Overview
11 DESCRIPTION LetibotulinumtoxinA-wlbg is an acetylcholine release inhibitor and a neuromuscular blocking agent. LetibotulinumtoxinA-wlbg is a 900 kDa botulinum toxin type A, produced from fermentation of Clostridium botulinum . LETYBO (letibotulinumtoxinA-wlbg) for injection is supplied as a sterile, preservative-free, white, freeze-dried powder in a single-dose vial for intramuscular use after...
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action LETYBO blocks cholinergic transmission at the neuromuscular junction by inhibiting the release of acetylcholine. When injected intramuscularly at therapeutic doses, LETYBO is internalized into the nerve terminal, translocates into the neuronal cytosol where it cleaves SNAP25, a protein necessary for synaptic membrane docking and subsequent release of acetylcholine which produces a dose dependent decrease of muscle function. Recovery of muscle function is gradual due to degradation of the neurotoxin and formation of axonal sprouts. Muscle reinnervation occurs, leading to a slow reversal of the pharmacological effects of LETYBO. 12.2 Pharmacodynamics No formal pharmacodynamic studies have been conducted with LETYBO. 12.
Indications
- 1 INDICATIONS AND USAGE LETYBO is indicated for the temporary improvement in the appearance of moderate to severe glabellar lines associated with corrugator and/or procerus muscle activity in adult patients. LETYBO is an acetylcholine release inhibitor and a neuromuscular blocking agent indicated for the temporary improvement in the appearance of moderate to severe glabellar lines associated with corrugator and/or procerus muscle activity in adult patients. ( 1 )
Common Doses
- 0.1 mL
- 1.25 mL
- 2.5 mL
- 0.5 mL
Dosage
2 DOSAGE AND ADMINISTRATION The recommended dose is 0.1 mL (4 Units) by intramuscular injection into each of five sites, for a total dose of 20 Units ( 2.2 , 2.3 ) 2.1 Important Administration Instructions The potency Units of LETYBO (letibotulinumtoxinA-wlbg) for injection are specific to the preparation and assay utilized. They are not interchangeable with other preparations of botulinum toxin products and, therefore, units of biological activity of LETYBO cannot be compared to nor converted into units of any other botulinum toxin products assessed with any other specific assay [see...
Black Box Warning
WARNING: DISTANT SPREAD OF TOXIN EFFECT The effects of all botulinum toxin products, including LETYBO, may spread from the area of injection to produce symptoms consistent with botulinum toxin effects. These symptoms have been reported hours to weeks after injection. Swallowing and breathing difficulties can be life threatening and there have been reports of death. LETYBO is not approved for the treatment of spasticity or any conditions other than glabellar lines [see Warnings and Precautions ( 5.1 )] .
Contraindications
- 4 CONTRAINDICATIONS LETYBO is contraindicated in: Patients with known hypersensitivity to any botulinum toxin preparation or to any of the components in the LETYBO formulation [see Warnings and Precautions ( 5.4 )] . The presence of infection at the proposed injection site(s). Known hypersensitivity to any botulinum toxin preparation or to any of the components in the LETYBO formulation ( 4 ) Infection at the injection site ( 4 ) 4.
Side Effects
- 6 ADVERSE REACTIONS The following serious adverse reactions are discussed in greater detail in other sections of the labeling: Spread of Toxin Effects [see Warnings and Precautions ( 5.1 )] Hypersensitivity Reactions [see Contraindications ( 4 ) and Warnings and Precautions ( 5.4 )] Cardiovascular System Adverse Reactions [see Warnings and Precautions ( 5.5 )] Increased Neuromuscular Compromise in Patients with Pre-Existing Neuromuscular Disorders [see Warnings and Precautions ( 5.6 )] Dysphagia and Dyspnea [see Warnings and Precautions ( 5.
Interactions
- 7 DRUG INTERACTIONS No drug interaction studies have been conducted with LETYBO. Certain drugs may potentiate the effects of LETYBO which may result in excessive neuromuscular weakness and heighten systemic anticholinergic effects. Use caution with concurrent use of LETYBO with the following products and monitor closely for excessive neuromuscular weakness: Aminoglycosides or other agents interfering with neuromuscular transmission Anticholinergic drugs Botulinum neurotoxin products administered as the same time or within several months of LETYBO Muscle relaxants administered before or after...