Chronic cough guideline highlights research needs

Neuromodulatory therapies and speech pathology-based cough suppression are suggested treatment options for unexplained chronic cough in new guidelines from the CHEST Expert Cough Panel.

The panel noted, however, that evidence supporting the diagnosis and management of unexplained chronic cough is limited. As part of the guideline development, they considered approaches for improving related research.

“Persistent cough of unexplained origin is a significant health issue that occurs in up to five percent to 10 percent of patients seeking medical assistance for a chronic cough and from zero percent to 46 percent of patients referred to specialty cough clinics. Patients with unexplained chronic cough experience significant impairments in quality of life …. There is a need to identify effective treatment approaches,” Hunter (New South Wales, Australia) Medical Research Institute, reported.

The panel defined unexplained chronic cough as a cough that persists longer than eight weeks, and that remains unexplained after evaluations and supervised therapeutic trials are conducted.

The panel also suggested the following therapeutic approaches:

• That adult patients have objective testing for bronchial hyperresponsiveness and eosinophilic bronchitis, or be offered a trial of corticosteroid therapy.

• That adult patients have a trial of multimodality speech pathology therapy.

• That inhaled corticosteroids should not be prescribed in adult patients who test negative for bronchial hyperresponsiveness and eosinophilia.

• That a therapeutic trial of gabapentin be offered as long as the risk-benefit profile is discussed with the patients, and as long as reassessment of the risk-benefit profile be conducted at six months – before continuing the drug.

The recommended starting dose is 300 mg daily in those without contraindications, with dose escalation daily as tolerated up to a maximum tolerable dose of 1,800 mg daily in two divided doses.

• That adult patients with a negative work-up for acid gastroesophageal reflux disease not be prescribed a proton pump inhibitor.

The panel’s suggestions are the result of a systematic review of 11 randomized controlled trials and five more efficacious than usual care with respect to cough severity, cough frequency, and cough-related quality of life.

Studies reviewed included data on 570 subjects over age 12 years with chronic cough who received a variety of interventions.

Positive effects on cough-related quality of life were noted for both gabapentin and morphine, but the panel determined that only gabapentin was supported as a treatment recommendation.

Inhaled corticosteroids were not found to be effective for unexplained chronic cough, and esomeprazole was not effective in patients without features of gastroesophageal acid reflux.