January 3, 2013
TMP-SMX for Skin Infections Resulting in Upswing in
Drug Reactions

In the U.S., adverse drug reactions (ADRs) send more than half a million children a year to physician offices, clinics, and emergency departments. Among the worst offenders are antimicrobial agents.

That’s why researchers sought to examine the rate of ADRs associated with trimethoprim-sulfamethoxazole (TMP-SMX) use in children.

Among their findings in a study published recently in the journal Pediatrics was that most ADRs associated with TMP-SMX occurred during treatment for skin and soft tissue infections (SSTIs).

The researchers performed a retrospective observational study of TMP-SMX ADRs in children between 2000 and 2009 at Children’s Mercy Hospital, a 317-bed, tertiary care, free-standing children’s hospital in Kansas City, MO, that serves a five-state, 100-county region with around 15,000 admissions yearly.

For comparison, they used the Pediatric Health Information System database to estimate the frequency of hospitalizations for TMP-SMX ADRs at 25 tertiary pediatric hospitals. The National Ambulatory Medical Care Survey/National Hospital Ambulatory Medical Care Survey was used to track changes in outpatient prescribing rates.

Of the 109 children diagnosed with a TMP-SMX ADR, 104 were from 2005 to 2009, with the remainder from 2000 to 2004. Most, 58%, had been treated for a SSTIs, followed by 21% for urinary tract infections.

Of the patients with TMP-SMX ADRs, 37% were hospitalized. Those children hospitalized were more likely to have mucous membrane involvement as well as documented fever, vomiting and/or diarrhea than those evaluated and released from emergency departments.

The TMP adverse reactions were in line with national trends, where the incidence of TMP-SMX ADRs more than doubled from 2004 to 2009 at comparable pediatric hospitals, the authors report.

No overall change in TMP-SMX prescribing was detected with national outpatient data, but the percentage of children prescribed TMP-SMX for SSTI increased from 0% to 2% between 2000 and 2004 and from 9% to 17% from 2005 to 2009.

“TMP-SMX ADRs have occurred more frequently coincident with increased prescribing for SSTI,” the authors conclude. “Increased usage alone may explain the increasing trend of TMP-SMX ADRs in children; however drug–disease interaction may play a role and requires further investigation.”

The authors also suggest that the trend of increased usage is likely to continue with clindamycin resistance in common methicillin-resistant Staphylococcus aureus strains.

“We anticipate a continued increase in TMP-SMX prescribing for SSTI. These findings demonstrate the long recognized but possibly forgotten undesired reactions associated with TMP-SMX. Consideration of the indication as well as the potential harm associated with prescribing TMP-SMX is recommended before the initiation of therapy,” they write.

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