FERROQUINE, a ferrocene-quinoline conjugate, is an antimalarial drug currently undergoing a clinical evaluation. It is also a promising candidate for repositioning as cancer therapeutics.

RGH-896 (radiprodi) is orally active and selective NMDA NR2B antagonist, a potential therapeutic agent in treatment of neuropathic pain and possibly other chronic pain conditions. It blocks pain signaling without interacting with other NMDA receptor subtypes thus potentially improving therapeutic index and side effect profile. RGH-896 is the first of this group and is currently in early clinical development. Forest and Richter initiated a Phase IIb study in neuropathic pain in the United Stated in the second half of 2006. The drug did not produce significant reductions in patient-reported pain scores for all the dosages tested. Forest says that it and Gedeon Richter will review the findings before making a decision about the further development of radiprodil. In addition to neuropathic pain, the companies intend to investigate various other pain conditions and possibly CNS indications not related to pain. Forest will pay Richter undisclosed upfront and milestone payments in addition to royalties and will have exclusive rights in the U.S. and Canada. The two companies will jointly fund the development program. RGH-896 has patent applications that provide patent protection until at least 2022.

Meletimide (R 5183) is a powerful anticholinergic agent with pronounced peripheral and central action.

Ebselen is a small molecule mimic and inducer of glutathione peroxidase activity and possesses antioxidant and anti-inflammatory properties. This drug has been investigated in phase II clinical trials for the treatment of Meniere's disease, bipolar disorder and in the prevention of hearing loss. Besides, experiments on mice have shown that ZIKV infection could be on the list for potential use of ebselen. It alleviates testicular pathology in mice with Zika virus infection and prevents its sexual transmission. Ebselen has various mechanisms of action. It binds to the N-terminal domain of soluble epoxide hydrolase and chemically reacts with the enzyme to quickly and irreversibly inhibit one of the enzymes' activity: phosphatase (Nterm-phos). Besides, ebselen inhibits inositol monophosphatase and thus exhibits lithium-like on human central nervous system (CNS) function. In addition, ebselen inhibits the G4 isoform of acetylcholinesterase. It is a well-known relationship between the cholinergic system and learning, memory and other common cognitive processes, thus ebselen can be studied for the treatment of memory impairment diseases.

Levophacetoperane is a piperidine derivative. Levofacetoperane is a sympathomimetic central nervous system stimulant and is commonly used to treat depression. Levophacetoperane is also a known analeptic and is strongly linked to apnea reversal in dogs after a single intravenous injection.

Vabicaserin is a 5-hydroxytryptamine 2C (5-HT2C) receptor-selective agonist with an EC50 of 8 nM. Pfizer was developing vabicaserin, an oral serotonin (5-HT)2C receptor agonist, for the treatment of schizophrenia and bipolar disorder. Vabicaserin decreases nucleus accumbens extracellular dopamine levels in rats, without affecting striatal dopamine, indicating mesolimbic selectivity. Vabicaserin had been in phase II clinical trials for the treatment of schizophrenia. However, research of Vabicaserin for the treatment schizophrenia and obesity was discontinued.

Edivoxetine (LY-2216684) is a highly selective norepinephrine reuptake inhibitor. It is under development as adjunctive or monotherapy of disorders believed to be associated with alterations in norepinephrine transmission within the central nervous system. Currently, edivoxetine is being studied in the treatment of attention-deficit hyperactivity disorder. Edivoxetine development in the treatment of major depressive disorder has been discontinued.

Esmirtazapine (S-(+)mirtazapine or ORG-50081) is an enantiomer of mirtazapine (REMERON®), a high-affinity antagonist at 5-HT2/5-HT3 and H1 receptors, used in the treatment of depression. Esmirtazapine has a shorter plasma half-life than the R(−) enantiomer. Esmirtazapine is preferentially metabolized into an 8-hydroxy glucuronide. Organon was developing esmirtazapine for the treatment of hot flushes (vasomotor symptoms) associated with the menopause and insomnia.

Conessine is a plant steroid alkaloid that acts as a potent and specific antagonist of histamine H3 receptors. Conessine displayed high affinity at both rat and human H3 receptors (pKi = 7.61 and 8.27) and generally high selectivity against other sites, including histamine receptors H1, H2, and H4. Conessine was found to efficiently penetrate the CNS and reach very high brain concentrations. Although the very slow CNS clearance and strong binding to adrenergic receptors discouraged focus on conessine itself for further development, its potency and novel steroid-based skeleton motivated further chemical investigation. Modification based on introducing diversity at the 3-nitrogen position generated a new series of H3 antagonists with higher in vitro potency, improved target selectivity, and more favorable drug-like properties. Conessine also has high affinity for the adrenergic receptors. Conessine has being shown to possess anti-malarial activity. In India conessine finds therapeutic use for treatment of dysentery and helminthic disorders.

Sulrnazole (the former AR-L 115 BS) is a benzimidazole derivative with positive inotropic, positive chronotropic and vasodilator effects. Sulrnazole also has been shown to improve cardiac index and reduce pulmonary capillary wedge pressure without significant change in heart rate or arterial pressure. Intravenous administration caused a 217 per cent increase in cardiac output with a 25 per cent decrease in pulmonary wedge pressure. Short-term oral administration resulted in a 317 per cent increase in cardiac index and a 317 per cent increase in ejection fraction. Side effects have included visual blurring and transient colour blindness. Sulmazol has been demonstrated to improve regional wall motion in patients with ischemic heart disease and to abolish pacing-induced ischemia. Sulrnazole is an A1 adenosine receptor antagonist. It is also a phosphodiesterase inhibitor.