Ribavirin dosage in patients with HCV genotypes 2 and 3 who completed short therapy with peg-interferon alpha-2b and ribavirin.

BACKGROUND: The optimal dose of ribavirin to be used in combination with Peg-IFN in patients with HCV genotypes 2 and 3 undergoing short treatment has not been established. AIM: To explore the relationship between starting ribavirin doses, expressed as mg/kg body weight and both rapid viral response at treatment week 4 (RVR) and sustained virological response (SVR) in patients treated for 12-14 weeks with peg-interferon alpha-2b and ribavirin. METHODS: A post hoc analysis of data collected from two multicenter clinical trials was performed. Multiple regression analyses were employed to identify independent baseline and on-treatment predictors of RVR and SVR. For each dose of ribavirin, the empirical estimated probability of response was computed and the continuous exposure index was dichotomized by using a recursive partitioning and amalgamation method. RESULTS: A nonlinear relationship was ascertained between ribavirin dose and RVR, but not SVR. A dose of 15.2 mg/kg was selected as the best splitting value for discriminating RVR vs. non-RVR. Regression analysis identified low baseline viraemia, genotype 2 and high ribavirin dose as independent prognostic factors for RVR. The likelihood of an SVR was not correlated with baseline ribavirin dose, but was independently predicted by adherence to the full dose throughout treatment and normal platelet counts. CONCLUSIONS: Starting high ribavirin doses appears capable of increasing the rate of RVR in patients with HCV genotypes 2 and 3 undergoing short treatment. Maintenance of the full planned dose throughout treatment is essential for achieving optimal SVR rates.

Early discontinuation of ribavirin in HCV-2 and HCV-3 patients responding to Peg-interferon alpha-2a and ribavirin.

Guidelines for the treatment of patients infected with hepatitis C virus of genotypes 2 and 3 (HCV-2 and HCV-3, respectively) recommend a 24-week course of Peg-interferon (Peg-IFN) alpha-2a combined with ribavirin, despite 50% of patients in registration trials attaining a sustained virologic response (SVR) following Peg-IFN alpha-2a monotherapy. The aim of this study was to delineate patient characteristics that might help to identify individuals likely to benefit from ribavirin discontinuation. One hundred and forty-four HCV-2- and HCV-3-infected patients initiated Peg-IFN alpha-2a (180 microg/week) and ribavirin (1000 or 1200 mg/day); those with viral clearance at week 4 were randomized to either Peg-IFN alpha-2a monotherapy (n = 59) or continuing combination therapy (n = 61) until week 12. Overall, all but one patient with a rapid virologic response (RVR) responded by the end of therapy and the overall SVR rates were lower after discontinuation of ribavirin (54%vs 82%; P < 0.001). In RVR patients who discontinued ribavirin, low baseline viraemia helped predict SVR (odds ratio 11.2, 95% CI 2.7-47.1). SVR rates were similar in patients receiving mono- or combination therapy with low (< or =300,000 IU/mL) and intermediate viraemia (86%vs 81% and 70%vs 71%, 86% refers to low viraemic patients receiving monotherapy and 81% to those receiving combination therapy. Similarly, 70% refers to patients with intermediate viraemic levels receiving monotherapy and 71% to those receiving combination therapy), but different in those with high (>700,000 IU/mL) viraemia (37%vs 88%; P = 0.004). Thus in HCV-2- and HCV-3-infected patients, withdrawal of ribavirin and continuation of Peg-IFN alpha-2a monotherapy may be appropriate to attain an SVR, providing viraemia is cleared early during therapy and associated with low baseline viral load. These results warrant future investigations, as discontinuing ribavirin could lead to considerable savings in cost and quality of life related to over-treatment.

A randomized controlled trial of pegylated interferon alpha-2a (40 KD) or interferon alpha-2a plus ribavirin and amantadine vs interferon alpha-2a and ribavirin in treatment-naïve patients with chronic hepatitis C.

We determined whether triple therapy comprising amantadine (AMA), ribavirin (RBV) and either peginterferon (PEG-IFN) alpha-2a or conventional IFN alpha-2a would improve sustained virological response (SVR) rates over dual therapy with IFN alpha-2a and RBV in patients with chronic HCV infection. A total of 362 treatment-naïve patients were randomized to 48 weeks of treatment with: PEG-IFN alpha-2a 180 microg/week (group A) or IFN alpha-2a 3 MU tiw (groups B and C). All patients received RBV 1000 or 1200 mg/day and those in groups A and B received AMA 200 mg/day. SVR was defined as an undetectable HCV RNA after 24 weeks of untreated follow-up. At the end of therapy, 74.4% (95% CI 0.66-0.82) of patients in group A were HCV RNA-negative compared with 42.5% (95% CI 0.33-0.50) of those in group B (P = 0.0001) and 48.8% (95% CI 0.40-0.56) of those in group C. SVR was achieved in a significantly greater proportion of patients in group A compared with groups B and C: 65.3% (95% CI 0.53-0.56), 33.3% (95% CI 0.25-0.41) and 44.6% (95% CI 0.36-0.53; P = 0.0001) respectively. In patients with genotype 1, SVR rates were 55.2, 22.8 and 28.8% with the three regimens respectively. Factors independently associated with SVR were HCV genotype 2 or 3, therapy with PEG-IFN, female gender and age. In treatment-naive patients with chronic hepatitis C, triple therapy with PEG-IFN alpha-2a, RBV and AMA produces higher SVR than dual or triple therapy with conventional IFN alpha-2a.

