SNX-111 is the first neuronal N-type, voltage-sensitive calcium channel (VSCC) blocker to enter clinical drug development. Areas of potential therapeutic utility include treatment of nociceptive and neuropathic pain and neuroprotection after ischemic brain injury. The data presented demonstrate that SNX-111 is biologically active in humans and indicate for the first time a neurophysiologic function of N-type VSCCs in humans.