From the Guidelines
Trimethoprim-sulfamethoxazole (TMP/SMX) is the preferred treatment regimen for documented Stenotrophomonas maltophilia pneumonia. The dose of TMP/SMX for treatment of S. maltophilia pneumonia is similar to the treatment of P. jirovecii pneumonia 1. This recommendation is based on the guidelines from the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) 1.
Key Considerations
- The selection of antimicrobial treatment should be based on the known toxicity profiles of these compounds and, if present, known resistance patterns 1.
- Response to antimicrobial treatment should be clinically assessed on a daily basis 1.
- Imaging studies to re-assess treatment response should generally not be ordered earlier than after 7 days of antimicrobial treatment 1.
- In patients with lack of clinical improvement, CT scan should be repeated after 7 days of treatment 1.
Treatment Approach
- TMP/SMX is the first-line treatment for Stenotrophomonas maltophilia infections, and the dose should be adjusted according to the severity of the infection 1.
- For severe infections, higher doses may be used, and treatment duration may extend to 2-3 weeks.
- In patients with sulfa allergies or TMP-SMX resistance, alternative options include fluoroquinolones, minocycline, or combination therapy with ticarcillin-clavulanate plus an aminoglycoside.
- Susceptibility testing should guide therapy whenever possible, as resistance patterns can vary 1.
From the Research
Treatment Options for Stenotrophomonas Maltophilia Infections
- Trimethoprim-sulfamethoxazole (SXT) is recognized as the first-line therapy for S. maltophilia infections, based on good in vitro activity and favorable clinical outcomes 2.
- However, its clinical use is based on limited minimum inhibitory concentration (MIC) correlations with pharmacokinetic/pharmacodynamics (PK/PD) and/or clinical outcomes 2.
- Other treatment options like levofloxacin (LVX) and minocycline (MIN) have been used, but recent PK/PD studies question the current clinical breakpoints for these agents 2.
- The Infectious Diseases Society of America (IDSA) recommends using these agents only as part of a combination therapy 2.
- Novel therapeutic options such as cefiderocol (FDC) and ceftazidime-avibactam plus aztreonam (CZA-ATM) are suggested, based on limited but promising clinical data 2.
Alternative Therapies
- Levofloxacin is a reasonable alternative to TMP-SMX for the treatment of bloodstream and lower respiratory tract infections caused by S. maltophilia, with similar mortality risk and fewer hospital days 3.
- Ciprofloxacin, ceftazidime or ceftriaxone, and ticarcillin/clavulanate, alone or in combination with other antibiotics, may be considered as alternative options beyond co-trimoxazole 4.
- SmeD overexpression plays a role in levofloxacin resistance in S. maltophilia, and the use of triclosan can increase the growth of a levofloxacin-susceptible isolate in the presence of levofloxacin 5.
Combination Therapy
- Combination therapy of SXT, LVX, MIN, or FDC, or monotherapy with CZA-ATM are recommended therapeutic options for severe-to-moderate S. maltophilia infections 2.
- Certain combinations of antibiotics are synergistic and may be appropriate for patients harboring resistant organisms or with life-threatening infections 6.