Myung Eun Chung1, Dae Heon Song, Joo Hyun Park. 1. Department of Rehabilitation Medicine, St. Paul's Hospital, College of Medicine, Catholic University of Korea, Seoul, Korea.
Abstract
BACKGROUND: Units of available botulinum toxin preparations are not interchangeable, and the dose-conversion ratios between such preparations remain controversial. OBJECTIVE: To compare the efficacy and safety of four botulinum toxin type A preparations. MATERIALS AND METHODS: Murine gastrocnemius compound muscle action potentials (CMAPs) were recorded before and after injecting the four botulinum toxin preparations (onabotulinumtoxinA, abobotulinumtoxinA, new botulinum toxin, and incobotulinumtoxinA). RESULTS: In all preparations, CMAP amplitudes decreased until 4 days after receiving the injection and then gradually recovered. On postinjection day 84, the amplitudes returned to baseline in all groups except the high-dose groups. CMAP amplitude in the contralateral limb also decreased up to postinjection days 4 to 7 and then gradually returned to baseline by postinjection day 28. CONCLUSION: The dose-conversion ratio between onabotulinumtoxinA and abobotulinumtoxinA was determined to be 1:2.6; previous reports of 1:3 were considered too high. A dose-conversion ratio between onabotulinumtoxinA and new botulinum toxin of 1:1 was deemed appropriate. OnabotulinumtoxinA and incobotulinumtoxinA demonstrated a dose-conversion ratio of 1:1.07. The efficacy of incobotulinumtoxinA was slightly lower than that of onabotulinumtoxinA. These dose-conversion ratios are applicable solely from an efficacy standpoint and not for safety. This study was conducted in mice, so it may not translate perfectly to human applications.
BACKGROUND: Units of available botulinum toxin preparations are not interchangeable, and the dose-conversion ratios between such preparations remain controversial. OBJECTIVE: To compare the efficacy and safety of four botulinum toxin type A preparations. MATERIALS AND METHODS:Murine gastrocnemius compound muscle action potentials (CMAPs) were recorded before and after injecting the four botulinum toxin preparations (onabotulinumtoxinA, abobotulinumtoxinA, new botulinum toxin, and incobotulinumtoxinA). RESULTS: In all preparations, CMAP amplitudes decreased until 4 days after receiving the injection and then gradually recovered. On postinjection day 84, the amplitudes returned to baseline in all groups except the high-dose groups. CMAP amplitude in the contralateral limb also decreased up to postinjection days 4 to 7 and then gradually returned to baseline by postinjection day 28. CONCLUSION: The dose-conversion ratio between onabotulinumtoxinA and abobotulinumtoxinA was determined to be 1:2.6; previous reports of 1:3 were considered too high. A dose-conversion ratio between onabotulinumtoxinA and new botulinum toxin of 1:1 was deemed appropriate. OnabotulinumtoxinA and incobotulinumtoxinA demonstrated a dose-conversion ratio of 1:1.07. The efficacy of incobotulinumtoxinA was slightly lower than that of onabotulinumtoxinA. These dose-conversion ratios are applicable solely from an efficacy standpoint and not for safety. This study was conducted in mice, so it may not translate perfectly to human applications.