Byetta can be used as a substitute or in addition to insulin.
People are asking whether type 2 diabetes patients using insulin can be switched to Byetta (exenatide). This stems from a recent study showing that exenatide sustains similar glycemic control when substituted for insulin. But this is very misleading.
Patients were poorly controlled to begin with on suboptimal doses of insulin...and didn't improve much when Byetta was started.
In fact, some patients actually deteriorated on Byetta.