Botox demonstrates efficacy in wide array of medical uses

Botox (onabotulinumtoxinA, Allergan) has made a name and a home for itself in the offices of cosmetic surgeons around the world as a wrinkle smoothing agent, but the drug's reach and utility extend far beyond the confines of the aesthetic arena as well.

Originally used by ophthalmologists to treat strabismus, the versatile neurotoxin's most recent indication approved by the Food and Drug Administration (FDA) is for treatment of migraine headaches.

Botulinum toxin blocks the release of acetylcholine, which is required for muscle contraction, at the neuromuscular junction. This weakens muscular contraction and inhibits glandular secretions.^1,2,3 The effect typically lasts from three to six months, and the mechanism of action enables its use for a wide variety of on- and off-label treatments, including focal and cervical dystonia, blepharospasm, strabismus, stuttering, migraine headaches, spastic bladder, hyperhidrosis and sialorrhea, among other things.

Daniel Kantor, M.D., president of the Florida Society of Neurology and medical director of Neurologique, Ponte Vedra, Fla., an organization dedicated to patient care, research and education, says that "one of the ways Botox is used is to weaken overactive muscles. For example, people with cervical dystonia have a twisting of their neck where one shoulder may be higher than the other, and this can lead to pain and disfigurement. Botox can help here by weakening muscles that are firing when they should be at rest."

In cases such as these, the patient sees a neurologist every three to four months for muscle injections that are usually performed under electromyography (EMG) guidance, Dr. Kantor says.

EASING THE HEADACHE Most recently, the FDA approved Botox for the prevention of chronic migraine. Approximately 3.2 million Americans (mostly women) suffer from chronic migraines, which are headaches that occur 15 or more days per month.

"This condition leads to loss of time from work, emergency room visits and prescription drug use," says Dr. Kantor, who is board-certified in headache medicine. "One-hundred-fifty-five units of Botox can be injected in a particular pattern around the head and neck to prevent these headaches."

Jay Bhatt, M.D., who specializes in using Botox to treat migraines, says, "I have patients who swear by this treatment. This therapy has really changed people's lives." Dr. Bhatt is an Indiana University Health-affiliated neurologist with Indiana University Health Physicians Neurology; and an assistant professor of clinical neurology for the Indiana University School of Medicine, Indianapolis. He has a special clinical interest in Botox and administers the treatment more than any other physician in Indiana, he says.

Dr. Bhatt says the reason botulinum toxins are used so widely is because of their mechanism of action, which is to selectively paralyze or weaken muscles.

"Many conditions are manifested by an area of the body having increased muscle tone, so if we can decrease that tone, in a lot cases that can relieve pain, relieve discomfort and increase the person's function," he says.

THE COSMETIC CONNECTION The recognition that Botox relieves migraine headache pain originated with patients who were getting Botox injections for the treatment of forehead wrinkles. Dr. Bhatt says these patients, who also suffered from migraine headaches, reported to the physician who was treating their forehead wrinkles that their migraine headache pain stopped or dissipated after getting the injections for cosmetic purposes.

These anecdotal reports made their way to neurologists, who then began to research the connection between Botox and migraine pain reduction, and earlier this year the FDA approved the indication. Migraine treatment includes frontalis, corrugator and posterior injections, among others.

"A lot of these are in the same places that someone would be injected for cosmetic purposes, though noticeably absent are the injections at the outside of the eyes — the crow's feet," Dr. Bhatt says.

The primary benefit of Botox for headache treatment is the absence of side effects that are typical of systemic migraine medications. "A lot of oral medications that we prescribe for the conditions that can be treated with Botox have a memory-clouding effect or can make people feel like they are in a fog," Dr. Bhatt says. "While that may work to settle down the person's headache, they can't function very well walking around in a fog."