title: What is the optimum dose of type A botulinum toxin for treating neurogenic bladder overactivity?
abstract: OBJECTIVE
  To assess the effects of two doses of botulinum toxin A (Dysport, Ipsen-Biotech, France; 500 and 1000 Speywood units, SU) injected into the bladder for treating incontinence due to a neurogenic overactive bladder.
  
  
  METHODS
  In an open-label, prospective study between October 2002 and May 2004, in two centres, we analysed the effects of successive doses of 500 and 1000 SU of Dysport, endoscopically injected into the detrusor muscle. At each step, patients (26 women and 19 men) were re-evaluated at 1 month (clinical evaluation and pressure-flow study). If there was a 'good' clinical response (complete absence of urinary leakage) the patient was observed until incontinence recurred; otherwise a further injection was administered at a higher dose.
  
  
  RESULTS
  The mean (sd, range) follow-up was 22 (0.75, 5-31) months; 11 of the 45 patients (24%) did not respond primarily at 1 month for both doses. The analysis of the two curves of survival with no re-injection of Dysport showed a statistically longer action at 1000 SU (P = 0.016). However, in this group there was one patient with general muscle weakness and asthenia, which could have been related to the injection.
  
  
  CONCLUSIONS
  The optimum dose of Dysport for incontinence secondary to a neurogenic overactive bladder is not yet defined; 1000 SU probably has a more prolonged effect than 500 SU but exposes the patient to major complications. Further studies evaluating the clinical effect of 750 SU of Dysport are necessary.
authors.affiliation: Hôpital Henry Gabrielle, Saint Genis Laval, and Hôpital Charles Nicolle, Rouens, France. alain.ruffion@chu-lyon.fr
authors.forename: Alain
authors.initials: A
authors.lastname: Ruffion
authors.forename: Olivier
authors.initials: O
authors.lastname: Capelle
authors.forename: Philippe
authors.initials: P
authors.lastname: Paparel
authors.forename: Beatrice
authors.initials: B
authors.lastname: Leriche
authors.forename: Albert
authors.initials: A
authors.lastname: Leriche
authors.forename: Philippe
authors.initials: P
authors.lastname: Grise
mesh_terms: D019274:Botulinum Toxins, Type A / Q000008:administration & dosage* / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D009465:Neuromuscular Agents / Q000008:administration & dosage* / Q000009:adverse effects; D001750:Urinary Bladder, Neurogenic / Q000188:drug therapy* / Q000209:etiology; D014549:Urinary Incontinence / Q000188:drug therapy* / Q000209:etiology
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A