What is botulinum toxin resistance?

By Dr. Allen Foulad

Resistance to botulinum toxins (such as Botox, Dysport, Xeomin, and Jeuveau) can occur if neutralizing antibodies develop. This is noticed when a patient initially responds well to botulinum toxin for the treatment of wrinkles, but then experiences a decreased effect or no effect after subsequent treatments. It is believed that higher doses and more frequent treatments of botulinum toxin can increase the chance of forming neutralizing antibodies. However, there are reports of patients developing neutralizing antibodies even with small doses and infrequent treatments. It is also theorized that “complexing proteins” present in many botulinum toxin formulations can increase the risk of forming neutralizing antibodies.

Xeomin is marketed as being free from complexing proteins, and there is significant evidence to suggest that Xeomin is associated with decreased risk of formation of neutralizing antibodies. However, if you have already developed antibodies to one of the botulinum toxin type A drugs, there is a likelihood the antibodies will neutralize the other botulinum toxins in this same type A family. Even so, it is reasonable to try a trial of a different botulinum toxin to truly confirm the effect. There is a botulinum toxin type B drug in the United States called MyoBloc. Although this botulinum toxin is a different serotype, studies have shown many patients that have already formed antibodies to botulinum type A can quickly form antibodies to MyoBloc. In addition, MyoBloc is approved for use in cervical dystonia and not FDA approved for cosmetic use.

It should be noted that developing antibodies to botulinum toxin is infrequent. Improper placement, too low of a dose, or over-dilution can result in decreased treatment effect. It is important to be confident that your injector is skilled and using proper products in order to achieve an effective, long-lasting result.