Botox could help some people with nagging chronic coughs that haven't responded to standard treatment, according to a new report on four patients.
Botox, or botulinum toxin type A, is perhaps best known as a wrinkle-filler, but it has medical uses including treating spastic muscles in patients with cerebral palsy and drying up excessive sweating.
The new findings suggest that Botox might also help quiet coughs, although it is not FDA-approved for this use. And the study's authors caution that the toxin should not be seen as a "panacea."
"Our series involved a small subset of patients who were refractory (not responding) to other therapies despite extensive medical evaluation," Dr. Michael W. Chu of Eastern Virginia Medical School in Norfolk told Reuters Health via e-mail.
Any cough that lasts for more than three weeks, even after treatment, is considered to be chronic, Chu and his colleagues note in their report. Several medical conditions can lead to chronic cough, such as asthma, chronic bronchitis, and reflux, and usually treating the underlying condition improves the cough. Nevertheless, a few patients continue to cough despite treatment.
Chu and his colleagues reviewed patient records for their medical center and found 438 patients who had been treated for spasm of the larynx and chronic cough, six of whom received Botox. They describe the cases of four of these patients in the medical journal, Archives of Otolaryngology — Head and Neck Surgery.
The patients included three women and one man. All had previously received a variety of medications, while three had also undergone voice or speech therapy, to no avail.
Patient 1, a 64-year-old man, had retired from his job as an attorney due to his chronic cough, which he'd had for 30 months. Patient 2, a 38-year-old teacher, had suffered from chronic cough for eight months. Patient 3, a 55-year-old teacher, had been coughing for 30 years. Patient 4 was 41, and sought treatment for her chronic cough of 2 years because of "social embarrassment, causing her to avoid dating and other social activities."
The patients were given several injections into one or both of the pair of muscles running along the vocal cords. All experienced "significant relief of cough," the researchers found.
Two patients showed substantial increases in their voice-related quality of life, although one patient's actually decreased due to the breathiness of her voice. Despite the decline, this patient — the 41-year-old woman who'd stopped dating — reported being happy with the treatment and returning to normal social activities.
The researchers hypothesize that some cases of chronic cough are related to dysfunctional nerve feedback involving the system that typically controls the cough reflex, and that Botox likely worked by interrupting abnormal nerve feedback.
Because the study didn't compare Botox to other therapies, or to a placebo, it is impossible to say whether it is more or less effective than other treatments. Nevertheless, the researchers conclude, it "can be considered for the treatment of chronic cough refractory to other medical therapies."