Efficacy of 5 MU of interferon in combination with ribavirin for naïve patients with chronic hepatitis C virus: a randomized controlled trial.

BACKGROUND: In chronic hepatitis C the schedule of interferon (IFN), 3 MU thrice weekly (tiw) plus ribavirin (1000-1200 mg/daily) needs further evaluation, as IFN dosages >3 MU achieve better responses. AIMS: To compare the efficacy of 5 MU tiw of IFN with (96 patients) or without ribavirin (96 patients) for 12 months in naïve patients, to evaluate the effect of baseline features on the response to therapy, and to determine a reliable point in time during treatment to predict non-response. RESULTS: Sustained virologic response was 20.8% (95% CI 13-29) with IFN monotherapy and 54.2% (95% CI 44-64) with combination (P = 0.0001), the relapse rate 39.4% (95% CI 23-56) and 9% (95% CI 1-16) (P = 0.0007), and the combined rate of sustained biochemical and virologic response 22.7% (95% CI 14-31) and 60.5% (95% CI 50-71) (P = 0.0001), respectively. Patients given combination therapy were more likely to respond regardless of baseline features. Apart from genotype non-1, predictive factors for IFN monotherapy were ineffective in predicting response to combination therapy. Using logistic regression analysis, IFN-ribavirin was the strongest predictor of response (X2 = 21.3; P = 0.0001). Viral persistence at month 3 of therapy was a more accurate predictor than aminotransferase values for non-response to IFN monotherapy but not to combination therapy (positive predictive values of 98 and 82%, respectively). CONCLUSION: In this study, 5 MU of IFN combined with a standard dose of ribavirin has yielded the highest rate of sustained response reported to date. Further dose finding studies are warranted.

A randomized trial of amantadine and interferon versus interferon alone as initial treatment for chronic hepatitis C.

The aim of this study was to compare, in an open-label study, the efficacy and safety of a combination of interferon (IFN) and amantadine (AMA) with that of IFN alone in previously untreated patients with chronic hepatitis C. A total of 200 patients were randomized to 6 MU of IFN-alpha2a 3 times per week, with 200 mg of AMA daily (n = 99) or to an identical dose of interferon alpha2a (n = 101). Patients were treated for 12 months and observed for 6 months' posttreatment. At the completion of treatment, 28.7% of patients in the monotherapy group and 45.5% in the combination group had a virologic response (P =.014). At 6 months' posttreatment, a sustained virologic response was observed in 16.8% (95% CI: 9-23) of patients with IFN alone versus 29.3% (95% CI: 19-37) of patients who were treated with combination therapy (P =.036). In each of the 2 treatments, genotype was the only predictive parameter for a sustained response. At the logistic regression analysis, therapy and genotype were the only 2 parameters with an independent predictive value. In the combination group, at examination of month 3, hepatitis C virus (HCV)-RNA status had a 97.6% (95% CI: 93-102) positive predictive value and a 50% (95% CI: 37-63) negative predictive value for a sustained virologic clearance. A substantial proportion of naïve patients with chronic hepatitis C have an end-of-treatment and end-of-follow-up virologic and biochemical response to a combination of IFN and AMA. This new treatment appears safe and well tolerated.

A study of factors influencing intestinal parasites in dogs.

Coprological examinations were made on 686 owned dogs (23% of the total number of the registered dogs) in a semiurban area of the province of Bologna including the small towns of S. Agata, S. Giovanni in Persiceto, Sala Bolognese and Crevalcore. The results of the coprological tests were evaluated in association with the data obtained from the owners about the origin and the use or function of the animals, veterinary assistance, diet, cohabitation with other dogs, and the presence of gastrointestinal conditions. Prevalence rates were 7.0% for ascarids, 3.6% for tapeworms, 7.1% for coccidia, 2.8% for hookworms, 28.6% for whipworms. On the whole, the animals positive for gastrointestinal parasites were 37.5% of those examined. Multiple linear regression analysis indicated that the presence of gastrointestinal parasites in general was influenced by the use of the animals, veterinary assistance, age, anthelminthic treatments and cohabitation with other dogs. The presence of ascarids appeared to be influenced by age and veterinary assistance; that of cestodes by veterinary assistance; that of coccidia by cohabitation with other dogs; that of whipworms by function, treatments, veterinary assistance and age. None of the variables considered in the analysis could explain the presence of hookworms. Factor analysis grouped the variables considered into 5 factors: the first was associated with veterinary assistance; the second with the animal's function and the presence of whipworms, hookworms and tapeworms; the third with cohabitation, origin and presence of coccidia; the fourth with the presence of fresh meat (cooked, raw or frozen) in the diet, age and positivity for ascarids; the fifth with sex and the presence of gastroenteric conditions.