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.