it has been considered relevant for doping controls by the World Anti-Doping Agency (WADA). Metamfepramone was marketed as an appetite suppressant, but was made illegal in 2006.

MK-0359 (L-454560) is a selective and potent type 4 phosphodiesterases (PDE4) inhibitor, which binds to both the apo-(Mg2+-free) and holoenzyme states of PDE4. This compound successfully has passed the phase II clinical trial for the treatment of asthma, Pulmonary Disease, Chronic Obstructive (COPD) and Rheumatoid Arthritis. However, there is no information about the further research of this drug.

Ombrabulin is an experimental drug candidate discovered by Ajinomoto and further developed by Sanofi-Aventis for cancer treatment. Ombrabulin is a synthetic water-soluble analog of combretastatin A4, derived from the South African willow bush (Combretum caffrum), with potential vascular-disrupting and antineoplastic activities. Ombrabulin binds to the colchicine binding site of endothelial cell tubulin, inhibiting tubulin polymerization and inducing mitotic arrest and apoptosis in endothelial cells. As apoptotic endothelial cells detach from their substrate, tumor blood vessels collapse; the acute disruption of tumor blood flow may result in tumor necrosis. Ombrabulin has been used in trials studying the treatment of Sarcoma, Neoplasms, Solid Tumor, Neoplasms, Malignant, and Advanced Solid Tumors, among others. In January 2013, Sanofi said it discontinued development of Ombrabulin after disappointing results from phase III clinical trials.

Darglitazone is a member of the thiazolidinedione class of drugs and an agonist of peroxisome proliferator-activated receptor-γ (PPAR-γ), an orphan member of the nuclear receptor superfamily of transcription factors. It has a variety of insulin-sensitizing effects, such as improving glycemic and lipidemic control, and is used in the treatment of metabolic disorders such as type II diabetes. Darglitazone sodium had been in phase I clinical trials by Pfizer for the treatment of type 2 diabetes. However, this study has been discontinued.

Pipequaline (PK-8165, 2-phenyl-4[2-(4-piperidinyl) ethyl]quinoline) is a benzodiazepine receptor partial agonist.

Anidoxime is unrelated to other analgesic agents in clinical use. It is the hydrochloride salt of 0-(4-methoxyphenyl-carboxyl)-3-diethylamino-propiophenone oxime, with an empirical formula C21H27N3O3 HCl. It was in clinical trial as an oral analgesic agent.

Fosbretabulin (Combretastatin A4 phosphate, CA4P) is the lead compound of a relatively new class of agents termed vascular disrupting agents that target existing tumor blood vessels. Rapid tumor blood flow shutdown has been demonstrated in preclinical models and patients by various techniques such as dynamic contrast-enhanced MRI, perfusion computed tomography and PET scans following CA4P infusion. CA4P typically induces rapid tumor necrosis in the center of the tumor and leaves a rim of viable cells in the periphery. In oncology, CA4P does not appear to be that active by itself, but may be more efficacious when combined with chemotherapy, antiangiogenic therapy and radiation therapy. Combretastatin was initially isolated from the root bark of the South African Bush willow Combretum caffrum in 1982 by Pettit and colleagues at the Arizona State University (AZ, USA). Combretastatin A4 phosphate binds avidly to tubulin at the colchicine-binding site to inhibit microtubule assembly and destabilize the cytoskeleton. CA4P is a tubulin-binding agent that binds at or near the colchicine binding site of β-tubulin (Kd = 0.40 uM), inhibits tubulin assembly with IC50 of 2.4 uM. Fosbretabulin has orphan drug status in the EU and the US for the treatment of ATC (Anaplastic Thyroid Cancer). Later the development of this drug was discontinued.

Pretamazium is thiazolium derivative patented by UK pharmaceutical company Wellcome Foundation Ltd. as antiphrastic compound, that active against parasitic nematodes.