Currently, the approved dosage of ribavirin has not been studied in patients with ‘normal' alanine aminotransferase levels.
Dr Karin Jorga and colleagues from Switzerland performed modeling, and simulations using generalized additive models to predict the incidence of anemia and rate of sustained virological response in patients with Hepatitis C virus genotype 1.
|The simulations predicted that virological response rates would increase from 39% to 48%|
The patients had persistently ‘normal' alanine aminotransferase levels treated with peginterferon a-2a (40KD) 180 µg/week plus ribavirin 1000/1200 mg/day for 48 weeks.
The model-based simulations predicted that virological response rates would increase from 39% to 48% if these patients were to receive the standard weight-adjusted dose of ribavirin.
The team found that this was similar to the predicted 49% virological response rate for genotype 1 patients with elevated alanine aminotransferase levels.
The incidence of anemia was predicted to increase from 13% to 23% in patients with persistently ‘normal' alanine aminotransferase activity.
In addition, the researchers noted that it was higher than that predicted for patients with elevated alanine aminotransferase levels.
However, the difference appeared to be largely explained by the higher proportion of women in the former group.
Dr Jorga's team concluded, "Simulations based on generalised additive model suggest that regimens for patients with Hepatitis C virus genotype 1 should include the standard weight-adjusted dose of repairing."
"Similar sustained virological response rates are predicted to be achieved, regardless of patients' alanine aminotransferase status at baseline."