Postmarketing reports indicate that the effects of BOTOX and all botulinum toxin products may spread from the area of injection to produce symptoms consistent with botulinum toxin effects. These may include asthenia, general ized muscle weakness, diplopia, ptosis, dysphagia, dysphonia, dysarthria, urinary incontinence and breathing difficulties. These symptoms have been reported hours to weeks after injection. Swallowing and breathing difficulties can be life threatening and there have been reports of death. The risk of symptoms is probably greatest in children treated for spasticity but symptoms can also occur in adults treated for spasticity and other conditions, particularly in those patients who have an underlying condition that would predispose them to these symptoms. In unapproved uses, including spasticity in children, and in approved indications, cases of spread of effect have been reported at doses comparable to those used to treat cervical dystonia and spasticity and at lower doses. [See WARNINGS AND PRECAUTIONS]

BOTOX® increases the incidence of urinary tract infection. Clinical trials for overactive bladder excluded patients with more than 2 UTIs in the past 6 months and those taking antibiotics chronically due to recurrent UTIs. Use of BOTOX® for the treatment of overactive bladder in such patients and in patients with multiple recurrent UTIs during treatment should only be considered when the benefit is likely to outweigh the potential risk.
[b] These values represent the prospectively planned method for missing data imputation a nd statistical test. Sensitivity analyses indicated that the 95% confidence interval excluded the value of no difference between groups and the p -value was less than 0.05. These analyses included several alternative missing data imputation methods and non-parametric statistical tests.
Individuals with peripheral motor neuropathic diseases, amyotrophic lateral sclerosis or neuromuscular junction disorders (e. g., myasthenia gravis or Lambert-Eaton syndrome) should be monitored when given botulinum toxin. Patients with neuromuscular disorders may be at increased risk of clinically significant effects including generalized muscle weakness, diplopia, ptosis, dysphonia, dysarthria, severe dysphagia and respiratory compromise from therapeutic doses of BOTOX [see Dysphagia And Breathing Difficulties].

Botox comes as a crystalline substance from the manufacturer, which then has to be reconstituted with saline or another liquid. Practitioners add varying amounts of liquid when reconstituting it. Although there is no right or wrong amount of liquid to add, most physicians add about 2 mL-3 mL (about a half a teaspoon) of liquid to each vial. Some add quite a bit more, which can lead patients to think they are getting more Botox when, in reality, they are getting the same or less amount of Botox than samples reconstituted in a stronger way. It is the total dose of medication, not the volume of liquid, that leads to the desired effect.

Botox was introduced to the world in the late 1980s by ophthalmologists, who began using it to treat optic muscle disorders. It was approved by the Food and Drug Administration (FDA) for the treatment of moderate to severe frown lines between the eyebrows (glabellar lines) in 2002, and its popularity has soared ever since. Botox is consistently one of the top five nonsurgical cosmetic procedures performed each year.
In the mid-1990s, people who received BOTOX for other conditions reported improvement in their chronic migraine pain. A two-phase study was conducted, treating patients who averaged 20 headache days a month. They received BOTOX injections every twelve weeks for 56 weeks. At the end of that period, 70% of the patients had fewer than half the number of headaches they had before treatment. The FDA officially approved BOTOX to treat chronic migraine in October of 2010. Since then, more than 100,000 patients have been treated.
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.