Botox, or onabotulinumtoxinA, is used for three main purposes: muscle spasm control, severe underarm sweating and cosmetic improvement. In this article we concentrate on the third use, achieved with the product called Botox Cosmetic, which contains botulinum toxin type A (the active ingredient), human albumin (a protein found in human blood plasma) and sodium chloride.
BOTOX blocks neuromuscular transmission by binding to acceptor sites on motor or sympathetic nerve terminals, entering the nerve terminals, and inhibiting the release of acetylcholine. This inhibition occurs as the neurotoxin cleaves SNAP -25, a protein integral to the successful docking and release of acetylcholine from vesicles situated within nerve endings. When injected intramuscularly at therapeutic doses, BOTOX produces partial chemical denervation of the muscle resulting in a localized reduction in muscle act ivity. In addition, the muscle may atrophy, axonal sprouting may occur, and extrajunctional acetylcholine receptors may develop. There is evidence that reinnervation of the muscle may occur, thus slowly reversing muscle denervation produced by BOTOX.
Micropigmentation, or permanent makeup, is a procedure in which iron oxide pigment is injected into the dermis. This procedure can improve the appearance of thin eyebrows and lips and may be beneficial for those with makeup allergies. Swelling is common after the procedure. The patient may be instructed to apply ice and/or ointment to the treated area.
Patients with diabetes mellitus treated with BOTOX® were more likely to develop urinary retention than nondiabetics. In clinical trials, 12.3% of patients (10/81) with diabetes developed urinary retention following treatment with BOTOX® 100 Units vs 0% of patients (0/69) treated with placebo. In patients without diabetes, 6.3% of patients (33/526) developed urinary retention following treatment with BOTOX® 100 Units vs 0.6% of patients (3/516) treated with placebo.
Calcitonin gene-related peptide (CGRP) is a neuropeptide found all over the body, says Dr. Amaal Starling, an Assistant Professor of Neurology at the Mayo Clinic in Phoenix. This neuropeptide attaches to a receptor called a CGRP receptor. CGRP and its receptor are involved in numerous bodily processes—from gastrointestinal movement to the transmission of pain. Over the past few decades, there has been increasing evidence that CGRP plays a role in both migraine and cluster headache. During a migraine attack, researchers have found increased levels of CGRP in patients’ blood and saliva. They discovered migraine medications like sumatriptan reduced levels of CGRP in patients living with migraine. They also found that patients with chronic migraine—meaning 15 or more migraine days per month, eight of which either meet criteria for migraine or are treated with migraine-specific medication—had chronically elevated levels of CGRP. In addition, recent research found that giving a patient with migraine an infusion of CGRP would lead to a migraine-like attack. “All of these studies led to the hypothesis that CGRP and its receptor play a key role in migraine, as well as in cluster headache,” Dr. Starling says.
Just because not every cosmetic Botox procedure is FDA-approved doesn't mean it's not safe and effective, if done properly. Off-label procedures are still within the standard of care, and there are tons of them. “There are so many non-FDA-approved applications for Botox,” says dermatologist Dendy Engelman, MD. “It can be used to decrease scalp-sweating (which helps prolong blowouts), correct a droopy nasal tip (called nasal-tip ptosis), fix brow asymmetry, minimize bunny lines from wrinkling your nose, decrease skin oiliness, minimize the appearance of pores...” The list goes on and on.
It is not known whether BOTOX® is safe or effective to treat increased stiffness in upper limb muscles other than those in the elbow, wrist, fingers, and thumb, or in lower limb muscles other than those in the ankle and toes. BOTOX® has not been shown to help people perform task-specific functions with upper limbs or increase movement in joints that are permanently fixed in position by stiff muscles. BOTOX® is not meant to replace existing physical therapy or other rehabilitation that may have been prescribed.