What Is Botulinum Toxin in Pain Management?

Botulinum toxin, sold as a drug under the name "Botox" and others, can block nerves and paralyze muscles. This can be useful for management of some types of chronic pain.

Botulinum toxin is a drug produced by Clostridium botulinum, a gram-positive anaerobic bacterium. This same toxin can also cause botulism in the digestive tract from ingestion of contaminated food or an infected wound. 

Botox, the name for the drug made from botulinum toxin, weakens or paralyzes certain muscles or blocks certain nerves. Depending on its use and the condition being treated, the effects can last for up to a year.

In small doses, botulinum toxin is used for a variety of medical conditions, including pain management. 

The pain relief achieved with use of botulinum toxin is believed to result from the secondary effects of muscle paralysis, improved blood flow, the release of nerve fibers under compression by abnormally contracting muscle, and the effects of the toxin on nociceptive neurons (pain receptors).

Botulinum toxin is used to treat painful conditions such as:

• Neuromuscular disorders
  • Tennis elbow
  • Chronic anal fissure
  • Pain attributed to mastectomy and hemorrhoidectomy
  • Headaches (including migraine, tension, and cervicogenic)
  • Piriformis syndrome
  • Facial pain
  • Myofascial pain
  • Temporomandibular joint syndrome (TMJ)
  • Low back pain
  • Chronic prostatic pain
  • Whiplash
• Myofascial pain syndrome
• Painful muscle areas

When patients do not respond to traditional pain management such as pain relievers (analgesics), physical therapy or exercise, and rest, botulinum toxin may be considered.

The following are examples of botulinum toxin products along with their approved medical uses:

• OnabotulinumtoxinA (Botox, Botox Cosmetic)
  • Botox is used to treat
    • Cervical dystonia
    • Severe primary axillary hyperhidrosis
    • Crossed eyes (strabismus)
    • Eyelid twitching (blepharospasm)
  • Botox Cosmetic is used to treat 
    • Moderate to severe glabellar lines (forehead furrows)
• AbobotulinumtoxinA (Dysport) is used to treat 
  • Cervical dystonia
  • Moderate-to-severe glabellar lines in adults
• IncobotulinumtoxinA (Xeomin) is used to treat
  • Cervical dystonia
  • Blepharospasm
• RimabotulinumtoxinB (Myobloc) is used to treat
  • Cervical dystonia

The most common side effects of botulinum toxin include:

• Injection site reactions (such as pain, swelling, or bruising)
• Facial and other muscle weakness
• Flu-like symptoms
• Headache
• Upset stomach
• Temporary drooping eyelids (when injected into the face)
• Respiratory problems
• Problems swallowing 
• Seizures