Antiviral therapy is effective in more than half of infected patients, but the actual rate of sustained viral response depends on viral, host, and adherence factors. hepatitis C is the one of the leading causes of chronic liver disease and is the single most common indication for liver transplantation [13]. Antiviral therapy is effective in more than half of infected patients, but the actual rate of sustained viral response depends on viral, host, and adherence factors. Viral and host factors tend to be nonmodifiable, whereas interventions may increase adherence. The current standard of care for hepatitis C therapy is the combination of pegylated interferon and ribavirin [4]. Sustained Mitochonic acid 5 viral response for antiviral therapy is about 55% [5,6]. However, adverse effects from antiviral therapy directly affect treatment adherence and can decrease the likelihood of a sustained viral response. These complications can severely compromise quality of life [7]. Both interferon and ribavirin are associated with signature effects that are predictable, manageable, and improve with dose modification or discontinuation [8]. Rarely is an adverse effect from hepatitis C antiviral therapy permanent. Adverse effects can arise from both interferon and ribavirin, and may lead to treatment termination and dose modifications in 10% to 15% and 32% to 42% of patients, respectively [5,6,9]. When interferon and ribavirin Mitochonic acid 5 doses are reduced by a certain threshold, the sustained viral response may also decrease [10]. For instance, the results of a recent study COLL6 by Reddy et al. [11] demonstrated the sustained viral response is 34% when a patients cumulative ribavirin dose decreases below 60%. An understanding of the antiviral adverse effects is essential to effectively deal with adverse effects in a timely manner. The goal during therapy is to maximize the likelihood of achieving a sustained viral response while improving tolerability and maintaining quality of life. Providers should discuss the potential issues with patients and with their social support. During clinic follow-up, patients should be queried about treatment adverse effects. Many times, the adverse effects can accumulate over time and lead to early treatment discontinuation. The current paper reviews the most frequent adverse effects associated with hepatitis C therapy, and proposes interventions to ameliorate complications. The adverse effects from pegylated interferon and ribavirin are considered separately. == Pegylated Interferon == The efficacy and therapeutic value of hepatitis C treatment is dependent on the degree of tolerability and adherence to the drugs, which in turn are related to the management of the side effects. The frequency and number of side effects related to interferon therapy are common, with most clinical trials reporting at least one interferon-related adverse effect in 95% of the patient group [5,10,12]. The most frequently reported adverse effects from interferon include constitutional, hematologic, neuropsychiatric, and endocrinologic complications (Table1). The onset of the adverse effects differ. The onset can be from minutes after the interferon injection, to months (Table2). == Table 1. == Common adverse effects, frequency, and treatment of ribavirin plus interferon ANCabsolute neutrophil count,GCSFgranulocyte colony-stimulating factor,Hbhemoglobin,NSAIDSnonsteroidal anti-inflammatory,SSRIselective serotonin reuptake inhibitor == Table 2. == Time to onset of common adverse effects == Constitutional Effects == The most common adverse effects from interferon are constitutional symptoms. The severity of these side effects is inversely related to the amount of time after the interferon injection. Fatigue, headache, and fever were each reported in about 50% to 60% of treated patients [6,9,12]. Constitutional effects can manifest early during therapy, even after the first dose of interferon [12]. However, several constitutional effects (e.g., fever) resolve or wane after the first several injections. Certain precautions can assist with Mitochonic acid 5 the effects, such as maintaining adequate Mitochonic acid 5 hydration and light to moderate exercise. The suggested intake of water in ounces is equivalent to half the patients body weight in pounds. To prevent interferon therapy from interfering with work, injections should occur on Fridays. As a result, most of the constitutional effects will occur on Saturday. By Monday, treated patients tend to feel better. The use of acetaminophen or ibuprofen before the injection can also ameliorate many of the.