The dose-dependent study of verapamil and diltiazem on spinal anesthesia in the rat.
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.
Chen
Yu-Wen
YW
Department of Physical Therapy, China Medical University, Taichung, Taiwan.
Chu
Chin-Chen
CC
Chen
Yu-Chung
YC
Wang
Jhi-Joung
JJ
Hung
Ching-Hsia
CH
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*
D000779:Anesthetics, Local; D002121:Calcium Channel Blockers; D008619:Mepivacaine; D014700:Verapamil; D004110:Diltiazem