How many times have you had this situation? A patient with a urinary tract infection, cellulitis, or pneumonia is given an IV antibiotic dose before discharge. You don’t want to admit the patient, just kick this bactericidal action into high gear.
To be clear, we’re talking about patients who can be immediately discharged with commonly treated infections: cystitis, community-acquired pneumonia, and soft tissue infections like cellulitis, erysipelas, and abscesses. We are not talking about toxic-appearing patients, those who are observed in the emergency room for several hours to monitor disease progression, or those who cannot tolerate oral intake (active vomiting, nonfunctional gastrointestinal tract or aspiration hazard).
Many arguments are used to justify the administration of IV antibiotics before discharge. Perhaps the most cited reason for giving IV antibiotics before discharge is that they “work faster and stronger.” Unfortunately, a multitude of studies run counter to this anecdotal thought. Many commonly used oral antibiotics have excellent absorption and their bioavailability is nearly identical to the IV route. The bioavailability of clindamycin, doxycycline, trimethoprim-sulfamethoxazole, metronidazole and levofloxacin, for example, is over 90%. (Pharmacologist J Pharmacol. 2014;5:83; https://bit.ly/3BottLR.)
Beyond simple bioavailability, several studies have directly compared IV antibiotics to oral antibiotics for various conditions, measuring readmission rates and infection recurrence rates. A review of 25 studies involving 2,488 patients compared oral antibiotics with IV antibiotics for uncomplicated cellulitis, finding no difference in clinical outcomes, including readmission rates. (Cochrane Database System Rev. June 16, 2010;:CD004299; https://bit.ly/3xwjvHc.)
Oral as good as IV
The role of oral antibiotics in other types of infections has also been widely studied. Several randomized controlled trials have shown that oral antibiotics are as effective as IVs in adults with community-acquired pneumonia and urinary tract infections. (Cochrane Database System Rev. October 9, 2014;:CD002109; https://bit.ly/3LhtNAF; Chest. 1996;110:965; Arch Med Intern. 1999;159:53; https://bit.ly/3BKNT2U.) Two randomized, controlled studies have also shown oral and IV equivalence for patients with pediatric pneumonia. (Eur Respir J. 2010;35:858; https://bit.ly/3BIbG3A.)
A retrospective analysis of 30,000 children aged 29 days to 2 years with pediatric UTIs found that 36% received a single dose of IV antibiotics before discharge. Rates of three-day ED visits and ED visits with admission were low in both groups, with no significant difference. (Pediatrics. 2018;142:e20180900; https://bit.ly/3qGUDbN.)
To go further, a review of 15 randomized controlled trials involving 1743 children and adults with UTIs pooled results with no significant differences between oral and IV antibiotics in clinical and bacteriological cure (RR 0.97, CI to 95% 0.81 to 1.17), and no patient had reinfection in either group. (Cochrane Database System Rev. 2007:CD003237; https://bit.ly/3BjXpJ6.)
Cost, time and risk
IV antibiotics are expensive. You might be surprised at the cost if you research the price in your own store. A British study found that the cost of giving IV antibiotics was significantly higher than the cost of the drugs themselves. (Critical care. 2003;7:R184; https://bit.ly/3xuN5ga.) They take longer to administer than oral antibiotics, and administering them also keeps caregivers more busy, freeing them from other patient care duties. Inserting an IV can be cumbersome for some patients and painful for most, and antibiotics do not promote patient ambulation and faster discharge time. With staffing shortages affecting many emergency departments, any chance to reduce nurses’ workloads is welcome.
The administration of IV antibiotics is also not without risk for the patient. Phlebitis and extravasation occurred in less than five percent of cases measured in a non-ED study. (PLoS Med. 2015;12:e1001825; https://bit.ly/3QJhONn; Scand J Infect Dis. 2002;34:512.) Bacteremia may result from peripheral intravenous in up to 0.1% of cases. (Mayo ClinProc. 2006;81:1159.) These numbers are small, but they should be seriously considered for a patient who does not actually need IV antibiotics for a releasable condition.
Another unfortunate point about IV antibiotics is the risk of gastrointestinal disease. We already know that antibiotics predispose patients to higher rates of diarrheal disease and Clostridium difficile, but the parenteral route may be worse. A prospective multicenter cohort study of 247 adult patients showed a significantly higher rate of antibiotic-associated diarrhea with a single dose of IV antibiotics in the emergency department (25.7% versus 12.3%). (Mayo ClinProc. 2006;81:1159.)
Anecdotal thinking holds that patients who are discharged from the ER and do not fill their prescription are at risk of being readmitted unless they receive an intravenous dose in the ER. It’s hard to study, but if we’re inclined to give a dose of antibiotic before discharge to the emergency department, why not give the oral antibiotic that we send home with the patient?
If you’re writing a prescription for doxycycline for cellulitis but want to administer a dose before discharge to the emergency department, for example, skip the vancomycin and give a dose of doxycycline instead. We should reserve broad-spectrum antibiotics for when they are needed in the sickest patients. Giving a patient IV ceftriaxone for a UTI before discharge or vancomycin to treat minor nonpurulent cellulitis is a poor use of resources and contrary to antibiotic management.
IV antibiotics are not so magical. We have a commitment to our patients and the antimicrobial community in which we live. Think before you stick with it next time.
Dr. Briggsis an assistant professor of emergency medicine at the University of Tennessee Medical Center in Knoxville. He is the founder, a podcast host and the editor of EM Board Bombs (https://www.emboardbombs.com), a cross-platform educational tool designed to provide board preparation and focus on what EPs need to know for the practice of emergency medicine. Follow him on Twitter@blakebriggsmd.