Prescriptions

I am assuming that CRNAs can prescribe class II and III drugs, how else do they put the patient under. But is there license to extended to the follow-up pain management for a procedure? Are their any limitations (except for the moral ones) that are put on CRNAs on there prescription writing? I know that an Anesthesiologist can write for antibiotics, or anything they feel is appropriate, is that also extended to the CRNAs?