Drug Name Azithromycin Drug Class Antibiotic Risk minimization type Direct Healthcare Professional Communication DHPC Safety communication Specialty (Theraputic area) Infectious disease Risk Risk of Hematological Relapses and Deaths Associated with Long-Term Use of Azithromycin Following Hematopoietic Stem Cell Transplant . increased rate of relapses hematological malignancies and mortality in hematopoietic stem cell transplantation patients. safety communication Dear Healthcare provider letter DHPC