At 12:39 PM 9/5/1999, Denis Vulic wrote: >He should avoid all macrolide antibiotics(erythromycin, clarithromycin, >spyramycin). >Azithromycin is an erythromicin derivate and others macrolide antibiotics >are erythromicin derivates ,too. Crossreaction is posible. Has anyone here ever seen an urticarial reaction due to erythromicin? It seems to me that allergic reactions to Biaxin and Zithromax are far more common. Len Leshin, MD, FAAP Corpus Christi, TX mailto: