Botulinum toxin
BOTOX
What it isSNARE-cleaving blocker of acetylcholine release; dystonia, spasticity, chronic migraine, overactive bladder, hyperhidrosis, cosmesis.
Why this oneLocal injection produces prolonged, reversible chemodenervation with little systemic exposure.
What limits itDistant spread can cause dysphagia or respiratory weakness; potency units are not interchangeable across products.
Pearls
- Migraine: chronic only, not episodic; 155 units every 12 weeks.
- OAB: intradetrusor after anticholinergic failure; retention and UTI common.
- OAB onset about 2 weeks; effect lasts 3–12 months.
- Off-label injections help postherpetic, diabetic and trigeminal neuropathic pain.
FDA-approved for
- dystonia/spasticity/migraine/cosmetic (1989)
Classes and tags
Clinical profile
Legacy pregnancy categoryUnknown / historical label unavailable
Defining liabilityDistant toxin spread can cause dysphagia, generalized weakness and respiratory compromise.
FDA label
Read the full label on DailyMed ↗
BOXED WARNING Distant spread of toxin effect — BOTOX and all botulinum toxin products may spread beyond the injection site (asthenia, generalized weakness, diplopia, ptosis, dysphagia, dysphonia, dysarthria, urinary incontinence, breathing difficulty) hours to weeks after injection; swallowing/breathing difficulty can be life threatening and deaths reported. Risk probably greatest in children treated for spasticity; also adults, esp. with predisposing conditions; reported at doses comparable to or lower than cervical dystonia/spasticity doses.
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Overactive bladder (urge incontinence, urgency, frequency; anticholinergic failure/intolerance) | Adults | 100 Units intradetrusor (100 Units/10 mL): 20 × 0.5 mL (5 Units) injections ~1 cm apart via cystoscope, avoiding trigone | 100 Units per treatment; reinject when effect diminishes | 100 Units per treatment (maximum recommended); no sooner than 12 weeks after prior bladder injection |
| Urinary incontinence due to neurologic detrusor overactivity (e.g., SCI, MS) | Adults | 200 Units intradetrusor (200 Units/30 mL): 30 × 1 mL (~6.7 Units) injections ~1 cm apart, avoiding trigone | 200 Units per treatment | 200 Units per treatment (do not exceed); no sooner than 12 weeks after prior bladder injection |
| Chronic migraine prophylaxis (≥15 headache days/month) | Adults | 155 Units IM as 0.1 mL (5 Units) × 31 sites across 7 head/neck areas (30-gauge needle) | 155 Units every 12 weeks | 155 Units per session (recommended dose); adult cumulative ≤400 Units per 3 months |
| Upper limb spasticity | Adults | Lowest recommended dose; IM divided among affected muscles (trials 75–400 Units/session); ≤50 Units per site generally | Up to 400 Units per session, per-muscle dosing (e.g., biceps 60–200 Units) | 400 Units cumulative per 3 months (all indications); repeat generally no sooner than 12 weeks |
| Lower limb spasticity | Adults | 300–400 Units IM divided among 5 muscles (gastrocnemius, soleus, tibialis posterior, FHL, FDL) | 300–400 Units per session | 400 Units cumulative per 3 months; repeat generally no sooner than 12 weeks |
| Cervical dystonia | Adults | Individualized IM, divided among affected muscles; lower initial dose if BOTOX-naïve | Individualized (study mean 236 Units; 25th–75th percentile 198–300 Units) | ≤100 Units into sternocleidomastoid (dysphagia); ≤50 Units per site generally; 400 Units cumulative per 3 months |
| Severe primary axillary hyperhidrosis (inadequate on topicals) | Adults | 50 Units intradermal per axilla (100 Units/4 mL; 2 mL in 0.1–0.2 mL aliquots at 10–15 sites, 1–2 cm apart) | 50 Units per axilla; repeat when effect diminishes | Undefined per indication; adult cumulative ≤400 Units per 3 months |
| Blepharospasm (dystonia-associated) | ≥12 y | 1.25–2.5 Units IM (0.05–0.1 mL) into each of 3 sites per involved eye (upper-lid medial/lateral, lower-lid lateral pre-tarsal orbicularis oculi) | May increase up to two-fold at repeat sessions (~every 3 months) if response insufficient; little benefit >5 Units per site | 200 Units cumulative per 30 days |
| Strabismus | ≥12 y | EMG-guided into extraocular muscle (0.05–0.15 mL): vertical or horizontal <20 prism diopters 1.25–2.5 Units/muscle; horizontal 20–50 prism diopters 2.5–5 Units/muscle; VI nerve palsy ≥1 month 1.25–2.5 Units medial rectus | Repeat dose comparable to initial; up to two-fold if paralysis incomplete | 25 Units as a single injection for any one muscle |
| Neurogenic detrusor overactivity (anticholinergic failure/intolerance) | Pediatric ≥5 y | ≥34 kg: 200 Units intradetrusor; <34 kg: 6 Units/kg (12–<14 kg 72 Units … 32–<34 kg 192 Units); 20 × 0.5 mL injections (10 mL total) | Same per treatment; reinject when effect diminishes | 200 Units (≥34 kg) or 6 Units/kg (<34 kg) per treatment; no sooner than 12 weeks after prior bladder injection |
| Upper limb spasticity | Pediatric ≥2 y | 3–6 Units/kg IM divided among affected muscles | 3–6 Units/kg per session | Per session lower of 6 Units/kg or 200 Units; total lower of 10 Units/kg or 340 Units per 3 months |
| Lower limb spasticity | Pediatric ≥2 y | 4–8 Units/kg IM divided among affected muscles (gastrocnemius, soleus, tibialis posterior) | 4–8 Units/kg per session | Per session lower of 8 Units/kg or 300 Units; total lower of 10 Units/kg or 340 Units per 3 months |
Titration Adjust only at repeat sessions: bladder no sooner than 12 weeks; spasticity generally ≥12 weeks; blepharospasm ~3 months (up to two-fold); strabismus once prior effect has dissipated (re-examine 7–14 days).
