[Conversion ratio between different botulinum neuroprotein product in neurological practice]

Area of Science:

• Neurology
• Pharmacology
• Biochemistry

Background:

• Botulinum toxin type A (BTA) has been used clinically for nearly 30 years.
• Several BTA formulations exist for neurological indications, each with unique active neuroprotein content.
• The precise unit equivalence between different BTA products remains a subject of discussion.

Purpose of the Study:

• To clarify the unit ratios and potential impact on efficacy for different botulinum toxin type A products.
• To provide evidence-based guidance on BTA unit conversion for clinical practice.

Main Methods:

• Review of clinical guidelines, systematic reviews, and high-quality research.
• Analysis of scientific publications on BTA equivalence doses.
• Comparison of active neuroprotein content across different BTA formulations.

Main Results:

• The unit of activity for each BTA is unique and not directly comparable.
• Scientific literature shows a wide range of reported equivalence ratios between onabotulinumtoxin A (Botox) and abobotulinumtoxin A (Dysport).
• Current clinical guidelines and high-quality evidence suggest a Dysport to Botox ratio of 3(2.5):1 for dose conversion.

Conclusions:

• Differences in active neuroprotein content and units necessitate careful consideration when switching between BTA products.
• A fixed ratio is recommended only when switching drugs or if access to a specific drug is limited.
• Botulinum toxin type A remains a first-line therapy for several neurological conditions, with established efficacy and safety profiles for commonly used brands like Botox, Dysport, and Xeomin.