Botox Could Treat Chronic Cough

By Margarita Nahapetyan

Botox - the most popular and commonly used drug for reducing the appearance of wrinkles and fine lines - could help some individuals resolve chronic cough, claims a new study, although the US Food and Drug Administration (FDA) has yet to approve the medication for this use.

Botulinum toxin type A has also many other medical uses including treating spastic muscles in patients with cerebral palsy and helping those who suffer from excessive sweating. The drug has been approved by the FDA for the treatment of spasticity in the flexor muscles of the elbow, wrist, and fingers in adults.

The new study's principal author, Dr. Michael W. Chu, M.D., of Eastern Virginia Medical School in Norfolk, wrote in his report that any cough that continues for the period of more than 3 weeks, even after treatment, is considered to be chronic. According to doctors, there are several medical conditions that are associated with chronic cough, such as asthma, chronic bronchitis, and reflux, and in most cases addressing and treating the underlying condition improves the cough. However, some individuals still continue to suffer from chronic cough despite treatment.

Dr. Chu and his fellow colleagues conducted a study involving 438 patients, who had been suffering from chronic cough caused by laryngeal hypertonicity and neuroplastic changes. All the patients had been previously prescribed a variety of medications, while three of them had also undergone voice or speech therapy without any success.

The professionals reviewed outcomes for four of the study participants - 3 women and one man with an average age of 55 years - with laryngeal spasm and chronic cough who were administered with several electromyography-guided injections of Botulinum toxin A along their vocal muscles. Later on the experts reported that in all four patients chronic cough was completely treated after a median of seven Botox shots at a mean dose of 4.0 units per session over a treatment period that lasted for two years.

Researchers said that there were no major complications in any of the patients who received Botox shots. Two patients reported that there were significant increases in their voice-related quality of life, and only one patient - 41-year-old woman - said that hers actually decreased due to the breathiness of her voice. However, in spite of this fact, this woman said that overall she was very happy with the treatment that made is possible for her to return to regular social activities.

Dr. Chu and his team speculate that some cases of chronic cough are linked to dysfunctional nerve feedback involving the system that typically is associated with the cough reflex, and that Botulinum toxin most probably worked by interrupting abnormal nerve feedback.

However, because there was no control group or any placebo comparisons, it is not quite possible to make a statement that the treatment of chronic cough with Botox is more effective than any other treatments. But researchers still believe that it can be a treatment option for chronic coughs, saying that more studies will be needed in order to confirm their new findings.

The findings are detailed in the May issue of the journal Archives of Otolaryngology - Head & Neck Surgery.