Version July 2025
The effects of all botulinum toxin products, including letibotulinumtoxinA, 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. LetibotulinumtoxinA is not approved for the treatment of spasticity or any conditions other than glabellar lines.
Glabellar lines: IM: Inject 4 units into each of the 5 sites (2 injections in each corrugator muscle and 1 in the procerus muscle) for a total dose of 20 units per treatment session. Do not administer more frequently than every 3 months.
The renal dosing recommendations are based upon the best available evidence and clinical expertise. Senior Editorial Team: Bruce Mueller, PharmD, FCCP, FASN, FNKF; Jason A. Roberts, PhD, BPharm (Hons), B App Sc, FSHP, FISAC; Michael Heung, MD, MS.
Altered kidney function: IM: No dosage adjustment necessary for any degree of kidney dysfunction (no systemic absorption) (Ref).
Hemodialysis, intermittent (thrice weekly): IM: No supplemental dose or dosage adjustment necessary (no systemic absorption) (Ref).
Peritoneal dialysis: IM: No dosage adjustment necessary (no systemic absorption) (Ref).
CRRT: IM: No dosage adjustment necessary (Ref).
PIRRT (eg, sustained, low-efficiency diafiltration): IM: No dosage adjustment necessary (Ref).
There are no dosage adjustments provided in the manufacturer's labeling.
Refer to adult dosing.
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.
1% to 10%: Nervous system: Headache (2%)
<1%:
Immunologic: Antibody development
Ophthalmic: Blepharoptosis (including brow ptosis), blepharospasm
Frequency not defined:
Dermatologic: Folliculitis (injection site)
Local: Injection-site reaction (including bruising at injection site, hematoma at injection site, injection-site nodule, injection-site pruritus, pain at injection site, residual mass at injection site, swelling at injection site)
Ophthalmic: Periorbital hematoma (injection site)
Known hypersensitivity to any botulinum toxin preparation or any component of the formulation; infection at the proposed injection site(s).
Concerns related to adverse effects:
• Anaphylaxis/hypersensitivity reactions: Serious and/or immediate hypersensitivity reactions (eg, anaphylaxis, serum sickness, urticaria, soft-tissue edema, dyspnea) have occurred. If a reaction occurs, discontinue and institute immediate treatment.
• Antibody formation: Higher doses or more frequent administration may result in neutralizing antibody formation and loss of efficacy.
• Cardiovascular events: Use with caution in patients with cardiovascular disease; arrhythmia and myocardial infarction (some fatal) have been reported following administration of botulinum toxin products. Some of these patients had risk factors, including preexisting cardiovascular disease.
• Dysphagia: Treatment can result in swallowing or breathing difficulties; may occur within hours to weeks and persist for several months and require use of a feeding tube. Aspiration may result from severe dysphagia and is a particular risk when treating patients in whom swallowing or respiratory function is already compromised. Risk factors include small neck muscle mass, bilateral injections into the sternocleidomastoid muscle, or injections into the levator scapulae.
• Ophthalmic effects: Dry eye, reduced tear production, reduced blinking, and corneal disorders may occur with botulinum toxins; persistent symptoms may require ophthalmologic evaluation.
• Systemic toxicity: Distant spread of botulinum toxin beyond the site of injection has been reported. Immediate medical attention required if respiratory, speech, or swallowing difficulties appear.
Disease-related concerns:
• Neuromuscular disease: Avoid use in patients with myasthenia gravis. Use with caution in patients with peripheral motor neuropathic diseases, amyotrophic lateral sclerosis, or neuromuscular junction disorders (eg, Lambert-Eaton syndrome). Risk of adverse events, including generalized muscle weakness, diplopia, ptosis, dysphonia, dysarthria, severe dysphagia, and respiratory compromise, may be increased.
• Respiratory disease: Use extreme caution in patients with preexisting respiratory disease; treatment with botulinum toxin may weaken accessory muscles that are necessary for these patients to maintain adequate ventilation. Serious breathing difficulties, including respiratory failure, have been reported. Risk of aspiration resulting from severe dysphagia is increased in patients with decreased respiratory function.
Dosage form specific issues:
• Albumin: Product contains albumin and may carry a remote risk for transmission of viral diseases and variant Creutzfeldt-Jakob disease.
