• Muscle spasms

Myobloc Generic Name & Formulations

General Description

RimabotulinumtoxinB 2500 Units/0.5mL, 5000 Units/1mL, 10000 Units/2mL; soln for IM or intraglandular inj; contains human albumin; preservative-free.

Pharmacological Class

Neuromuscular blocker.

How Supplied

Single-use vial—1

Generic Availability


Myobloc Indications


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

Myobloc Dosage and Administration


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.

Myobloc Contraindications


Infection at proposed inj site.

Myobloc Boxed Warnings

Boxed Warning

Distant spread of toxin effect.

Myobloc Warnings/Precautions


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.

Myobloc Pharmacokinetics

See Literature

Myobloc Interactions


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.

Myobloc Adverse Reactions

Adverse Reactions

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

Myobloc Clinical Trials

See Literature

Myobloc Note

Not Applicable

Myobloc Patient Counseling

See Literature