There needs to be a better understanding of cough drivers in patients as treatments have stopped working, said Krishna M. Sundar, MD, clinical professor, Pulmonary Division, Department of Medicine, and medical director, Sleep-Wake Center, University of Utah.
There needs to be a better understanding of cough drivers in patients, mainly because treatments have stopped working and because they are increasingly sensitized to minor stimuli that trigger their cough reflex, said Krishna M. Sundar, MD, clinical professor, Pulmonary Division, Department of Medicine, and medical director, Sleep-Wake Center, University of Utah.
What criteria must be met to diagnose chronic cough?
It’s a clinical assessment; it’s all based on clinical history. And if they've been coughing for more than months, that qualifies them as having chronic cough. It’s purely based on duration.
What lessons can be learned from treatment failure?
So that's a great question, because a lot of our treatments have not worked for years. Because, again, we need to understand what is driving the cough in these patients. And it's only in the last decade that there is a concept of something called “cough hypersensitivity” that has evolved, which means that the threshold for coughing for these patients is much lower than the rest of the population.
These patients start coughing when they start talking, when they go out into cold air, or when they lay down. Minor stimuli which would normally not lead to coughing in you or me can trigger coughing in these patients, so they are very much sensitized in terms of their cough reflex. And we don't know why this is so. So therefore most of the new therapies that are being done are targeting the cough reflex per se. They are directed at molecules that drive the cough impulse. And it may be at the peripheral level, most of them are coughing at the peripheral level or the central ganglia level. And there is a whole pipeline of drugs that's coming out that's looking to target the cough hypersensitivity.