Prescription patterns and symptom relief of antitussives and expectorants in patients with cough: a nationwide study in Korea

Background: Limited data are available on the prescription patterns and efficacy of antitussives and expectorants for patients with acute and chronic cough. This study examined the use and efficacy of these medications in a nationally representative sample of Korean patients. Methods: We examined 4,206,016 individuals from the National Health Insurance Service (NHIS)-National Health Information Database (NHID) between 2015 and 2017. Among them, a sample of 10% (n=420,602) was retrieved for the diagnosis of respiratory diseases using the International Classification of Diseases, 10^th edition (ICD-10; J00–J99), or the prescription of antitussives and expectorants for cough (ICD-10; R05). The acute cough group included those who were prescribed medications within 4 weeks of initial diagnosis (prescription within 14 days), whereas the chronic cough group included patients who were prescribed medications within 16 weeks of initial diagnosis (prescription within 56 days). If the prescription was discontinued or not changed to an alternative drug after the initial prescription, these cases were considered to have achieved symptom relief. Results: This study included 288,460 patients (971,065 cases) with acute cough and 5,888 patients (15,399 cases) with chronic cough. ‘Expectorants, excluding combinations with cough suppressants’ had the highest prescription rates in both groups (acute cough, 63.8%; chronic cough, 61.7%), and showed the highest symptom relief regardless of the number of medications prescribed (acute cough, 84.3%; chronic cough, 70.4%). Conclusions: ‘Expectorants, excluding combinations with cough suppressants’ were the most prescribed and effective medications for relieving cough symptoms in Korea patients. Further studies are needed to determine the optimal duration for using antitussives and expectorants in cough management.