Renal Undefined
Hepatic Undefined
Cumulative cap across all indications in a 3-month interval: adults 400 Units; pediatrics lower of 10 Units/kg or 340 Units. Start at the lowest recommended dose.
Instructions
- Routes are indication-specific: IM (migraine, spasticity, cervical dystonia, blepharospasm, strabismus), intradetrusor via cystoscope (bladder), intradermal (axillary hyperhidrosis).
- Units are specific to BOTOX and NOT interchangeable with any other botulinum toxin product — do not convert doses.
- Reconstitute only with preservative-free 0.9% Sodium Chloride Injection, USP. 100 Unit vial + 1/2/4/8/10 mL → 10/5/2.5/1.25/1 Units per 0.1 mL; 200 Unit vial + 1/2/4/8/10 mL → 20/10/5/2.5/2 Units per 0.1 mL.
- Inject diluent slowly; discard vial if vacuum does not pull diluent in; mix by gently rotating; must be clear, colorless, particle-free.
- Administer within 24 hours after reconstitution; store reconstituted product refrigerated (2° to 8°C) until use. Bladder doses diluted in syringe: use immediately.
- Single-dose vials; discard unused portion. Unopened vials: refrigerate 2° to 8°C.
- Intradetrusor: no UTI at treatment; prophylactic antibiotics (not aminoglycosides) 1-3 days before, day of, and 1-3 days after; stop antiplatelets ≥3 days before; observe ≥30 minutes post-injection.
- Spasticity/strabismus: EMG guidance (strabismus requires EMG or surgical exposure); localization by EMG, nerve stimulation or ultrasound recommended for spasticity.
Available strengths
- inj 300, 500 units
Contraindications
- Infection at the proposed injection site(s)
- Intradetrusor injection with urinary tract infection, or urinary retention / PVR >200 mL in patients not routinely performing clean intermittent self-catheterization
Cautions
- Spread of toxin effect (swallowing, speech, breathing difficulty — seek immediate care)
- Units not interchangeable with other botulinum toxin products
- Serious adverse reactions with unapproved use
- Hypersensitivity reactions (anaphylaxis, serum sickness, urticaria, edema, dyspnea)
- Pre-existing neuromuscular disorders (ALS, myasthenia gravis, Lambert-Eaton) — increased risk
- Dysphagia and breathing difficulties
- Pulmonary effects in compromised respiratory status (spasticity, neurologic detrusor overactivity)
- Corneal exposure/ulceration (blepharospasm)
- Retrobulbar hemorrhage (strabismus)
- Bronchitis and URTI (spasticity)
- Autonomic dysreflexia (neurologic detrusor overactivity)
- UTI (overactive bladder)
- Urinary retention after bladder treatment — monitor PVR if not catheterizing
Adverse reactions
- OAB: UTI, dysuria, urinary retention
- Adult neurologic detrusor overactivity: UTI, urinary retention
- Pediatric neurologic detrusor overactivity: UTI, leukocyturia, bacteriuria
- Chronic migraine: neck pain, headache
- Adult spasticity: pain in extremity
- Pediatric spasticity: upper respiratory tract infection
- Cervical dystonia: dysphagia, URI, neck pain, headache, increased cough, flu syndrome, back pain, rhinitis
- Axillary hyperhidrosis: injection site pain and hemorrhage, non-axillary sweating, pharyngitis, flu syndrome
Pregnancy No adequate human data; in animals, BOTOX in pregnancy reduced fetal weight and skeletal ossification at clinically relevant doses associated with maternal toxicity.
Lactation No data on presence in human or animal milk or effects on the breastfed infant or milk production; weigh breastfeeding benefits against maternal need.
Cost
Botulinum toxin (BOTOX)
| Strength | #/mo | generic $/unit | CostPlus | |
|---|---|---|---|---|
| 300 units | inj | per unit | not offered | |
| 500 units | inj | per unit | not offered |
NADAC is a voluntary CMS survey of what retail community pharmacies pay for the drugs they stock. Botulinum toxin is administered under clinical supervision and dispensed outside retail pharmacies, so it rarely appears on surveyed invoices.
Generic entryNo US generic
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Self-check
- Are botulinum toxin potency units interchangeable across products?
No. - What can distant toxin spread cause?
Dysphagia or respiratory weakness.