Pharmacotherapeutic Options for Chronic Refractory Cough.

Currently-available antitussive drugs (i.e., opioids and gabapentin) are centrally-acting drugs primarily used for pain and neuropathic conditions; they were not designed for cough and have limitations with respect to efficacy and safety. Due to the success of gefapixant, a first-in-class P2X3 antagonist, early phase trials with different therapeutic targets in the cough reflex pathways have been conducted; these are expected to control cough hypersensitivity, while preserving protective cough reflex. However, the reported effects of antitussive drugs depend on the clinical context, cough outcome measures or cough characteristics. Further biomarkers are needed to accurately predict responders to different antitussive drugs.