What is botulinum toxin?

Botox and its analogs, widely administered for cosmetic purposes, can also reduce chronic pain by deadening nerves and/or releasing the pressure on the nerves from adjacent spasming muscles.
Botox and its analogs, widely administered for cosmetic purposes, can also reduce chronic pain by deadening nerves and/or releasing the pressure on the nerves from adjacent spasming muscles.

Botulinum toxin is one of the most toxic biological substances found on earth, produced by anaerobic bacteria known as Clostridium botulinum. Botulinum toxin is a neurotoxin excreted by C. botulinum when the bacterial spores find the right environment to germinate and multiply, for instance, in the human gut where it may cause botulism, a serious type of food poisoning.

Botulinum toxin binds to nerve terminals in muscles and prevents the release of acetylcholine. Acetylcholine is the principal neurotransmitter in neuromuscular junctions, which activate muscles. The blockage of acetylcholine stops the transmission of nerve signals and paralyzes the muscles.

There are seven identified types of botulinum toxin, named A to G, with two sub-types in C. Currently, botulinum toxin type A is being studied for use in pain management. Some investigators suggest an eighth type but others claim it is a combination of parts of types A and F.

What is botulinum toxin used for?

Botulinum toxin is referred to as a miracle poison because its pharmacologic properties can be put to therapeutic use with minute and carefully administered doses. Botulinum toxin is purified and diluted with human serum albumin before use on people.

Botulinum toxins are commonly administered to smooth out facial wrinkles from aging, such as frown lines (glabellar lines) and crow’s feet (canthal lines). Botulinum toxin injections provide temporary relief by relaxing stiff or hyperactive muscles in certain conditions such as

Can botulinum toxin be used for pain relief?

The mainstay of pain management therapy for chronic pain conditions is rest, physical therapy and painkillers. Researchers are increasingly investigating the use of botulinum toxin for pain relief (analgesia), with fewer side effects than conventional painkillers.

The exact mechanism of botulinum toxin’s analgesic effects is not fully understood. Some amount of indirect pain relief may be from the relaxation of taut muscles which can improve blood supply and release compressed nerves.

Ongoing studies show that botulinum toxin also blocks certain pain transmitting neurotransmitters such as glutamate and substance P, reducing the intensity and duration of pain. Further studies are required to establish the direct and/or indirect analgesic effects of botulinum toxin.

SLIDESHOW

Pain Management: Surprising Causes of Pain See Slideshow

When is botulinum toxin used for pain relief?

Several studies have found botulinum toxin to be effective for temporary pain relief from painful neuromuscular conditions. People treated with botulinum toxin for muscle contraction have also reported pain reduction in those muscles. Botulinum toxin A has FDA approval for use in migraine headaches and pain from cervical dystonia.

Botulinum toxin for myofascial pain syndrome (muscle pain) is considered only when a patient does not respond to traditional forms of treatment. Some studies have reported that botulinum toxin has been effective in myofascial pain caused by trigger points.

Clinical trials have indicated that use of botulinum toxin A for pain management is effective in conditions that include:

How is botulinum toxin injection administered?

Botulinum toxin therapy is individualized depending on the patient’s needs. Depending on the condition treated, botulinum toxin injection may be administered

  • Into the inner layer of the skin (intradermal)
  • Into the tissue under the skin (subcutaneous)
  • Into the affected muscle (intramuscular)
  • Into the bladder for neurogenic bladder
  • Into the salivary glands for sialorrhea

For certain muscular injections, the doctor may use electromyography or electrical muscle stimulation for needle guidance. The doctor may also give a muscle relaxant to prevent short-term pain or discomfort from the injection.

Botulinum toxin’s effects on the targeted nerve terminals are irreversible, but new nerve terminals normally sprout within about three months, returning sensation and function to the muscle. . Botulinum toxin injections are usually repeated every three to four months, but the period between injections may increase, because the muscle atrophies to some extent with each injection.

QUESTION

Medically speaking, the term "myalgia" refers to what type of pain? See Answer

What are the FDA-approved botulinum toxin drugs for pain relief?

The use of botulinum toxin A for pain relief has FDA approval only for:

  • Pain related to cervical dystonia
  • Chronic migraines

The FDA-approved botulinum toxin drugs are:

  • OnabotulinumtoxinA (Botox, Botox Cosmetic)
    • Botox is approved for
    • Botox Cosmetic is approved for
      • Glabellar lines
      • Canthal lines
  • AbobotulinumA (Dysport)
    • Approved for
      • Upper and lower limb spasticity
      • Cervical dystonia
      • Glabellar lines
      • Lower limb spasticity in children aged 2 years or older
  • IncobotulinumtoxinA (Xeomin)
    • Approved for
      • Upper and lower limb spasticity
      • Cervical dystonia
      • Blepharospasm
      • Glabellar lines
      • Chronic sialorrhea
  • PrabotulinumtoxinA (Jeuveau)
    • Approved for moderate to severe glabellar lines.
  • RimabotulinumtoxinB (Myobloc)
    • Approved for cervical dystonia

What are the side effects of using botulinum toxin for pain relief?

Side effects of botulinum toxin are few and usually resolve on their own. Potential side effects when used for pain relief include:

Subscribe to MedicineNet's General Health Newsletter

By clicking Submit, I agree to the MedicineNet's Terms & Conditions & Privacy Policy and understand that I may opt out of MedicineNet's subscriptions at any time.

Summary

Botulinum toxin from bacteria Clostridium botulinum causes a deadly form of food poisoning called botulism. Harnessed as a drug, however, it can improve wrinkles, deaden pain and relax spasming muscles. Botox is the most common formulation, but there are other variants and brands meant for different conditions.

Treatment & Diagnosis

Medications & Supplements

Health Solutions From Our Sponsors

FDA Logo

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Medically Reviewed on 7/20/2020
References
Medscape Medical Reference
CONTINUE SCROLLING FOR RELATED SLIDESHOW