Botulinum toxin A for the treatment of delayed gastric emptying

Observational data suggest that intrapyloric injection of botulinum toxin A (BoTN/A) reduces symptoms and accelerates gastric emptying in idiopathic and diabetic gastroparesis. Our purpose was to determine whether botulinum toxin improves symptoms to a significantly greater extent than placebo. An additional objective was to determine whether there is an acceleration of gastric emptying after injection.

A single-institution, randomized, double-blind, placebo-controlled trial* was done. Eligible patients had a Gastroparesis Cardinal Symptom Index score > or = 27 with randomization to intrapyloric botulinum toxin, 200 U (units), or saline placebo. Reassessment of symptoms and repeat gastric emptying scan at 1-month follow-up were done.

Thirty-two patients were randomized to botulinum toxin (N = 16) and placebo (N = 16). At 1-month follow-up, 37.5% randomized to botulinum toxin and 56.3% randomized to placebo achieved improvement as defined by this study. There were no identifiable clinical predictors of response. The botulinum toxin group demonstrated improvement in gastric emptying; however, this was not superior to placebo. No serious adverse events were attributable to botulinum toxin.

Intrapyloric injection of botulinum toxin improves gastric emptying in patients with gastroparesis, although this benefit was not superior to placebo at 1 month. Also, in comparison to placebo, symptoms do not improve significantly by 1 month after injection. Overall, we are unable to recommend botulinum toxin therapy for widespread use in the treatment of delayed gastric emptying until more data are available.