Can Botulinum Toxin Be Used for Pain Relief?

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.

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

Cervical dystonia (abnormal neck muscle contraction)
Blepharospasm (involuntary eye twitching)
Strabismus (crossed eyes)
Limb spasticity (limb muscle stiffness)
Neurogenic bladder (loss of bladder control)
Migraine headache
Axillary hyperhidrosis (excessive armpit sweating)
Sialorrhea (drooling caused by cerebral palsy)

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.

QUESTION

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

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:

Chronic migraine headache
Cervicogenic headache
Tension headache
Medication overuse headache
Whiplash associated neck pain
Temporomandibular joint disorder
Nerve pain such as
- Trigeminal neuralgia
- Postherpetic neuralgia
- Neuropathic pain (pain from nerve damage)
Chronic lower back pain
Piriformis muscle syndrome
Chronic prostatic pain
Chronic anal fissure
Myofascial pain syndrome
Postoperative pain and spasm in cerebral palsy
Postoperative pain from mastectomy
Postoperative pain from hemorrhoidectomy
Tennis elbow (lateral epicondylitis)
Knee pain
Shoulder pain

Latest Chronic Pain News

Trending on MedicineNet

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.

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
  - Cervical dystonia
  - Axillary hyperhidrosis
  - Strabismus
  - Blepharospasm
  - Neurogenic detrusor hyperactivity
  - Chronic migraine
  - Upper limb spasticity
- 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:

Injection site reactions such as
- Pain
- Redness
- Bruising
- Infection
- Hematoma
Flu-like symptoms such as
- Fever
- Chills
- Lightheadedness
- Headache
Muscle soreness
Hypertension
Nausea
Diarrhea
Abdominal pain
Swallowing difficulties (dysphagia)
Respiratory problems
Pain or weakness in neighboring muscles
Neck weakness
Fatigue and lethargy
Dizziness
Dry mouth
Hoarse voice (dysphonia)