From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Treatment for Frey's syndrome 2 years post-operation should focus on managing the characteristic facial sweating and flushing that occurs during eating, with botulinum toxin A (Botox) injections being a highly effective treatment option, as evidenced by studies such as 1 and 2. The first-line treatment is often topical antiperspirants containing aluminum chloride hexahydrate, but for patients who don't respond adequately to antiperspirants, botulinum toxin A injections are a viable alternative.
- The average treated area per patient is around 26 cm2, with an average of 38 units of Botulinum Toxin per patient injected, as seen in 1.
- The time lapse until improvement is typically around 5.5 days, with the effects of the treatment being long-lasting and side effects being minimal and temporary, as reported in 1.
- A second injection may be needed after 15 to 18 months of the first, although the affected area is usually smaller, as noted in 1.
- Anticholinergic medications like glycopyrrolate can also help but may cause side effects like dry mouth and blurred vision.
- For severe cases unresponsive to these approaches, surgical options include interpositional barriers or neurectomy procedures, which target the aberrant nerve regeneration that occurs when parasympathetic fibers meant for the parotid gland mistakenly connect to sweat glands and blood vessels in the skin, as discussed in 3 and 4. However, the most recent and highest quality study 1 suggests that botulinum toxin A injections are a highly effective and safe treatment for Frey's syndrome, making it the preferred treatment option.