From the Guidelines
Bactrim DS (trimethoprim-sulfamethoxazole) is not recommended as a first-line treatment for this urinary tract infection caused by Klebsiella pneumoniae. Klebsiella species often have intrinsic or acquired resistance to Bactrim, making it potentially ineffective 1. The optimal treatment would require antibiotic susceptibility testing to determine which antibiotics the specific strain is sensitive to. Common effective options for Klebsiella UTIs include fluoroquinolones (like ciprofloxacin), third-generation cephalosporins, or carbapenems, depending on the resistance pattern. Without susceptibility results, empiric therapy with a fluoroquinolone or cephalosporin would be more appropriate than Bactrim.
According to the American College of Physicians, for men and women with uncomplicated pyelonephritis, clinicians should prescribe short-course therapy either with fluoroquinolones (5 to 7 days) or trimethoprim-sulfamethoxazole (14 days) based on antibiotic susceptibility 1. However, given the potential resistance of Klebsiella pneumoniae to trimethoprim-sulfamethoxazole, a fluoroquinolone or other effective option should be considered. The treatment duration typically ranges from 5-7 days for uncomplicated UTIs to 10-14 days for complicated infections. It's essential to complete the full course of antibiotics even if symptoms improve quickly to prevent recurrence and antibiotic resistance.
In general, the choice of antibiotic should be guided by local resistance patterns and susceptibility testing when possible, as recommended by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases 1. However, the most recent and highest quality study 1 supports the use of short-course antibiotics for uncomplicated UTIs, which should be considered in the treatment of Klebsiella pneumoniae infections.
From the FDA Drug Label
Sulfamethoxazole and trimethoprim have been shown to be active against most strains of the following microorganisms, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section Aerobic gram-negative microorganisms: Escherichia coli (including susceptible enterotoxigenic strains implicated in traveler's diarrhea) Klebsiella species Enterobacter species Haemophilus influenzae Morganella morganii Proteus mirabilis Proteus vulgaris Shigella flexneri Shigella sonnei
Bactrim DS can be used to treat the urine test results showing Klebsiella pneumoniae, as it is effective against Klebsiella species.
- The drug label indicates that sulfamethoxazole and trimethoprim are active against Klebsiella species.
- The MIC values for testing Enterobacteriaceae, which include Klebsiella species, are as follows:
- Susceptible (S): ≤2/38
- Resistant (R): ≥4/76 However, the actual MIC value for the specific Klebsiella pneumoniae strain is not provided in the question, and therefore, it is recommended to perform susceptibility testing to confirm the effectiveness of Bactrim DS against this particular strain 2.
From the Research
Bactrim DS for Urine Test Results
- Bactrim DS, which contains trimethoprim and sulfamethoxazole, can be used to treat urinary tract infections (UTIs) caused by Klebsiella pneumoniae, as shown in the urine test results 3, 4, 5.
- The effectiveness of trimethoprim-sulfamethoxazole (TRS) in treating multidrug-resistant K. pneumoniae UTIs has been demonstrated in several studies, with microbiological eradication and symptomatic relief achieved in all patients 3.
- TRS has been shown to be a cost-effective and efficient second-line treatment for patients with recurrent K. pneumoniae UTIs who have failed at least two prior antibiotic treatments 3.
- The use of trimethoprim-sulfamethoxazole to treat Kp-KPC infections seems promising, with clinical outcomes and tolerability reported in 14 patients infected by Kp-KPC strains susceptible to trimethoprim-sulfamethoxazole 4.
Considerations for Treatment
- The resistance rate of K. pneumoniae to trimethoprim-sulfamethoxazole decreased over the collection period from 26.7% to 16.9% 5.
- The high carrying rates of resistance determinants (sul genes or dfr genes) were the main mechanisms of trimethoprim-sulfamethoxazole resistance isolates 5.
- The development of resistance further limits the use of trimethoprim-sulfamethoxazole in CRE infections 6.
- The combination of trimethoprim-sulfamethoxazole with colistin may be promising for the treatment of CRKP infections 7.