Table 1.

Different preparations of botulinum toxin

US generic name	Brand name	Manufacturer	Packaging Units/phial
OnabotulinumtoxinA	Botox	Allergan	50, 100, 200
AbobotulinumtoxinA	Dysport	Ipsen	300, 500
IncobotulinumtoxinA	Xeomin	Merz Pharmaceuticals	50, 100
RimabotulinumtoxinB	NeuroBloc	Eisai Ltd	2500, 5000, or 10 000

These four preparations are available and licensed in the UK for the treatment of cervical dystonia. The units between these different preparations are not equivalent, and the clinician must be vigilant when switching from one preparation to another. As an indication, 1 unit Botox=1 unit Xeomin=3 units Dysport=50 units Neurobloc for cervical dystonia.