Excessive weak spot could also be exaggerated by administration of the muscle mass relaxant prior to or just after administration of MYOBLOC. Extreme Allergic Reactions. Myobloc may lead to allergic reactions, that may be severe. Quit applying Myobloc and get aid instantly if you have any of the following signs https://lorenzofnpqp.thezenweb.com/new-step-by-step-map-for-myobloc-73590154