Hence, variations in species sensitivities to diverse botulinum neurotoxin serotypes preclude extrapolation of animal dose-activity interactions to human dose estimates. The precise action of MYOBLOC (botulinum toxin type b) ranges among 70 to a hundred thirty Units/ng. Extreme Allergic Reactions. Myobloc may lead to allergic reactions, which may be severe. https://myoblocinjection68912.sharebyblog.com/35288531/myobloc-for-dummies