Muscle spasms:

Indications for MYOBLOC:

Cervical dystonia, to reduce severity of abnormal head position and neck pain. Chronic sialorrhea.


Should be administered and managed by experienced physicians. Individualize. Cervical dystonia (treatment-experienced): initially 2500–5000 Units divided among affected muscles; (treatment-naïve): use lower initial dose. Sialorrhea: 1500–3500 Units divided among the parotid (500–1500 Units/gland) and submandibular (250 Units/gland) glands. May repeat treatments no sooner than every 12 weeks. Both: adjust subsequent doses based on response.


Not established.


Infection at proposed inj site.

Boxed Warning:

Distant spread of toxin effect.


Not interchangeable with other botulinum toxin products. Risk of distant spread of toxin effect (esp. in children treated for spasticity); see full labeling. Pre-existing dysphagia or breathing difficulties. Neuromuscular disorders (eg, myasthenia gravis, ALS, Lambert-Eaton syndrome); monitor closely. Compromised respiratory function; monitor. Contains human albumin; monitor for possible viral disease or Creutzfeldt-Jakob disease transmission. Pregnancy. Nursing mothers.

Pharmacologic Class:

Neuromuscular blocker.


May be potentiated by aminoglycosides or other agents interfering with neuromuscular transmission (eg, curare-like compounds). May potentiate anticholinergic effects with concomitant anticholinergic drugs. Concomitant other botulinum toxin products or muscle relaxants may potentiate neuromuscular weakness.

Adverse Reactions:

Dry mouth, dysphagia (may be severe), inj site pain, headache; hypersensitivity reactions (discontinue if occur), possible antibody formation.

Generic Availability:


How Supplied:

Single-use vial—1