Merz Pharmaceuticals GmbH and Forest Laboratories Inc are developing neramexane (MRZ 2/579), an oral N-methyl-D-aspartate antagonist, as a potential neuroprotectant for various central nervous system disorders, including Alzheimer's disease, and for the potential treatment of drug and alcohol dependence, and pain. Similar to memantine, neramexane is an NMDA receptor channel blocker with moderate affinity. It displays voltage dependency, and rapid unblocking kinetics. Neramexane also has been shown to block acetylcholine-evoked responses by antagonizing the alpha-9 alpha-10 nicotinic acetylcholine receptor. Neramexane has a novel mechanism of action and is expected to improve the patients' psychological suffering and difficulties in their life associated with tinnitus by its properties to inhibit the abnormal activity and electric potential of nerve in the inner ear, nerve and cerebral cortex. Neramexane is expected to improve the patients' psychological suffering and difficulties in their life associated with tinnitus by inhibiting the excessive excitation in the auditory pathway from the inner ear to nerve and cerebral cortex via mainly its two pharmacological properties. 1) Neramexane inhibits the excessive nerve excitation in the auditory pathway between the inner ear and cerebral cortex via NMDA antagonistic activity. 2) Neramexane inhibits the nerve excitation in the inner ear via nicotinic acetylcholine receptor antagonistic activity. A phase III trial is currently under investigation for tinnitus.

Neldazosin, a prazosin derivative, is an alpha adrenoreceptor antagonist. It is an antihypertensive substance.

Nardeterol (SOM-1122) was found to be a high-affinity, partial agonist for beta adrenergic receptors. SOM-1122 inhibited the binding of [125I]iodopindolol to membranes prepared from rat cerebral cortex and cerebellum. SOM-1122 bound to beta adrenergic receptors in vitro and in vivo, increased levels of cyclic AMP in slices of cerebral cortex in vitro and reduced the density of beta adrenergic receptors after chronic treatment. SOM-1122 also was found to be behaviorally active. It reduced locomotor activity and altered behavior maintained under DRL and multiple FlFR schedules. These behavioral effects of SOM-1122 are similar to those reported previously for other centrally acting beta adrenergic agonists.

Napirimus is an immunosuppressant agent.

Oxifungin was developed as an antifungal agent. However, information about the current use of this compound is not available.

Nabazenil is a synthetic cannabinoid receptor agonist, which has anticonvulsant properties. Nabazenil was undergoing preclinical trials with HG Pars in the USA.

Oletimol was developed as an antirheumatic agent that has never been marketed. Information about the current use of this drug is not available.

Ozolinone, an active metabolite of diuretic etozoline was studied also as a loop diuretic. Experiments on dogs have shown that ozolinone, induced stereoselective and prostaglandin-dependent renin secretion, which was involved in the regulation of intra-renal hemodynamics. Information about the current use of this drug is not available.

Indisulam (also known as E7070) is a sulfonamide derivative patented by Japanese pharmaceutical company Eisai Co. as antitumor agent. Indisulam inhibits cyclin-dependent kinases (CDK), which regulate cell cycle progression and are usually over-expressed in cancerous cells. Inhibition of CDK results in G1/S phase arrest of the cell cycle, and may lead to induction of apoptosis and inhibition of tumor cell proliferation. Preclinical and clinical studies have established the synergy of indisulam with nucleoside analogs as well as topoisomerase inhibitors. These combinations were tolerated with acceptable toxicities, including diarrhea, vomiting, and myelosuppression. In Phase II clinical trials Combination of indisulam with DNA‐damaging agent (idarubicin) and nucleoside analog (cytarabine) in patients with relapsed and refractory AML is effective and largely well tolerated.