Nov. 21, 2002 -- There was a time -- say, last decade - when botulinum toxin was best known as a poison so deadly that a single gram could reportedly kill millions of people. Now a household name, Botox is the most widely used treatment for so-called "frown lines." But one expert raises the issue of whether we really know the potential long-term effects of this wrinkle-smoothing drug.
"In this atmosphere of 'Botox parties,' it is easy to forget that botulinum toxin is a potent [nerve toxin] and that its very long-term effects are still unknown," neurophysiologist V. Peter Misra, MD, writes in the Nov. 23 issue of the British Medical Journal.
Misra says his editorial is not suggesting that Botox is unsafe or has "unknown" side effects.
"To the best of my knowledge, the safety record of Botox has been well established," he tells WebMD. "[The purpose of the editorial] was to point out that the indications for Botox use are expanding, and relevant clinical studies need to be performed to establish efficacy and best standard treatment for these conditions."
When injected in small doses into specific muscles, the toxin smoothes wrinkles by paralyzing those muscles. Though the FDA has approved Botox only for wrinkles between the eyebrows, the toxin is commonly used cosmetically in other areas, such as the forehead and around the eyes.
Botox is still a key ingredient in biochemical warfare, and there are reports that Iraq "favors" this toxin over anthrax and other poisons. But research suggests the same effect that makes it so effective in weapons of mass destruction provides for some darn versatile medicine. Recent studies indicate that Botox's muscle-freezing action appears effective in treating a host of conditions - including bladder dysfunction, excessive sweating, cerebral palsy, post-stroke spasticity, back pain, and even anal fissures.
Some of the most promising research, however, has been in using this "wrinkle remedy" as a treatment for migraines and headaches. In June, findings of 13 studies presented at the American Headache Society annual meeting suggested that Botox was effective in reducing migraines and other severe headaches. The reason isn't clear, but some researchers believe Botox blocks nerves that relay pain messages to the brain and relaxes muscles, making them less sensitive to pain.
"The biggest advantage to Botox is its lack of side effects, especially compared to other medications," neurologist William Ondo, MD, of Baylor College of Medicine, said in June in an AHS news release.
"The FDA's first consideration is always safety, and I feel this product is very safe, or, obviously, I wouldn't have recommended its approval," says dermatologist Ella L. Toombs, MD, a former FDA official who served on the committee that approved Botox as a wrinkle treatment.
What isn't widely known, Toombs says, is that drugs such as Botox -- considered a lifestyle enhancer more than a lifesaver -- actually fall under more FDA scrutiny than proposed treatments for serious conditions.
"Every product the FDA evaluates looks at its benefit-to-risk ratio," she tells WebMD. "If you look at it from the standpoint of a cancer patient, one might be more willing to accept the adverse events of a certain drug more readily than when using a product that you don't necessarily need to improve health. Therefore, we really look at their safety."
Prior to its approval as a wrinkle treatment, the FDA initially approved Botox in 1989 to treat two eye disorders -- uncontrollable eyelid spasms and misaligned eyes -- and in 2000 to treat a condition that causes severe neck and shoulder contractions. It was a Canadian eye surgeon who first noted its wrinkle-reducing properties.
In other countries, such as the U.K., Botox has already been approved for other conditions, including excessive sweating and spasticity.
"Interestingly, except for cosmetic use, the U.S. is usually far behind other countries in the drug approval process," says Allergan spokeswoman Christine Cassiano, who acknowledges that Botox is currently being studied by private researchers and in corporate-funded clinical trials to test some of its other potential uses.