Explore the critical side effects and toxicities associated with antibiotics in this comprehensive lecture. Delve into major adverse reactions including allergic responses, diarrhea, C. diff colitis, QT prolongation, and interactions with warfarin. Gain insights into the cross-reactivity between penicillins and cephalosporins, and learn how to effectively use serum drug levels for titrating vancomycin and aminoglycosides. Cover key topics such as antibiotic-associated diarrhea, important antibiotic toxicities, and specific considerations for aminoglycosides to enhance your understanding of safe antibiotic use in clinical practice.