# Strength Units in Botulinum Toxin Medicinal Products **URL:** \ **Category:** Drugs Extension User Group\ **Created:** [March 11, 2026, 9:15pm UTC](https://forums.snomed.org/t/strength-units-in-botulinum-toxin-medicinal-products/1066 "2026-03-11T21:15:09Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![sbyrnes](https://dub1.discourse-cdn.com/flex014/user_avatar/forums.snomed.org/sbyrnes/32/447_2.png) [@sbyrnes](https://forums.snomed.org/u/sbyrnes)\ **Post date:** [March 11, 2026, 9:15pm UTC](https://forums.snomed.org/t/strength-units-in-botulinum-toxin-medicinal-products/1066/1 "2026-03-11T21:15:09Z")
Hi All, We are currently looking at botulinum toxin products in Ireland and wondering how people manage the product/brand specific units for these products in the extension level? These products typically include a statement in the SmPC that the units are product specific and non-interchangeable with other botulinum toxin units. By default we would not include any proprietary dose forms, units of presentation etc. but these are treated slightly differently by the EMA referential database, which does recognise these product specific units (‘speywood units’ and ‘allergan units’ based on the products available in Ireland) Including them where mentioned by the product literature would then create a situation where some _real clinical drugs_ would get their own _clinical drug_, while multiple other brands would classify under a different _clinical drug._ | Product | SmPC contains statement on non-interchangeability of units | Units specified | Units recognised in EMA RMS | | --- | --- | --- | --- | | | | | | | Alluzience, 200 Speywood units / mL, solution for injection | Yes | Speywood Units | Yes | | Azzalure, 125 Speywood units, powder for solution for injection | Yes | Speywood units | Yes | | BOCOUTURE 100 units powder for solution for injection | Yes | Units | Yes | | BOTOX 100 Allergan Units powder for solution for injection | Yes | Allergan Units | Yes | | BOTOX 200 Allergan Units powder for solution for injection | Yes | Allergan Units | Yes | | BOTOX 50 Allergan Units powder for solution for injection | Yes | Allergan Units | Yes | | Dysport 300 units Powder for solution for injection | Yes | Units | Yes | | Dysport 500 units Powder for solution for injection | Yes | Units | Yes | | Letybo 50 units powder for solution for injection | Yes | Units | Yes | | Nuceiva 100 U Powder for solution for injection | Yes | Units | Yes | | Nuceiva 50 U Powder for solution for injection | Yes | Units | Yes | | Relfydess, 100 units / mL, solution for injection | Yes | Units | Yes | | VISTABEL, 4 Allergan Units / 0.1ml, Powder for solution for injection | Yes | Allergan Units | Yes | | XEOMIN 200 units powder for solution for injection | Yes | Units | Yes | | XEOMIN 50 units powder for solution for injection | Yes | Units | Yes | Thanks, Shane ---
**Author:** ![rlindstrom](https://avatars.discourse-cdn.com/v4/letter/r/74df32/32.png) [@rlindstrom](https://forums.snomed.org/u/rlindstrom)\ **Post date:** [March 12, 2026, 1:48pm UTC](https://forums.snomed.org/t/strength-units-in-botulinum-toxin-medicinal-products/1066/2 "2026-03-12T13:48:12Z")
In crossborder services, we have mapped all the quirky special units to UCUM arbitrary unit [arb’U] which maps to 258766007 |Arbitrary unit|. Not sure if this technical workaround is sufficient for anything. It would still keep them separated from normal units, but at least you don’t have a different unit for every funky unit manufacturers come up with. It’s also fair to have them as separate clinical drugs, because they imply they are different: unmeasurable with the same units, so effectively uncomparable. ---
**Author:** ![mcordell](https://dub1.discourse-cdn.com/flex014/user_avatar/forums.snomed.org/mcordell/32/325_2.png) [@mcordell](https://forums.snomed.org/u/mcordell)\ **Post date:** [March 13, 2026, 6:33am UTC](https://forums.snomed.org/t/strength-units-in-botulinum-toxin-medicinal-products/1066/3 "2026-03-13T06:33:25Z")
In AMT all\* our products are modelled using “mouse LD50 units”, but the preferred terms simply use the word “unit”. (\*Two are modelled with the “arbitrary unit”) - this was on advice from our user group as to their preference. While we might have the same unit, the specific ingredients do vary (e.g. letibotulinumtoxinA vs daxibotulinumtoxinA) - so that contributes to the decision if the products are interchangeable - but that is something third parties determine (not AMT modelling). In general even if the ingredients and units are the same for a product - that doesn’t necessarily imply interchangability (though often it is). | Concept Id | Preferred Term | Fully Specified Name | | --- | --- | --- | | 720851000168109 | Botox 100 units powder for injection, 100 units vial | Botox (botulinum toxin type A 100 mouse LD50 units) powder for injection, 100 mouse LD50 units vial (branded clinical drug) | | 720941000168103 | Botox 200 units powder for injection, 200 units vial | Botox (botulinum toxin type A 200 mouse LD50 units) powder for injection, 200 mouse LD50 units vial (branded clinical drug) | | 880731000168103 | Botox 50 units powder for injection, 50 units vial | Botox (botulinum toxin type A 50 mouse LD50 units) powder for injection, 50 mouse LD50 units vial (branded clinical drug) | | 933448511000036103 | Daxxify 100 units powder for injection, 100 units vial | Daxxify (daxibotulinumtoxinA 100 units) powder for injection, 100 units vial (branded clinical drug) | | 1209721000168101 | Dysport 125 units powder for injection, 125 units vial | Dysport (clostridium botulinum type A toxin-haemagglutinin complex 125 mouse LD50 units) powder for injection, 125 mouse LD50 units vial (branded clinical drug) | | 721091000168101 | Dysport 300 units powder for injection, 300 units vial | Dysport (clostridium botulinum type A toxin-haemagglutinin complex 300 mouse LD50 units) powder for injection, 300 mouse LD50 units vial (branded clinical drug) | | 721021000168103 | Dysport 500 units powder for injection, 500 units vial | Dysport (clostridium botulinum type A toxin-haemagglutinin complex 500 mouse LD50 units) powder for injection, 500 mouse LD50 units vial (branded clinical drug) | | 1679111000168101 | Letybo 100 units powder for injection, 100 units vial | Letybo (letibotulinumtoxinA 100 mouse LD50 units) powder for injection, 100 mouse LD50 units vial (branded clinical drug) | | 1679061000168102 | Letybo 50 units powder for injection, 50 units vial | Letybo (letibotulinumtoxinA 50 mouse LD50 units) powder for injection, 50 mouse LD50 units vial (branded clinical drug) | | 1675151000168103 | Nuceiva 100 units powder for injection, 100 units vial | Nuceiva (prabotulinumtoxinA 100 mouse LD50 units) powder for injection, 100 mouse LD50 units vial (branded clinical drug) | | 933310741000036108 | Relfydess 150 units/1.5 mL injection, 1.5 mL vial | Relfydess (relabotulinumtoxinA 150 units / 1.5 mL) injection, 1.5 mL vial (branded clinical drug) | | 682751000168100 | Xeomin 100 units powder for injection, 100 units vial | Xeomin (incobotulinumtoxinA 100 mouse LD50 units) powder for injection, 100 mouse LD50 units vial (branded clinical drug) | | 173581000036107 | Xeomin 50 units powder for injection, 50 units vial | Xeomin (incobotulinumtoxinA 50 mouse LD50 units) powder for injection, 50 mouse LD50 units vial (branded clinical drug) |