A recent systematic review published in Pharmacotherapy compared the efficacy of short and long courses of antibiotics to treat bacterial infections.
Antimicrobial stewardship programs are growing in all parts of the world because of the increased risk of antibiotic resistance. There are many factors that can contribute to the emergence of resistant bacteria; thus, best practices need to be continuously updated. One strategy to reduce the burden of antibiotics on the microbiome is to reduce treatment durations.
Shortening treatment may reduce antibiotic exposure and resistance
Evidence suggesting shorter courses of antibiotics to treat bacterial infections is growing. Nevertheless, there is intense opposition among prescribers to shorten the course of antibiotic treatment. The belief that shortening a course of antibiotics can lead to bacterial resistance is widely accepted by clinicians and patients. However, shorter durations of treatment reduces the exposure to antibiotics and can possibly reduce the incidence of resistance.
Two doctors of pharmacy from Philadelphia, Pennsylvania, conducted a systematic review of studies comparing short and long courses of antibiotics in six common infections. Their results were published in Pharmacotherapy.
Comparing treatments for community-acquired pneumonia
Several studies have compared fluoroquinolone treatment durations for community-acquired pneumonia (CAP) where the shorter duration was as effective as the longer duration. Amoxicillin showed similar results at an equal dose between three and eight days of treatment. Azithromycin given for three days was also equal in effectiveness as the traditional five-day treatment.
In the early 2000s, treatment duration recommendations for hospital-acquired or ventilator-associated pneumonia (HAP/VAP) was shortened from 14 to 21 days to eight to 15 days. Longer durations may still be required for very resistant bacteria. Researchers have noticed similar mortality between the eight and 15-day treatment durations.
Comparing treatments for intra-abdominal infections
Intra-abdominal infections require between four to seven days of treatment, but traditionally antibiotics are prescribed for longer durations, extending beyond the resolution of signs and symptoms. The STOP-IT trial compared long and short regimens for treating intraabdominal bacterial infections and the primary endpoints (death and infectious complications) were similar between the four-day course and the duration extending two days after signs and symptoms resolved.
Comparing treatments for skin infections
Skin and soft tissue infections (SSTIs) are usually treated by draining and cleaning and a course of antibiotics. Researchers studied whether there was a need for antibiotic treatment following drainage and cleaning. Considering the high success rate when antibiotics were not given, shorter courses of antibiotics may be considered for SSTIs. Guidelines recommend a duration of five days over ten days in uncomplicated skin infections, but more studies are required to confirm these findings.
Comparing treatments for urinary tract infections
Depending on the drug class, a different treatment duration is recommended for treating uncomplicated urinary tract infections (UTIs). Fosfomycin resolves a UTI in one dose, whereas nitrofurantoin requires a minimum of five days and sulfamethoxazole/ trimethoprim and fluoroquinolones require three days. Beta-lactam antibiotics may require more time to treat a UTI (between three and seven days) due to its pharmacodynamic properties.
For complicated UTIs, the fluoroquinolone class is the only one with studies suggesting shorter courses may be sufficient. Levofloxacin for five days was as efficacious as ciprofloxacin for ten days and ciprofloxacin for seven days was as efficacious as the same drug and dose for 14 days. Nevertheless, further studies are required before recommending shorter durations for complicated UTIs.
Shorter courses of antibiotics may be prescribed for bacterial infections
In conclusion, evidence suggests that shorter courses of antibiotics can be prescribed for treating bacterial infections. Prescribers are typically giving antibiotics for a treatment duration that exceeds the Infectious Diseases Society of America’s recommendations. The strategy of reducing the treatment duration of antibiotics where applicable can help slow down the emergence of resistant bacteria.
Jessica Caporuscio, PharmD
Reference: Hanretty AM, Gallagher JC. Shortened Courses of Antibiotics for Bacterial Infections: A Systematic Review of Randomized Controlled Trials. Pharmacotherapy. 2018.