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Myobloc Side Effects

Generic name: rimabotulinumtoxinB

Medically reviewed by Drugs.com. Last updated on Jul 20, 2023.

Note: This document contains side effect information about rimabotulinumtoxinB. Some dosage forms listed on this page may not apply to the brand name Myobloc.

Applies to rimabotulinumtoxinB: intramuscular solution.

Warning

Intramuscular route (Injectable)

Postmarketing reports indicate that the effects of rimabotulinumtoxinB and all botulinum toxin products may spread from the area of injection to produce symptoms consistent with botulinum toxin effects. These may include asthenia, generalized muscle weakness, diplopia, blurred vision, ptosis, dysphagia, dysphonia, dysarthria, urinary incontinence, and breathing difficulties. These symptoms have been reported hours to weeks after injection. Swallowing and breathing difficulties can be life threatening and there have been reports of death. The risk of symptoms is probably greatest in children treated for spasticity but symptoms can also occur in adults treated for spasticity and other conditions, particularly in those patients who have underlying conditions that would predispose them to these symptoms. In unapproved uses, including spasticity in children and adults, and in approved indications, cases of spread of effect have occurred at doses comparable to those used to treat cervical dystonia and at lower doses.

Serious side effects of Myobloc

Along with its needed effects, rimabotulinumtoxinB (the active ingredient contained in Myobloc) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking rimabotulinumtoxinB:

More common

Rare

Incidence not known

Other side effects of Myobloc

Some side effects of rimabotulinumtoxinB may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Other side effects of Myobloc

Some side effects of rimabotulinumtoxinB may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For Healthcare Professionals

Applies to rimabotulinumtoxinB: injectable solution, intramuscular solution.

General

The most commonly reported adverse events have included dry mouth, dysphagia, dyspepsia, and injection site pain.[Ref]

Gastrointestinal

Most case reports of dry mouth or dysphagia were reported as mild or moderate, however, these were the most frequent adverse events resulting in treatment discontinuation. An increased incidence of dysphagia occurred with an increased dose in the sternocleidomastoid muscle; an increasing incidence of dry mouth was associated with dose-related increases in doses injected into the splenius capitis, trapezius, and sternocleidomastoid muscles.

Gastrointestinal disorder, vomiting, glossitis, stomatitis, and tooth disorder were reported in greater than 2% of patients.[Ref]

Very common (10% or more): Dry mouth (up to 39%), dysphagia (up to 25%)

Common (1% to 10%): Dyspepsia, nausea, dental carries

Frequency not reported: Gastrointestinal disorder, vomiting, glossitis, stomatitis, tooth disorder

Postmarketing reports: Constipation[Ref]

Respiratory

Common (1% to 10%): Increased cough, rhinitis, dysphonia

Frequency not reported: Dyspnea, lung disorder, pneumonia

Postmarketing reports: Aspiration pneumonia[Ref]

Dyspnea, lung disorder, and pneumonia were reported in greater than 2% of patients.[Ref]

Cardiovascular

Frequency not reported: Peripheral edema, edema, chest pain, vasodilation[Ref]

Chest pain, vasodilation, peripheral edema, and edema were reported in greater than 2% of patients.[Ref]

Local

Very common (10% or more): Injection site pain (up to 15%)[Ref]

Musculoskeletal

Common (1% to 10%): Arthralgia, back pain

Frequency not reported: Arthritis, joint disorder

Postmarketing reports: Exaggerated muscle weakness[Ref]

Arthritis and joint disorder were reported in greater than 2% of patients.[Ref]

Ocular

Common (1% to 10%): Blurred vision

Postmarketing reports: Abnormal accommodation, ptosis, dry eye, accomodation disorder[Ref]

Hypersensitivity

Frequency not reported: Allergic reaction[Ref]

Allergic reaction was reported in greater than 2% of patients.[Ref]

Nervous system

Very common (10% or more): Headache (up to 11%)

Common (1% to 10%): Torticollis, myasthenia, dizziness

Frequency not reported: Migraine, hyperesthesia, somnolence, taste perversion[Ref]

Migraine, hyperesthesia, somnolence, and taste perversion were reported in greater than 2% of patients.[Ref]

Dermatologic

Frequency not reported: Cyst, pruritus, ecchymosis

Postmarketing reports: Angioedema, urticaria, rash[Ref]

Cyst, ecchymosis, and pruritus was reported in greater than 2% of patients.[Ref]

Immunologic

Very common (10% or more): Infection (up to 15%)

Common (1% to 10%): Flu syndrome

Frequency not reported: Viral infection, antibodies against botulinum toxin b[Ref]

Viral infection and antibodies against botulinum toxin b were reported in greater than 2% of patients.[Ref]

Metabolic

Frequency not reported: Hypercholesterolemia[Ref]

Hypercholesterolemia was reported in greater than 2% of patients.[Ref]

Psychiatric

Frequency not reported: Anxiety, confusion[Ref]

Anxiety and confusion were reported in greater than 2% of patients.[Ref]

Other

Very common (10% or more): Neck pain related to cervical dystonia (up to 17%), pain (up to 13%)

Common (1% to 10%): Asthenia, accidental injury

Frequency not reported: Chills, malaise, fever, vertigo, otitis media, tinnitus, tremor[Ref]

Chills, malaise, fever, vertigo, otitis media, tinnitus, tremor were reported in greater than 2% of patients.[Ref]

Genitourinary

Urinary tract infection, cystitis, and vaginal moniliasis were reported in greater than 2% of patients.[Ref]

Frequency not reported: Urinary tract infection, cystitis, vaginal moniliasis[Ref]

Oncologic

Neoplasm was reported in greater than 2% of patients.[Ref]

Frequency not reported: Neoplasm[Ref]

Frequently asked questions

References

1. Product Information. Myobloc (rimabotulinumtoxinB). Elan Pharmaceuticals. PROD.

2. Cerner Multum, Inc. UK Summary of Product Characteristics.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.