What is the difference between weight-based and fixed dose of pegylated interferon?

Different meds: Peg-intron (alpha 2b) is given as a weight based medication. Pegasys (peginterferon alfa 2a) (alpha 2a) is given as a fixed dose. The difference has to do with the distribution throughout the tissues and fats of the body. Most docs think the 2 are comparable clinically as long as they are dosed appropriately. If using for treatment of hepatitis c, they should be used in combination with 1 or 2 other meds for best results.

Interferon: Weight based means that the dose is adjusted for the milligrams per kilogram of the patient whereas a fixed dose simply means everybody, no matter age or weight or gender, gets the exact same dose.