title: Assessment of the efficacy of reducing peginterferon alpha-2a and ribavirin dose on virologic response in Koreans with chronic hepatitis C.
abstract: OBJECTIVE
  The virologic response of Koreans to combination therapy for chronic hepatitis C is similar to westerns; however, dose modification occurs more frequently in Koreans. We evaluated the rates of peginterferon alpha-2a and ribavirin dose modifications and their effect on the virologic response in Koreans.
  
  
  METHODS
  Patients with detectable HCV RNA and enrolled from multicenters were treated with peginterferon alpha-2a (180 microg/week) and ribavirin (800 mg/day) for 24 weeks (genotype non-1, n=37) or peginterferon alpha-2a (180 microg/week) and ribavirin (1,000-1,200 mg/day) for 48 weeks (genotype 1, n=55).
  
  
  RESULTS
  Early virologic response (EVR) and sustained virologic response (SVR) were 77.2% (genotype 1, 75%; non-1, 81%) and 66.3% (genotype 1, 56%; non-1, 81%), respectively. The frequency of dose modification was 32.6% within the first 12 weeks and 52.2% during the entire treatment period. No difference was found in SVR regardless of dose modification. However, the SVR for patients using >or=80% of the peginterferon dose was significantly higher than for those using <80% (81.3 vs. 50.0%, p=0.007), despite varying ribavirin doses. No difference was found in SVR regardless of whether the ribavirin dose was <80% or not. These results did not change based on genotype.
  
  
  CONCLUSIONS
  We suggest that using at least 80% of the peginterferon alpha-2a dose in Koreans not only maintains SVR but also reduces drug side effects during the entire treatment period. A lower dose of ribavirin may be as efficacious as a standard dose.
authors.affiliation: Department of Internal Medicine, WHO Collaborating Center on Viral Hepatitis, The Catholic University of Korea College of Medicine, and Seoul St. Mary's Hospital, Seoul, Korea.
authors.forename: Jung Hyun
authors.initials: JH
authors.lastname: Kwon
authors.forename: Si Hyun
authors.initials: SH
authors.lastname: Bae
authors.forename: Jong Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Seung Kew
authors.initials: SK
authors.lastname: Yoon
authors.forename: Kwan Soo
authors.initials: KS
authors.lastname: Byun
authors.forename: Seung Woon
authors.initials: SW
authors.lastname: Paik
authors.forename: Young Suk
authors.initials: YS
authors.lastname: Lim
authors.forename: Han Chu
authors.initials: HC
authors.lastname: Lee
authors.forename: Kwang Hyub
authors.initials: KH
authors.lastname: Han
authors.forename: Kwan Sik
authors.initials: KS
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000008:administration & dosage*; D004359:Drug Therapy, Combination; D005260:Female; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D011092:Polyethylene Glycols / Q000008:administration & dosage* / Q000009:adverse effects; D012367:RNA, Viral / Q000097:blood; D011994:Recombinant Proteins; D012254:Ribavirin / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D012367:RNA, Viral; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012254:Ribavirin; C100416:peginterferon alfa-2a