| Type A
There are subtypes of type A botulinum toxin, two of which (Botox and Dysport) are commonly used to treat sialorrhoea. These subtypes have different biological activities; thus, dose adjustments must be made accordingly (Botox 1:3 Dysport).46
| Type B (NeuroBloc)
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Dosing |
Commonly used doses in trials to date: 100 MU of Botox, 250 MU of Dysport, 2500 MU of NeuroBloc. Doses should be divided between the submandibular and parotid glands, with the parotid receiving a greater fraction of the total dose. Optimal therapeutic dose not established. Titrate as appropriate.49
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Delivery | US guidance
| Landmark guided
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Outcomes of treatment with botulinum toxin | Advantages50
Meta-analysis data supporting its clinical efficacy Effective in patients with symptoms resistant to medications Effects last for 3–6 months Fewer side effects than anticholinergic medication Minimally invasive May decrease risk of aspiration pneumonia in neurologically impaired children.51
| Disadvantages
Common adverse effects: xerostomia, thickened bronchial secretions and viscous saliva, difficulty chewing and pain at the site of injection. Reverse slowly as toxin effect wears off.52
Dysphagia is a rare side effect.53
Repeat injections may result in antibody formation and fading efficacy.49
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Group characteristics |
Patients with motor neurone disease may be more prone to adverse effects and shorter benefit duration compared with those with Parkinson’s disease. Old age may be associated with longer benefit duration.53
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