New Guidelines on Antibiotic Prescribing Focus on Shorter Courses

Tara Haelle

April 05, 2021

An antibiotic course of 5 days is usually just as effective as longer courses but with fewer side effects and decreased overall antibiotic exposure for a number of common bacterial conditions, according to new clinical guidelines published today by the American College of Physicians.

The guidelines focus on treatment of uncomplicated cases involving pneumonia, urinary tract infections, cellulitis, chronic obstructive pulmonary disease (COPD) exacerbations, and acute bronchitis. The goal of the guidelines is to continue improving antibiotic stewardship given the increasing threat of antibiotic resistance and the adverse effects of antibiotics.

"Any use of antibiotics (including necessary use) has downstream effects outside of treating infection," Dawn Nolt, MD, MPH, a professor of pediatric infection disease at Oregon Health & Science University in Portland, told Medscape Medical News. Nolt was not involved in developing these guidelines. "Undesirable outcomes include allergic reactions, diarrhea, and antibiotic-resistant bacteria. When we reduce unnecessary antibiotic, we reduce undesirable outcomes," she said.

According to background information in the paper, 1 in 10 patients receives an antibiotic prescription during visits, yet nearly a third of these (30%) are unnecessary and last too long, especially for sinusitis and bronchitis. Meanwhile, overuse of antibiotics, particularly broad-spectrum ones, leads to resistance and adverse effects in up to 20% of patients.

"Prescribing practices can vary based on the type of provider, the setting where the antibiotic is being prescribed, what geographic area you are looking at, the medical reason for which the antibiotic is being prescribed, the actual germ being targeted, and the type of patient," Nolt said. "But this variability can be reduced when prescribing providers are aware and follow best practice standards as through this article."

The new ACP guidelines are a distillation of recommendations from preexisting infectious disease organizations, Nolt said, but aimed specifically at those practicing internal medicine.

"We define appropriate antibiotic use as prescribing the right antibiotic at the right dose for the right duration for a specific condition," write Rachael A. Lee, MD, MSPH, of the University of Alabama Birmingham Medicine, and her colleagues in the article detailing the new guidelines. "Despite evidence and guidelines supporting shorter durations of antibiotic use, many physicians do not prescribe short-course therapy, frequently defaulting to 10-day courses regardless of the condition."

The reasons for this default response vary. Though some clinicians prescribe longer courses specifically to prevent antibiotic resistance, no evidence shows that continuing to take antibiotics after symptoms have resolved actually reduces likelihood of resistance, the authors note.

"In fact, resistance is a documented side effect of prolonged antibiotic use due to natural selection pressure," they write.

Another common reason is habit.

"This was the 'conventional wisdom' for so long, just trying to make sure all bacteria causing the infection were completely eradicated, with no stragglers that had been exposed to the antibiotic but were not gone and now could evolve into resistant organisms," Jacqueline W. Fincher, MD, a primary care physician and president of the American College of Physicians, told Medscape Medical News. "While antibiotic stewardship has been very important for over a decade, we now have more recent head-to-head studies/data showing that in these four conditions, shorter courses of treatment are just as efficacious with less side effects and adverse events."

The researchers reviewed all existing clinical guidelines related to bronchitis with COPD exacerbations, community-acquired pneumonia, urinary tract infections (UTIs), and cellulitis, as well as any other relevant studies in the literature. Although they did not conduct a formal systematic review, they compiled the guidelines specifically for all internists, family physicians and other clinicians caring for patients with these conditions.

"Although most patients with these infections will be seen in the outpatient setting, these best-practice advice statements also apply to patients who present in the inpatient setting," the authors write. They also note the importance of ensuring the patient has the correct diagnosis and appropriate corresponding antibiotic prescription. "If a patient is not improving with appropriate antibiotics, it is important for the clinician to reassess for other causes of symptoms rather than defaulting to a longer duration of antibiotic therapy," they write, calling a longer course "the exception and not the rule."

