This Article Full Text (Publish Ahead of Print[PDF]) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Google Scholar Articles by Hung, C.-H. Articles by Chen, Y.-W. PubMed PubMed Citation Articles by Hung, C.-H. Articles by Chen, Y.-W.

The Systemic Toxicity of Equipotent Proxymetacaine, Oxybuprocaine, and Bupivacaine During Continuous Intravenous Infusion in Rats

Ching-Hsia Hung, PhD^*, Kuo-Sheng Liu, PhD, Dong-Zi Shao, PhD, Kuang-I Cheng, MD, Yu-Chung Chen, MS^||, and Yu-Wen Chen, PhD^¶

From the *Department of Physical Therapy, National Cheng Kung University; Graduate Institute of Pharmaceutical Science, Chia Nan University of Pharmacy and Science; Department of Cosmetics Application and Management, Chung Hwa University of Medical Technology, Tainan; Department of Anesthesiology, Kaohsiung Medical University Chun-Ho Memorial Hospital, Kaohsiung; ||Division of Physical Therapy, Department of Physical Medicine and Rehabilitation, Cheng Hsin Rehabilitation Medical Center, Taipei; and ¶Department of Physical Therapy, China Medical University, Taichung, Taiwan.

Address correspondence and reprint requests to Yu-Wen Chen, PhD, Department of Physical Therapy, China Medical University, No. 91 Hsueh-Shih Rd., Taichung 40402, Taiwan. Address e-mail to cywhwok{at}mail.cmu.edu.tw.

Abstract

Background: Although proxymetacaine and oxybuprocaine produce topical ocular and spinal anesthesia, they have never been tested as cutaneous anesthetics. We compared cutaneous analgesia of proxymetacaine and oxybuprocaine with bupivacaine and tested their central nervous system and cardiovascular toxicity.

Methods: After blockade of cutaneous trunci muscle reflex with subcutaneous injections, we evaluated the local anesthetic effect of proxymetacaine and oxybuprocaine on cutaneous analgesia in rats. After IV infusions of equipotent doses of oxybuprocaine, proxymetacaine, and bupivacaine, we observed the onset time of seizure, apnea, and impending death and monitored mean arterial blood pressure and heart rate.

Results: Proxymetacaine and oxybuprocaine acted like bupivacaine and produced dose-related cutaneous analgesia. On a 50% effective dose basis, the ranks of potencies were proxymetacaine > oxybuprocaine > bupivacaine (P < 0.01). Under equipotent doses, the infusion times of proxymetacaine or oxybuprocaine required to cause seizure, apnea, and impending death were longer than that of bupivacaine (P < 0.05). The decrease in mean arterial blood pressure and heart rate was slower with oxybuprocaine and proxymetacaine compared with bupivacaine (P < 0.05 for the differences) at equipotent doses.

Conclusions: Oxybuprocaine and proxymetacaine were more potent at producing cutaneous anesthesia but were less potent than bupivacaine at producing central nervous system and cardiovascular toxicity.