Astemizole
Astemizole (marketed under the brand name Hismanal, developmental code R43512) was a second-generation antihistamine drug that has a long duration of action. Astemizole was discovered by Janssen Pharmaceutica in 1977. It has been withdrawn from the market in most countries because of rare but potentially fatal side effects (QTc interval prolongation and related arrhythmias due to hERG channel blockade).
NS5B inhibitor
Comparing virological response of NS5B inhibitors to previous therapy of chronic hepatitis C with the combination of interferon and ribavirin, it was possible to observe a significant difference in efficacy and safety. The efficacy rate of interferon plus ribavirin varied within 44-46% while it increases up to 90% by direct acting antivirals such as NS5B inhibitors/ Data on the frequency of side effects may vary between researches for both drug categories. Nevertheless, there is a significant difference between the safety profiles of NS5B inhibitors, particularly sofosbuvir and the combination of interferon and ribavirin. Comparing interferon containing therapies, sofosbuvir does not cause neutropenia, thrombocytopenia, or any other serious adverse effects. Common side effects associated with sofosbuvir are headache, tiredness, insomnia, dizziness, itching, infections of upper respiratory tract, rashes, back pain, anemia, and lymphopenia. With the advent of direct acting antivirals, the duration of the hepatitis treatment has also been impressively reduced. Severity of adverse effects is strongly associated with duration of therapy and the dose used for hepatitis C treatment. Therefore, direct actung antivirals have become the initial treatment ised for most patients with chronic hepatitis C.