Mesocarb (sydnocarb or 3-(beta-phenylisopropyl)-N-phenylcarbamoylsydnonimine) is a psychomotor stimulant N-alkylated amphetamine derivative. Mesocarb is a selective inhibitor of dopamine uptake, it potently blocks dopamine transporter. It is very likely that mesocarb is being used by drug addicts. Mesocarb is included in the World Anti-Doping Agency’s list of substances and methods that are prohibited in sports. It is used in Russia for the treatment of a variety of neuropsychiatric comorbidities.

Mespiperone C-11 (3-N-[11C] methylspiperone) is a radiolabeled 3-N-methylspiperone. 3-N-methylspiperone is high-affinity D2/3 dopamine and 5-HT2A serotonin receptor antagonist. It has been studied as a positron emission tomography (PET) tracer for imaging D2/3 and 5HT2A receptor densities.

Idoxifene (also known as CB 7432), a novel selective estrogen receptor modulator, is originally discovered at the CRC Centre for Cancer Therapeutics, Institute. This drug participated in clinical trials phase II in patients with locally advanced/metastatic breast cancer resistant to tamoxifen. In addition, in phase III in postmenopausal women after one year of idoxifene treatment. However, both studies were discontinued because of insufficient effectiveness.

Rifalazil (also known as KRM-1648) is a derivative of the antibiotic rifamycin. This orally administered ansamycin is under evaluation for treatment of various bacterial infections. Rifalazil kills bacterial cells by blocking off the β-subunit in RNA polymerase. This drug was originally developed as a therapeutic agent to replace rifampin in the treatment of tuberculosis. It also showed potential to treat indications caused by chlamydia trachomatis and chlamydia pneumoniae. Furthermore, it has been suggested as a potential drug in the treatment of gastric ulcer disease (which is caused by Helicobacter pylori) and antibiotic-associated colitis. Phase II studies evaluated the efficacy and safety of this drug in patients with chlamydia trachomatis and chlamydia seropositive patients. A phase 3 study was initiated including chlamydia seropositive patients. However, the development of rifalazil was terminated in 2013 due to severe side effects.

Minalrestat was developed by Wyeth-Ayerst as an aldose reductase inhibitor. It is known, the aldose reductase inhibition might ameliorate diabetic complications through the correction of the altered microvascular reactivity by a mechanism that involves NO and membrane hyperpolarization. That is why minalrestat was studied for patients with diabetic retinopathy. However, Wyeth discontinued development of minalrestat.

Iocanlidic Acid I-123 is a radiolabeled phenylfatty acid derivative studied as a diagnostic agent for myocardial imaging

Phencyclidine is an illegal, hallucinogenic drug that was initially used as an anesthetic agent in the 1950s and early 1960s, but was then withdrawn in 1965 because of dissociative hallucinogenic effects that were often disturbing and sometimes severe and prolonged. Phencyclidine is a noncompetitive NMDA (N-methyl-D-aspartate) receptor antagonist and glutamate receptor antagonist, but also interacts with other receptor sites, and may have effects with dopamine, opioid and nicotinic receptors. Phencyclidine disrupts the functioning of receptors for the neurotransmitter glutamate, which plays a major role in the perception of pain as well as in learning, memory, and emotion. It also influences the actions of the neurotransmitter dopamine, which causes the euphoria associated with drug use. Phencyclidine overdose deaths may occur after taking a large dose, though many phencyclidine related deaths result from delusions and other psychological consequences of the drug’s use. There have been reports of death due to accidental drowning, leaping from high places, and motor vehicle accidents in addition to violent episodes of self-mutilation, suicides, and homicides.

Quilostigmine (also known as NXX-066) is an isoquinolinecarboxylate patented by Hoechst-Roussel Pharmaceuticals Inc as a memory enhancer. Quilostigmine acts as acetylcholinesterase inhibitor and studies as a potential drug for treating Alzheimer’s disease. Quilostigmine is well absorbed from the gastrointestinal tract, but the oral bioavailability poor to moderate in rats and dogs because of pre-systemic metabolism. In preclinical studies has demonstrated activity in animal models of memory function. In clinical trials, Quilostigmine was well tolerated in healthy subjects up to a single dose of 64 mg and multiple doses of 60 mg QD for seven days

Beloxepin (or ADL6906), a novel dual norepinephrine reuptake inhibitor and serotonin receptor antagonist, was investigated for the treatment of the pain and Major depressive disorder, but these studies were discontinued.