What are BOTOX® and MYOBLOC®?
BOTOX® and MYOBLOC® are neurotoxins (muscle-relaxing drugs) that are derived from the toxin of the same bacterium that causes food poisoning (Clostridium botulinum).
In large doses such a neurotoxin is fatal, but in small doses it provides a therapeutic effect. It has been used to successfully treat uncontrolled muscle contractions of the eyelid, cervical and limb dystonia (a neurological movement disorder), and is also being investigated for myofascial pain.
Because it is a neurotoxin, it is important to understand how the drug works, how effective it is, and any possible side effects you might develop.
Is a neurotoxin really safe?
Neurotoxins are produced in a controlled laboratory setting under sterile conditions. There are seven different serotypes (A, B, C, D, E, F, and G), and each of these serotypes has different properties affecting the muscles differently.
The most common type used is Type A, known as BOTOX®, which has been approved by the FDA since 1989.
The other commonly used serotype is Type B, which is known as MYOBLOC® in this country and has been approved by the FDA since 2001. In large doses (as with food poisoning) it is fatal, but in small doses, over very specific, localized areas, it has a therapeutic effect that works on nerves leading to muscles.
The doses that are used are only injected into selected muscle fibers in quantities well below a toxic level. The toxin does not enter the blood stream.
How do neurotoxin injections work?
By means of a substance called acetylcholine, the brain sends electrical signals to your muscles, causing them to contract and move. An injection of BOTOX® or MYOBLOC® blocks the release of acetylcholine, thus preventing the muscle from receiving the message to contract, and painful or irritating muscle spasms stop or are greatly reduced.
Although BOTOX®/MYOBLOC® injections are not a cure, they can bring dramatic results. Symptoms usually begin to decrease within a few days, and the effects of the injection can last up to six months.
The injections may also be done in conjunction with an EMG to help your physician more accurately target the desired muscle fibers to get the best response to the treatment.
Is the treatment painful?
We use a very fine needle and give one to three injections per muscle. Some of our patients report minor, temporary discomfort from the injections.
How do I know if I am a good candidate?
Your APM physician can best answer this question. He or she will take a complete medical history so that other medications will not interfere with the effects of BOTOX®/MYOBLOC®. However, BOTOX®/MYOBLOC® should not be used if you are pregnant, nursing, or taking certain medications.
How fast does BOTOX®/MYOBLOC® start to work?
Although response rates vary, pain usually begins to decrease within a few days, with the maximum effect expected about two weeks after the injections.
How long will the effects last?
The neurotoxin is effective until the neurons start to regrow (after about 3 to 4 months), reactivating the muscle fibers. Because of this activity, the treatment is usually repeated no more often than every three months. Physical therapy may be recommended after the injections to stretch and restore normal muscle function during the period of decreased muscle activity.
Can I receive BOTOX®/MYOBLOC® treatments indefinitely?
Acceptable safety in long-term treatment has been established by the medical community. However, in rare cases, the human body may form antibodies to the proteins in BOTOX®/MYOBLOC®, which would render the therapy ineffective. To lessen the chance of this happening, we limit treatment frequency to every three months.
What about risks and side effects?
All medications have side effects. With BOTOX®/MYOBLOC®, these are usually mild and short-lived. You may notice temporary weakness of the muscles that were injected, or some tenderness at the injection site. Less-common side effects are low-grade fever or flu-like symptoms within the first 24 hours.