What is the Difference Between Interferon and Peginterferon?

The main difference between interferon and peginterferon lies in the presence of a molecule called polyethylene glycol (PEG) in the latter. By attaching a PEG molecule to the interferon, the half-life of the drug is prolonged, allowing it to stay in the body (specifically the blood) for a longer period.

There are two main types of pegylated interferons: peginterferon alfa-2a and peginterferon alfa-2b. They differ in the size and nature of their PEG moiety, as well as their pharmacokinetic and pharmacodynamic profiles. However, their pharmacodynamic parameters appear to be similar.

Studies have consistently demonstrated that peginterferon monotherapy is superior to standard interferon monotherapy, even in patients with advanced fibrosis. In combination with ribavirin, peginterferon alfa-2b has been shown to be more effective than standard interferon alfa-2b for the initial treatment of hepatitis C in HIV-infected patients.

Comparative Table: Interferon vs Peginterferon

Interferon and peginterferon are both types of interferons used in the treatment of hepatitis C virus (HCV) infection. The main difference between them is the presence of a molecule called polyethylene glycol (PEG) in peginterferon, which prolongs the drug's activity in the body. Here is a table comparing the differences between interferon and peginterferon:

There are two types of peginterferon: alpha-2a (PEG-IFN-α2a) and alpha-2b (PEG-IFN-α2b). The difference between these two types lies in the structure of the polyethylene glycol moiety and the position of pegylation. PEG-IFN-α2b is obtained by the covalent linking of a linear 12 kDa PEG chain to IFN-α2b, while PEG-IFN-α2a has a 40 kDa polyethylene glycol moiety, comprising two 20 kDa chains. These differences result in PEG-IFN-α2b being a pro-drug that releases IFN-α2b, which behaves similarly to standard IFN-α in terms of its receptor binding, antiviral activity, and pharmacokinetic properties.