Acute Bronchitis With COPD Exacerbations

Antibiotic treatment for COPD exacerbations and acute uncomplicated bronchitis with signs of a bacterial infection should last no longer than 5 days. The authors define this condition as an acute respiratory infection with a normal chest x-ray, most often caused by a virus. Although patients with bronchitis do not automatically need antibiotics if there's no evidence of pneumonia, the authors do advise antibiotics in cases involving COPD and a high likelihood of bacterial infection. Clinicians should base their choice of antibiotics on the most common bacterial etiology: Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis. Ideal candidates for therapy may include aminopenicillin with clavulanic acid, a macrolide, or a tetracycline.

Community-Acquired Pneumonia

The initial course of antibiotics should be at least 5 days for pneumonia and only extended after considering validated evidence of the patient's clinical stability, such as resuming normal vital signs, mental activity, and the ability to eat. Multiple randomized controlled trials have shown no improved benefit from longer courses, though longer courses are linked to increased adverse events and mortality.

Again, antibiotics used should "cover common pathogens, such as S pneumoniae, H influenzae, Mycoplasma pneumoniae, and Staphylococcus aureus, and atypical pathogens, such as Legionella species," the authors write. Options include "amoxicillin, doxycycline, or a macrolide for healthy adults or a b-lactam with a macrolide or a respiratory fluoroquinolone in patients with comorbidities."

UTIs: Uncomplicated Cystitis and Pyelonephritis

For women's bacterial cystitis — 75% of which is caused by Escherichia coli the guidelines recommend nitrofurantoin for 5 days, trimethoprim–sulfamethoxazole for 3 days, or fosfomycin as a single dose. For uncomplicated pyelonephritis in both men and women, clinicians can consider fluoroquinolones for 5-7 days or trimethoprim–sulfamethoxazole for 14 days, depending on antibiotic susceptibility.

This recommendation does not include UTIs in women who are pregnant or UTIs with other functional abnormalities present, such as obstruction. The authors also intentionally left out acute bacterial prostatitis because of its complexity and how long it can take to treat.


Methicillin-resistant Staphylococcus aureus (MRSA), which has been increasing in prevalence, is a leading cause of skin and soft tissue infections, such as necrotizing infections, cellulitis, and erysipelas. Unless the patient has penetrating trauma, evidence of MRSA infection elsewhere, injection drug use, nasal colonization of MRSA, or systemic inflammatory response syndrome, the guidelines recommend a 5- to 6-day course of cephalosporin, penicillin, or clindamycin, extended only if the infection has not improved in 5 days. Further research can narrow down the most appropriate treatment course.

This guidance does not apply to purulent cellulitis, such as conditions with abscesses, furuncles, or carbuncles that typically require incision and drainage.

Continuing to Get the Message Out

Fincher emphasized the importance of continuing to disseminate messaging for clinicians about reducing unnecessary antibiotic use.

"In medicine we are constantly bombarded with new information. It is those patients and disease states that we see and treat every day that are especially important for us as physicians and other clinicians to keep our skills and knowledge base up-to-date when it comes to use of antibiotics," Fincher told Medscape Medical News. "We just need to continue to educate and push out the data, guidelines, and recommendations."

Nolt added that it's important to emphasize how to translate these national recommendations into local practices since local guidance can also raise awareness and encourage local compliance.

Other strategies for reducing overuse of antibiotics "include restriction on antibiotics available at healthcare systems (formulary restriction), not allowing use of antibiotics unless there is discussion about the patient's case (preauthorization), and reviewing cases of patients on antibiotics and advising on next steps (prospective audit and feedback)," she said.

The research was funded by ACP. Lee has received personal fees from Medscape and Prime Education, LLC. Fincher owns stock in Johnson & Johnson and Procter and Gamble. Nolt and the article's coauthors have disclosed no relevant financial relationships.

Ann Intern Med. Published online April 5, 2021. Clinical Guidelines

For more news, follow Medscape on Facebook, Twitter, Instagram, YouTube, and LinkedIn


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.