NTX, highly purified botulinum neurotoxin product, is less likely to spread

Abstract

Background: Researchers at the consumer group Public Citizen said that Botox(BTX) should carry a black box warning. They reviewed adverse event reports submitted to the FDA and found 16 deaths have been reported. Researchers at the consumer group Public Citizen said the botulinum toxin spreads inside the body causing serious problems. Object: To examine the spreads of botulinum toxins from the injected muscle, comparing the newly developed low molecular weight product NTX with BTX. Method: Either of NTX or BTX is injected into the left anterior limb muscle of ICR mouse, at a dose of 0.5–50 U/kg. In order to assess the effect of botulinum toxin, we measure the ‘traction power’ pursuing after injection. All the procedure is based on the approval of the Ethical Review Board for animal experiment. Results: The ‘traction power’ of the injected limbs shows decrement, dependent both on time course and on injected volume of toxins. The ‘traction power’ of the opposite limb decreased 2 days after injection of NTX 5 U/kg and BTX 2.5 U/kg. By the dosage of 50 U/kg, one death in BTX on the second day, the function of both anterior limbs became extinct. On the third day one mouse was dead by the NTX, but the right anterior limb was going to move in traction measurement. Discussion: Our data show that NTX is less likely to spread inside the body. Although the exact mechanism still remains unclear, this feature is a considerable advantage for the botulinum toxin therapy.