title: The dose-dependent study of verapamil and diltiazem on spinal anesthesia in the rat.
abstract: The aim of this study evaluated the spinal anesthetic effect of verapamil and diltiazem. After rats were injected intrathecally with verapamil and diltiazem, dose-response curves were constructed. We evaluated the potency and duration of verapamil or diltiazem which compared with mepivacaine, a commonly used local anesthetic, in rats. Verapamil, diltiazem and mepivacaine produced a dose-dependent local anesthetic effect as spinal anesthesia. On a 50% effective dose (ED(50)) basis, the spinal anesthetic effect of verapamil was more potent than diltiazem or mepivacaine (P<0.01 for each comparison). On an equipotent basis (ED(25), ED(50), and ED(75)), the blockade duration of spinal anesthesia caused by diltiazem was longer than that caused by verapamil or mepivacaine (P<0.01 for each comparison). In summary, verapamil produced more potent spinal blockades, when compared with diltiazem or mepivacaine. Diltiazem demonstrated longer spinal blockades than did verapamil or mepivacaine.
authors.affiliation: Department of Physical Therapy, China Medical University, Taichung, Taiwan.
authors.forename: Yu-Wen
authors.initials: YW
authors.lastname: Chen
authors.forename: Chin-Chen
authors.initials: CC
authors.lastname: Chu
authors.forename: Yu-Chung
authors.initials: YC
authors.lastname: Chen
authors.forename: Jhi-Joung
authors.initials: JJ
authors.lastname: Wang
authors.forename: Ching-Hsia
authors.initials: CH
authors.lastname: Hung
mesh_terms: D000775:Anesthesia, Spinal / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D000818:Animals; D002121:Calcium Channel Blockers / Q000008:administration & dosage; D004110:Diltiazem / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D007278:Injections, Spinal; D008297:Male; D008619:Mepivacaine / Q000008:administration & dosage; D051381:Rats; D017207:Rats, Sprague-Dawley; D014700:Verapamil / Q000008:administration & dosage*
chemical_list: D000779:Anesthetics, Local; D002121:Calcium Channel Blockers; D008619:Mepivacaine; D014700:Verapamil; D004110:Diltiazem