Antibiotic-associated adverse drug events more common than most doctors realize

A new study underscored the dangers of antibiotic overuse and the reasons doctors must be more cautious when prescribing the drugs in an inpatient setting.

Twenty percent of the hospitalized patients who were prescribed antibiotics experienced at least one antibiotic-associated adverse drug event (ADE), according to the study published in JAMA Internal Medicine.

Researchers from the Johns Hopkins University School of Medicine analyzed the medical records of 1,488 adult patients at Johns Hopkins Hospital who were hospitalized between September 2014 and June 2014 and were prescribed antibiotics for at least 24 hours.  They examined whether the patients developed an adverse drug event, including gastrointestinal, renal, cardiac and neurologic events, during the first 30 days or whether they developed Clostridium difficile infection or incident multidrug-resistant organism infection within 90 days.

They found:

  • The most common reasons to prescribe antibiotics were to treat urinary tract infections, skin and soft tissue infections and community-acquired pneumonia
  • 1 in 5 patients experienced at least one antibiotic-associated ADE
  • 20% nonclinically indicated antibiotic regimens were associated with an ADE, including seven cases of a C diff infection
  • Every additional 10 days of antibiotic therapy was associated with a 3% increased risk of an ADE
  • The most common ADEs within the first 30 days were gastrointestinal, renal, and hematologic abnormalities
  • There were no deaths attributable to any antibiotic-associated ADE

Researchers said many clinicians may not realize the frequency of the complications because the adverse drug events may occur after patients are discharged from the hospital. The findings, they said, underscore the importance of avoiding unnecessary antibiotic prescribing to reduce the harm that can result from antibiotic-associated ADEs.

"Our findings provide quantitative data about the risk of ADEs that clinicians should consider when weighing decisions to initiate or discontinue antibiotic therapy and lend further credence to the importance of antibiotic stewardship to optimize patient safety,” they wrote.