2026 Eastern States Conference

Authors:
Alexandra Meinert, PharmD; Kelsie Ellis, PharmD, BCPPS; Alexandra Medoro, MD 

Objective:  
At the conclusion of the presentation, participants will be able to describe the safety profile of treatment doses of sulfamethoxazole-trimethoprim in patients less than two months of age.  
 
Background:  
Analyze the safety profile of sulfamethoxazole-trimethoprim (SMX-TMP) at a pediatric institution when used in patients less than two months of age or whose post-menstrual age is less than 44 weeks.  
 
Methods:  
Retrospective, single center cohort study including patients who received treatment doses of SMX-TMP (> 5 mg TMP/kg/day) and met the following age restriction: post-natal age < 2 months or post-menstrual age < 44 weeks. 
Evaluated the incidence of kernicterus, hyperbilirubinemia, hepatic dysfunction, acute kidney injury, thrombocytopenia, leukopenia, hyperkalemia, hypoglycemia, hyponatremia, anaphylaxis, or discontinuation of SMX-TMP prior to intended stop date. Data were obtained via retrospective chart review.
Data was analyzed via descriptive statistics. Non-parametric continuous data represented via median and interquartile range; nominal data represented as frequency and percentage.  
 
Results:  
In this study, 36 patients met inclusion criteria and were included. 
During the study period, eight patients (22.2%) experienced at least one adverse drug reaction. The most prevalent adverse drug reaction was transaminitis which was present in 5/15 (33.3%) patients. No patients were diagnosed with kernicterus, but one patient (2.8%) did experience hyperbilirubinemia that resolved after four days of phototherapy.  
Two patients (5.6%) discontinued SMX-TMP prior to the intended stop date due to an intolerable adverse drug reaction. One patient was noted to have had an apparent allergic reaction, and the other patient experienced hyponatremia and acute kidney injury.  
 
Conclusion:  
SMX-TMP was relatively well tolerated in this study. Few patients discontinued treatment due to adverse effects, most patients did not experience an adverse drug reaction, and no serious side effects (like kernicterus) were observed.  

Self-Assessment Question:
What was the most common adverse drug reaction observed in this study? 
A) Kernicterus
B) Hyperbilirubinemia 
C) Transaminitis 
D) AKI