What is the recommended treatment for Stenotrophomonas maltophilia infections in pediatric patients?

From the Guidelines

Trimethoprim-sulfamethoxazole (TMP-SMX) at a high dose of 15–20 mg/kg/day of trimethoprim is the recommended treatment for Stenotrophomonas maltophilia infections in pediatric patients. This recommendation is based on the most recent and highest quality evidence available, which suggests that early antimicrobial intervention with high-dose TMP-SMX is effective in treating S. maltophilia pneumonia 1.

Key Considerations

• The dosage of TMP-SMX is crucial, with a recommended dose of 15–20 mg/kg/day of trimethoprim, which is higher than the typical dosage used for other infections.
• In cases where TMP-SMX is not suitable, tigecycline-based treatment may be considered as an alternative, although its use should be individualized and based on the specific clinical scenario 1.
• It is essential to note that in vitro susceptibility may not always predict clinical efficacy of antimicrobial agents in S. maltophilia infections, highlighting the need for close monitoring and adjustment of treatment as necessary 1.

Treatment Approach

• The treatment duration and dosage may need to be adjusted based on the severity and site of infection, as well as the patient's clinical response.
• Combination therapy may be considered for severe infections, particularly in immunocompromised patients, although the evidence for this approach is limited.
• Antimicrobial susceptibility testing should be used to guide treatment whenever possible, as resistance patterns can vary and impact treatment outcomes.

Important Considerations in Pediatric Patients

• The use of TMP-SMX in pediatric patients requires careful consideration of potential adverse effects, particularly in patients with glucose-6-phosphate dehydrogenase deficiency or sulfa allergies.
• Alternative treatments, such as fluoroquinolones or minocycline, may have age-related restrictions and should be used with caution in pediatric patients.

From the Research

Treatment Options for Stenotrophomonas maltophilia Infections in Pediatric Patients

• The recommended treatment for Stenotrophomonas maltophilia infections in pediatric patients is a combination of antibiotics, including trimethoprim-sulfamethoxazole, ciprofloxacin, and/or minocycline 2, 3.
• Trimethoprim-sulfamethoxazole is recognized as the first-line therapy for S. maltophilia infections, but its clinical use is based on good in vitro activity and favorable clinical outcomes, rather than on solid minimum inhibitory concentration (MIC) correlations with pharmacokinetic/pharmacodynamics (PK/PD) and/or clinical outcomes 3.
• Other treatment options, such as levofloxacin and minocycline, have also shown promise, but recent PK/PD studies question the current clinical breakpoints for these agents 3.
• Novel therapeutic options, such as cefiderocol and ceftazidime-avibactam plus aztreonam, have been suggested based on limited but promising clinical data 3.
• Combination therapy with trimethoprim-sulfamethoxazole, levofloxacin, minocycline, or cefiderocol is recommended for severe-to-moderate S. maltophilia infections 3.

Risk Factors and Outcomes

• Risk factors associated with mortality in pediatric patients with S. maltophilia infections include longer hospitalization before infection, septic shock, mechanical ventilation, an indwelling central vein catheter, and prior use of steroids and carbapenems 2.
• The all-cause crude mortality rate for S. maltophilia infections in pediatric patients is high, ranging from 37.5% to 61% 2, 4.
• Ventilator-free days and absolute lymphocyte count prior to acquiring infection are significantly lower in non-survivors than in survivors 4.

Antibiotic Susceptibility and Resistance

• S. maltophilia isolates are often resistant to multiple antibiotics, including trimethoprim-sulfamethoxazole, making treatment challenging 5, 6.
• Minocycline, tigecycline, and colistin have shown good in vitro activity against S. maltophilia isolates, and combination testing of tigecycline and colistin has shown promise 6.
• The development of resistance to trimethoprim-sulfamethoxazole is a growing concern, and alternative treatment options are needed 5.