Comorbidities and Prescribed Medications in Korean Patients with Chronic Hepatitis C: A Nationwide, Population-Based Study

Extrahepatic comorbidities and comedication are important to consider in the treatment of chronic hepatitis C (CHC) patients with direct-acting antivirals (DAAs) due to the risk of drug-drug interaction (DDI) and the effect of comorbidities on clinical outcomes. This study aimed to investigate the detailed profiles of comorbidities and comedication among Korean CHC patients. All adult patients (≥18 years old) with a primary diagnostic code of CHC in 2013 were selected from the National Health Insurance claims database. For each patient, all ICD-10 codes listed as primary or secondary diagnoses and all prescribed medications were collected. Among 47,104 CHC patients (median age, 57 years; male, 49.3%), 84.8% had at least one comorbidity for a mean number of 2.4, which increased with age. The most prevalent comorbidities were hypertension, esophagitis, dyslipidemia, diabetes mellitus, and peptic ulcer. Overall, 96.8% of the patients took at least one prescribed medication, with a mean of 8.1 medications/ year, and the three most common drug types were analgesics, gastrointestinal agents, and antibacterials. Use of at least one drug with a DDI risk category of "contraindicated medication" or "required dose-reduction/additional monitoring" was observed in 97% of the overall patients. The proportion of prescribed medications that were contraindicated with DAAs varied from 2.0% to 38.9% depending on the hepatitis C virus regimen. The majority of CHC patients had comorbidities; almost all patients took multiple prescribed medications, the number of which increased with age, and significant DDI risk was present in 97% of this Korean patient cohort. Comorbidities and comedication profiles should be considered during DAA therapy.