Duration of efficacy increases with the repetition of botulinum toxin A injections in primary axillary hyperhidrosis: A study in 83 patients

Abstract

There appears to be an increase in the duration of efficacy of botulinum toxin A injections with the repetition of injections in patients with primary axillary hyperhidrosis. The reasons for this effect may be linked to the mechanism of action of botulinum toxin, and may improve our understanding of its pharmacologic effects.

Management of hyperhidrosis

“…Interestingly, the results of this study undermine a common concern about chronic Btx injections: the risk of immunoresistance to the neurotoxin proteins 20. This evidence of increased duration of effect with repetition of injections serves to refute fears that resistance to the neurotoxin’s effects may develop with repeated injections due to the formation of neutralizing antibodies 28,38,42. As elucidated in a study for such antibodies in Btx treatments for cervical dystonia, Jankovic et al43 explain that immunoresistance is more likely with high doses with each treatment, shorter periods between subsequent injections, and large cumulative dose 38.…”

“…While the efficacy of oxybutynin systemic therapy has been demonstrated in multiple studies,21–26 patients may find the anticholinergic side effects unacceptable 21,26. Btx injections are effective and should be considered in those patients who have failed topical and systemic therapies 1,11,20,27,29,35–38,40,41. New forms of administration of Btx may make this option more palatable for patients weary of injections,76–78 especially for those seeking treatment for axillary HH.…”

“…This evidence of increased duration of effect with repetition of injections serves to refute fears that resistance to the neurotoxin’s effects may develop with repeated injections due to the formation of neutralizing antibodies 28,38,42. As elucidated in a study for such antibodies in Btx treatments for cervical dystonia, Jankovic et al43 explain that immunoresistance is more likely with high doses with each treatment, shorter periods between subsequent injections, and large cumulative dose 38. They also explain that a high protein content of the injection may be associated with greater risk of antibody formation 38,43…”

“…As elucidated in a study for such antibodies in Btx treatments for cervical dystonia, Jankovic et al43 explain that immunoresistance is more likely with high doses with each treatment, shorter periods between subsequent injections, and large cumulative dose 38. They also explain that a high protein content of the injection may be associated with greater risk of antibody formation 38,43…”

“…However, because primary HH is a chronic condition, questions about longevity of treatment efficacy remain 37. In a French study of 83 patients with primary axillary HH, Lecouflet et al38 demonstrated increased duration of efficacy of Btx A injections with repetition. Over a period just short of 11 years, the patients were treated with 125 U of Btx A intradermal injections per axillae, and the duration of results of the first and last injections was recorded.…”