Figure 4: Proposed algorithm for the use of protease inhibitors in HCV genotype 1 infected patients who have had previous virological failure on treatment. Pretreatment assessment should include careful consideration of lifestyle factors, comorbid conditions, potential drug interactions, assessment for the presence of cirrhosis, and the presence of factors predictive of a poor response to therapy. Identification of the degree of previous response should be attempted. If this information is not available, patients should be considered as prior null responders to maximize cure rates. In cirrhotic prior null responders, the decision to watch and wait for novel therapies or to use a 4-week lead-in with peginterferon and ribavirin to identify patients more likely to achieve an SVR should only be taken following careful and balanced discussion with the patient. Excerpted from Ramachandrean et al. [35].