#EMconf: Antibiotic Side Effects

Side Effects of Common Antibiotics


  • Erythema Multiforme that ranges from EM Minor to Stevens-Johnson Syndrome to Toxic Epidermal Necrolysis 
  • Treatment: stop offending agent, supportive care, possible admission to burn unit


  • Tendonitis and tendon rupture (Achilles) especially for age >60, corticosteroids, renal insuffieiency, previous tendon injury
  • Avoid in benzodiazepine dependent patients;  can cause acute withdrawal by displacing the benzo from its binding site


  • Ototoxicity: Cochlear damage by free oxygen radicals causes permanent impairment (Macrolides: temporary impairment)
  • Nephrotoxicity: ATN and non-oliguric renal failure (reversible), more risk with frequent or very high doses, duration >3 days, and older age


  • Liver injury: 1-2x increase in AST/ALT with return to baseline within 2 weeks after cessation of antibiotic and Acute Idiosyncratic Liver Injury: 2-12x increase in AST/ALT over baseline with fever and jaundice. NOT associated with liver failure 
  • Most common antibiotic to cause C. Difficile colitis


  • Serotonin Syndrome: can occur when combined with another serotonergic drug (SSRI, MAOI, TCAs) 




References: 1. Tintinalli, Judith E., MD. "Antimicrobials." Emergency Medicine: A Comprehensive Study Guide. New York: McGraw-Hill, 2015. 1346-350. Print. 2. Holubar, Marisa, MD. "Antibiotic Stewardship." UpToDate, 1 May 2014. Web. 5 May 2017.