BOTULINUM TOXIN TYPE A
| BOTULINUM TOXIN TYPE A (bo'tul-i-num) Botox, BOTOX Cosmetic Classifications: skeletal muscle relaxant; antispasmodic; Therapeutic: muscle relaxant; antispasmodic Pregnancy Category: C |
Availability
100 units powder for injection
Action
Botulinum toxin type A blocks neuromuscular transmission by binding to receptor sites on motor nerve terminals, entering the nerve terminals, and inhibiting the release of acetylcholine. This inhibition occurs as the neurotoxin splits a protein molecule integral to the successful docking and releasing of acetylcholine from storage areas located within nerve endings.
Therapeutic Effect
When injected intramuscularly at therapeutic doses, botulinum toxin type A produces partial chemical denervation of the muscle resulting in a localized reduction in muscle activity.
Uses
Treatment of blepharospasm, cervical dystonia, strabismus, glabellar frown wrinkles, severe axillary hyperhidrosis.
Unlabeled Uses
Treatment of other types of wrinkles, migraine headache, achalasia, focal spasticity associated with cerebral palsy with concurrent equinus gait, spasticity associated with stroke.
Contraindications
Presence of infection at the proposed injection site(s); hypersensitivity to Botox. Patients with dysphagia or respiratory compromise; pregnancy (category C).
Cautious Use
Hypersensitivity to albumin; individuals with peripheral motor neuropathic diseases (e.g., amyotrophic lateral sclerosis, or motor neuropathy), or neuromuscular junctional disorders (e.g., myasthenia gravis or Lambert-Eaton syndrome); neuromuscular disorders; ocular disease; cardiovascular disease; elderly; inflammation at the proposed injection site; weakness in the target muscle(s), lactation.
Route & Dosage
| Blepharospasm Adult/Child (>12 y): Intradermal 1.25–2.5 U injected at each site, may repeat in 3 mo if needed; cumulative dose should not exceed 200 U in a 30-d period Cervical Dystonia Adult/Adolescent (>16 y): IM 198–300 U divided among affected muscles Frown Wrinkles Adult: IM 25 U divided among affected muscles in 5 step doses, may repeat in 3–4 mo if needed Other Wrinkles Adult: SC 1–2 U per site Spasticity Adult: IM 20–50 U per affected site Child (2–18 y): IM 4 U/kg (max: 200 U per treatment) every 3 mo Axillary Hyperhidrosis Adult: IM 50 U per site, may repeat in 4 mo |
Administration
Intramuscular, Intradermal, Subcutaneous- Slowly inject required amount of nonpreserved NS (see dilution calculation) into vial. Discard vial if a vacuum does not pull diluent into vial. Gently rotate to mix. Discard if not clear, colorless, and free of particulate matter. Dilution calculation: add 1, 2, 4, or 6 mL of NS to yield, respectively, 10 U/0.1 mL, 5 U/0.1 mL, 2.5 U/0.1 mL, 1.25 U/0.1 mL.
- Note: Injection intervals of BOTOX® Cosmetic should be at least 3 mo apart.
- Store at 2°–8° C (36°–46° F) (refrigerated). Administer within 4 h of reconstitution.
INCOMPATIBILITIES Do not mix with other solutions/additives.
Adverse Effects (≥1%)
Body as a Whole: Injection site reactions (localized pain, tenderness, bruising), neck pain, flu-like symptoms, hypertonia, asthenia, fever. CNS: Headache, drowsiness. GI: Dysphagia, dry mouth, fever, nausea, vomiting. Hematologic: Ecchymosis. Musculoskeletal: Local muscle weakness, dysarthria. Respiratory: Cough, rhinitis, upper respiratory infection. Special Senses: Ptosis, superficial punctate keratitis, dry eyes, ocular irritation, lacrimation, photophobia, keratitis, diplopia.Interactions
Drug: aminoglycosides, neuromuscular blocking agents may potentiate neuromuscular blockade; chloroquine may antagonize blocking effects.Nursing Implications
Assessment & Drug Effects
- Evaluate for therapeutic effectiveness, maximal at about 1–2 wk (lasting 3–4 mo).
Patient & Family Education
- Inform physician about all prescription, nonprescription, and herbal drugs being taken.
- Report immediately any of the following: difficulty breathing or swallowing, problem with speech; unusual bleeding, bruising, or swelling around injection site.
- Note: Effects of the injection generally last 3–4 mo and then repeat treatments may be given.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug