What is the difference between immunosuppressive drugs?

A lot. Organ rejection is a complex and not entirely understood immunologic process. Different immunosuppressive drugs are designed to interrupt different parts of this cascade of processes. Each drug has different efficacy and side-effect profiles. Most of the time clinicians employ a combination of multiple drugs and adjust their dosages to maximize efficacy & minimize side-effects.

Related Questions

What are the differences between immunosuppressive drugs and rituxan (rituximab)?

Rituximab. Rituximab is one class of immunosuppresant therapy. It is an chimeric (composed of human and animal) monoclonal antibody directed against a surface marker (cd20) on your b-cells. Your b-cells naturally produce your own body's antibodies to help fight infections. There are other types of immunosuppresants which have different targets than b-cells, such as t-cells, and cytokines such as tnf-alpha. Read more...
Rituximab. All of these are considered immunosuppressive agents since they act by calming down the bodies instigating factor, the immune system which is already acting in an autoimmune fashion. Read more...