Onabotulinumtoxin A
Mechanism :
It is a neurotoxin which affects presynaptic membrane of the neuromuscular junction where it prevents calcium-dependent release of acetylcholine and produces a state of denervation.
Indication :
- Axillary hyperhidrosis
- Chronic migraine
- Glabellar lines
- Forehead lines
- Upper and lower limb spasticity
- Overactive bladder
- Strabismus and blepharospasm associated with dystonia.
- Off-label: Achalasia; Anal fissures; Raynaud phenomenon, severe, refractory to initial conventional therapy; Sialorrhea, Tardive dyskinesia.
Contraindications :
Hypersensitivity to any botulinum toxin preparation or any component of the formulation; infection at the proposed injection site
Dosing :
Benign essential blepharospasm, VII nerve disorders, cervical dystonia:
>12 years:
1.25-2.5 units in any 1 muscle.
Horizontal strabismus of 20 prism dioptres to 50 prism dioptres:
>12 years:
2.5-5 units in any 1 muscle. The maximum recommended dose as a single injection for any 1 muscle is 25 units.
Benign essential blepharospasm, VII nerve disorders, cervical dystonia:
The lowest recommended dose should be used when initiating treatment. Each treatment lasts approximately 3 months, after which the procedure can be repeated. Maximum cumulative dose of 6 units/kg, up to 200 units over 3 months.
Upper and lower limb spasticity in children with cerebral palsy:
2 to 18 years:
Start with ≤50 units/site. The lowest recommended dose should be used when initiating treatment. Each treatment lasts approximately 3 months, after which the procedure can be repeated. Maximum cumulative dose of 6 units/kg, up to 200 units over 3 months.
Urinary incontinence due to detrusor overactivity associated with a neurologic condition:
1-16 years:
12 units/kg (Maximum 300 units) injected into the detrusor muscle using 30-50 injections, sparing the trigone.
Adverse Effect :
Musculoskeletal and connective tissue disorders, dysphagia, muscular weakness, dry eye, xerostomia, nervous system disorders, seizures, diarrhea, headache, dyspnea.
Interaction :
Abobotulinumtoxin A: Onabotulinumtoxin A may enhance the adverse neuromuscular effect of Abobotulinumtoxin A.
Aminoglycosides: May enhance the neuromuscular-blocking effect of Onabotulinumtoxin A.
Anticholinergic Agents: May enhance the anticholinergic effect of Onabotulinumtoxin A.
Neuromuscular-Blocking Agents: May enhance the neuromuscular-blocking effect of Onabotulinumtoxin A.
Hepatic Dose :
No dosage adjustments are recommended.