http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGIC,GGIC:2006-22,GGIC:en&q=define%3achemotherapy
Yes, it is considered a type of chemotherapy. I was told it is called "bioviral therapy" too.
Interferon is a natural biological which your body produces to fight certain viruses (the main reason that there are no generic meds available).
Ribavirin is a chemo medication, often used to treat influenza in children but has been modified to an oral form for HCV.
My very general and maybe wrong understanding is that interferon is a drug made from the concentrated chemicals in the human body found in our immune system.
Infergen is the same chemical except stronger. It is created in the lab and not taken from human samples.
But is interferon chemo? A type of chemo?
Most here are not coinfected so our knowledge of it is limited. Here is a site that might help below. It could be that some info that is relevant to co infected people treating would be different, I don't know. Also you can google Infergen and Interferon and find tons of info on them and the differences between the two but they are both interferon.
http://www.hivandhepatitis.com/hiv_hcv_co_inf/012804feature.html