Management of Drug Interactions and Side Effects in Patients with Chronic Hepatitis C Receiving Triple Therapy

Abstract

Purpose: Triple therapy with pegylated interferon (IFN), ribavirin (RIB), and boceprevir (BOC) has been shown to increase sustained virological response in patients with chronic hepatitis C. However, health care providers are faced with the management of drug interactions and side effects of this new therapeutic regimen. The purpose of this research study is to collect data regarding the management of the drug interactions and side effects in patients with chronic HCV receiving this therapy. Methods: A prospective chart review of 26 patients with hepatitis C, receiving triple therapy with pegylated interferon, ribavirin, and boceprevir was conducted. Pegylated IFN, RIB dosages, hemoglobin (Hgb), white blood cell count (WBC), and platelets levels were reviewed. Anemia was defined as either symptomatic decreases from baseline Hgb or Hgb < 10.5 g/dL, while leukopenia was defined as WBC < 4.0 K/mm3. Side effects were recorded at the time of the visit. Concomitant medication changes occurred at the initial visit and were monitored during the initial 24 weeks of therapy. Results: Mean age of this cohort (17 white, five African-American, four Hispanic) was 57.9 ± 4.9 years. Average initial viral load (VL) was 4.04 million (m) (0.002 - 22.0 m); initial platelet count was 164 K ± 42 K; initial fibrosis stage was 2.5 ± 0.94. Initially, patients received pegylated interferon (IFN) [(IFN 180 μg, n=20), (150 μg n=2), (135 μg, n=2), 120 μg, n=2)], [ribavirin (1200 mg, n = 18), (1000 mg, n=4), (800 mg, n=3), (600 mg, n=1)], and boceprevir 800 mg orally, three times per day. Laboratory values decreased during the initial 24 weeks (Hgb, 15.4 to 10.9 g/dL), (platelets 164 to 124K), and (WBC, 5.9.to 2.7 K/mm3). The average amount of pegylated interferon and ribavirin received also decreased (IFN 127 μg and ribavirin 682 mg) at week 24. Three patients relapsed >24 weeks, and two patients were detected at 24 weeks. The side effects included: flu-like syndromes (n=19), rash (n=17), diarrhea (n=2), nausea/vomiting (n=10), anemia (n=26), and leukopenia (n=26). The most frequent drug interactions requiring discontinuations, reductions, or close monitoring involved the following: phosphodiesterase inhibitors, tramadol, and simvastatin. Conclusion: The majority of patients in this small cohort cleared their virus. Reductions in pegylated interferon and ribavirin were common among the HCV patients with fibrosis; however, virological response was 81% in patients who did not fail or discontinue medications. Initial changes in medication were common in this patient cohort.Table 1