• Product interchangeability: Botulinum products (abobotulinumtoxinA, daxibotulinumtoxinA, incobotulinumtoxinA, letibotulinumtoxinA, onabotulinumtoxinA, prabotulinumtoxinA, rimabotulinumtoxinB) are not interchangeable; potency units are specific to each preparation and cannot be compared or converted to any other botulinum product.
Other warnings/precautions:
• Appropriate use: Do not inject into a blood vessel. Do not use more frequently than every 3 months.
• Injection site: Use with caution if there is inflammation or excessive weakness or atrophy at the proposed injection site(s). Use with caution in patients who have surgical alterations to the facial anatomy, marked facial asymmetry, ptosis, excessive dermatochalasis, deep dermal scarring, thick sebaceous skin, or the inability to substantially lessen glabellar lines by physically spreading them apart.
• Unapproved use: Serious adverse reactions, including excessive weakness, dysphagia, and aspiration pneumonia, including fatalities, have been reported in patients who have received injections for unapproved uses. In these cases, the reactions were not necessarily related to distant spread of toxin, but may have resulted from administration to the site of injection and/or adjacent structures; several patients had preexisting dysphagia or other significant disabilities.
Letybo: FDA approved February 2024; availability anticipated in the second or third quarter of 2024.
No
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution Reconstituted, Intramuscular:
Letybo: 100 units (1 ea) [contains albumin human]
IM: Use a 30- to 31-gauge needle to administer IM. Inject into each of the 5 sites (2 injections in each corrugator muscle and 1 injection in the mid-line procerus muscle). Ensure injected volume/dose is accurate and, where feasible, keep to a minimum. Avoid injection near the levator palpebrae superioris, particularly in patients with larger brow depressor complexes. Do not inject closer than 1 cm above the supraorbital rim or the central eyebrow. Refer to manufacturer's labeling for additional administration details.
An FDA-approved patient medication guide, which is available with the product information and as follows, must be dispensed with this medication:
Letybo: https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/761225s000lbl.pdf#page=12
Glabellar lines: Temporary improvement in the appearance of moderate to severe glabellar lines associated with corrugator and/or procerus muscle activity in adult patients.
Botulinum products are not interchangeable; potency differences may exist between the products.
None known.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Agents with Clinically Relevant Anticholinergic Effects: Botulinum Toxin-Containing Products may increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Aminoglycosides: May increase neuromuscular-blocking effects of Botulinum Toxin-Containing Products. Risk C: Monitor
Botulinum Toxin-Containing Products: May increase neuromuscular-blocking effects of Botulinum Toxin-Containing Products. Risk C: Monitor
Muscle Relaxants (Centrally Acting): May increase adverse/toxic effects of Botulinum Toxin-Containing Products. Specifically, the risk for increased muscle weakness may be enhanced. Risk C: Monitor
Neuromuscular-Blocking Agents: Botulinum Toxin-Containing Products may increase neuromuscular-blocking effects of Neuromuscular-Blocking Agents. Risk C: Monitor
Maternal toxicity and adverse effects on fetal growth were observed in animal reproduction studies following IM administration at 3 times the maximum recommended human dose.
Because data related to the use of botulinum toxins for cosmetic procedures during pregnancy are limited, use is generally avoided (Garg 2022; Morgan 2006; Trivedi 2017).
It is not known if letibotulinumtoxinA is present in breast milk.
According to the manufacturer, the decision to breastfeed during therapy should consider the risk of infant exposure, the benefits of breastfeeding to the infant, and the benefits of treatment to the mother.
Difficulty with swallowing, speaking, breathing, or muscle weakness or paralysis in areas other than the targeted area; ophthalmic effects (eg, eye dryness, eye irritation, photophobia, changes in vision).
LetibotulinumtoxinA (botulinum toxin type A) is a neurotoxin, produced by Clostridium botulinum, spore-forming anaerobic bacillus, that blocks cholinergic transmission at the neuromuscular junction and inhibits the release of acetylcholine. This inhibition occurs as the neurotoxin cleaves SNAP-25, a protein integral to the successful docking and release of acetylcholine from vesicles situated within nerve endings. There is evidence that reinnervation of the muscle may occur, thus slowly reversing muscle denervation produced by letibotulinumtoxinA.
