2-Adamantanamine produces prolonged spinal block in rats

•Intrathecal 2-adamantanamine provoked spinal block dose-dependently.•2-Adamantanamine was less potent than mepivacaine in spinal anesthesia.•2-Adamantanamine produced more nociceptive block than motor block.•The duration caused by 2-adamantanamine was longer than that caused by mepivacaine. We aimed to investigate the local anesthetic effect of 2-adamantanamine in spinal anesthesia. The dose–response curves were constructed after intrathecally injecting the rats with five doses of 2-adamantanamine and a common local anesthetic mepivacaine. The quality and duration of 2-adamantanamine at producing spinal nociceptive, proprioceptive and motor block were compared with that of mepivacaine. We revealed that 2-adamantanamine provoked spinal nociceptive, proprioceptive and motor block dose-dependently. On the 50% effective dose (ED50) basis, the rank of potency was mepivacaine >2-adamantanamine at producing spinal nociceptive, proprioceptive and motor block (p