A Bastos-Lima | PubMed Health

PubMed1997

DYSBOT: a single-blind, randomized parallel study to determine whether any differences can be detected in the efficacy and tolerability of two formulations of botulinum toxin type A--Dysport and Botox--assuming a ratio of 4:1.

BACKGROUND: Elston and Russell discovered a difference in the biological potency of the English formulation of botulinum toxin type A or BTX-A (Dysport) and the American formulation (Botox). Potency of both is expressed in LD50 mouse units, but because of assay differences, these units are not equivalent. Since the first warning by Quinn and Hallet on the clinical importance of this issue, it has been impossible to reach a consensus on the conversion factor for the potency of these formulations. OBJECTIVE: To test the hypothesis that the conversion factor for the clinical potency of Dysport to Botox is approximately 4:1. DYSBOT is an acronym that results from adding "DYS" from Dysport with "BOT" from Botox. PATIENTS AND METHODS DESIGN: A single-blind, randomized, parallel comparison. A total of 91 patients with blepharospasm or hemifacial spasm were randomized to treatment with Dysport or Botox using a fixed potency ratio of 4:1. Clinical evaluations: The patients were evaluated at baseline (day of the treatment). 1 month after treatment, and whenever the effect was judged to be fading. Objective and functional rating scales were used as quantitative measures of the change in clinical status. Adverse reactions were collected using a systematic questionnaire. RESULTS: Using this ratio between products, both Dysport and Botox groups produced similar clinical efficacy and tolerability. For patients showing a positive response without the need of a booster, the duration of effect was 13.3 +/- 5.9 weeks for the Dysport group and 11.2 +/- 5.8 weeks for the Botox group. Of 48 patients, 11 (23%) needed booster treatment in the Dysport group compared with five (12%) of 43 in Botox group. Adverse events were noted in 24 (50%) of 48 patients in the Dysport group and 20 (47%) of 43 of the Botox-treated group. CONCLUSIONS: Using a 4:1 conversion ratio for Dysport and Botox, similar results were obtained for the two treatments in an appropriately powered study, suggesting that this conversion factor is a good estimate of their comparative clinical potencies.

Aged↗

PubMed1995

The response of "de novo" Parkinson's disease patients to bromocriptine in a "low and slow" regimen is predictive for prognosis.

It is possible that Bromocriptine only determines a complete antiparkinson effect in a subset of P.D. patients that have a good dopaminergic reserve. Our study intent to demonstrate that a good short-term response to Bromocriptine used in a "low and slow" regimen is a marker of long term good prognosis. We studied a series of 36 sequential "de novo" P.D. patients treated with Bromocriptine in a "low and slow" regimen. The principal end-point was the introduction of Levodopa. "Good prognosis" was defined as no need of Levodopa until five years of follow-up. An improvement greater than 33% in the Columbia rating scale, at the 6th month of treatment, was the cut-off point to decide that a patient had a good short term response to Bromocriptine. Nine patients fulfilled the criteria for being good short term responders. Multiple regression analysis showed that this outcome could not be predicted by the clinical characteristics of the patients at admission. The sensitivity and the specificity of the short term response to Bromocriptine to predict a good prognosis were 70% and 90.5% respectively. We conclude that Bromocriptine in monotherapy is an efficient antiparkinson agent in 1/3 of "de novo" P.D. patients and good short term response to Bromocriptine is an acceptable marker for a good prognosis. Therefore it is possible that the response to Bromocriptine is a discriminator for a subset of P.D. patients in the early phases of the disease.

Adult↗