Myobloc® Generic Name: RimabotulinumtoxinB Drug Class: Botulinum Toxins Overview Myobloc® is an injectable form of botulinum toxin type B, derived from Clostridium botulinum. It is primarily indicated for the treatment of cervical dystonia, a condition characterized by involuntary, severe neck muscle contractions. Myobloc works by inhibiting the release of acetylcholine at the neuromuscular junction, leading to a temporary reduction in muscle activity. Clinical Use Indication: Cervical dystonia (spasmodic torticollis) Mechanism of Action: Blocks presynaptic acetylcholine release, resulting in localized muscle relaxation Dosage & Administration Initial Dose (Experienced Patients): 2,500 to 5,000 Units, divided among affected muscles Initial Dose (New Patients): A lower starting dose is recommended Route: Intramuscular injection Dosage should be tailored based on muscle involvement, severity of symptoms, and patient history with botulinum toxins. Common Side Effects Injection site reactions (pain, redness, bruising, infection) Headache Dry mouth Nausea or upset stomach Joint or back pain Neck pain or stiffness Fever, flu-like symptoms Cough, sore throat Dizziness or drowsiness Anxiety Serious Side Effects – Seek Immediate Medical Attention Allergic reactions: hives, difficulty breathing, facial or throat swelling Severe muscle weakness, including areas not injected Hoarseness, drooping eyelids, blurred or double vision Trouble swallowing or speaking Chest pain, palpitations, or irregular heartbeat Sudden vision changes or eye pain Confusion, slurred speech, loss of coordination, tremors, or very stiff muscles Drug Interactions Myobloc may interact with: Other botulinum toxin products Muscle relaxants Anticholinergic medications Drugs affecting neuromuscular transmission Always inform your healthcare provider of all medications and supplements you're taking. Use in Pregnancy & Breastfeeding Pregnancy: Use only if clearly needed. Cosmetic use is not recommended during pregnancy. Breastfeeding: It is not known whether Myobloc is excreted in human milk. Consult your physician before breastfeeding. Note: This is not a complete list of all possible side effects or drug interactions. Always consult your healthcare provider for personalized medical advice.
