title: Intrathecal amantadine for prolonged spinal blockade of sensory and motor functions in rats.
abstract: We aimed to compare the hypothesized local anesthetic action of amantadine (1-adamantanamine) with that of the known local anesthetic mepivacaine. Motor, proprioceptive, and nociceptive functions were evaluated in rats after intrathecal administration. Amantadine elicited spinal anesthesia in a dose-related fashion and produced a better sensory-selective action over motor blockade (P < 0.01). On the 50% effective dose (ED50 ) basis, the rank of potency on spinal motor, proprioceptive, and nociceptive block was mepivacaine > amantadine (P < 0.01 for the differences). Amantadine (63.5 μmol/kg) and mepivacaine (7.1 μmol/kg) produced complete spinal block of motor function, proprioception, and nociception. On an equipotent basis (ED25 , ED50 , and ED75 ), the duration of amantadine was longer (P < 0.01) than that of mepivacaine on spinal motor, proprioceptive, and nociceptive block. Our preclinical data demonstrated that amantadine was less potent than mepivacaine at producing spinal anesthesia. The spinal block duration produced by amantadine was greater than that produced by mepivacaine. Both amantadine and mepivacaine produced a markedly nociceptive-specific blockade.
authors.affiliation: Department of Anesthesiology, Chi-Mei Medical Center, Yong Kang, Tainan, Taiwan.
authors.forename: Jann-Inn
authors.initials: JI
authors.lastname: Tzeng
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Chung-Dann
authors.initials: CD
authors.lastname: Kan
authors.affiliation: Department of Pediatrics, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Jieh-Neng
authors.initials: JN
authors.lastname: Wang
authors.affiliation: Department of Medical Research, Chi-Mei Medical Center, Tainan, Taiwan.
authors.forename: Jhi-Joung
authors.initials: JJ
authors.lastname: Wang
authors.affiliation: Department of Physical Medicine and Rehabilitation, Madou Sin-Lau Hospital, Tainan, Taiwan.|Department of Nursing, Chung Hwa University of Medical Technology, Tainan, Taiwan.
authors.forename: Heng-Teng
authors.initials: HT
authors.lastname: Lin
authors.affiliation: Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan, Taiwan.|Institute of Allied Health Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Ching-Hsia
authors.initials: CH
authors.lastname: Hung
mesh_terms: D000547:Amantadine / Q000008:administration & dosage*; D000775:Anesthesia, Spinal / Q000379:methods*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D007278:Injections, Spinal; D008297:Male; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D059225:Nociception / Q000187:drug effects* / Q000502:physiology; D011434:Proprioception / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000547:Amantadine
keywords: amantadine; intrathecal injection; mepivacaine; spinal anesthesia