TMP-SMX should not be prescribed to infants of which age group?

TMP-SMX should not be prescribed to infants of which age group?

• A. 0-2 months
• B. 3-6 months
• C. 6-12 months
• D. 12-24 months

Answer: (A)

Infants younger than two months should not receive trimethoprim-sulfamethoxazole because of the risk of kernicterus. In neonates, sulfonamides can displace bilirubin from albumin, increasing free bilirubin levels. The immature liver may struggle to conjugate bilirubin, and the blood-brain barrier is more permeable at this age, raising the chance that bilirubin deposits in the brain and causes neurologic injury. As bilirubin metabolism matures around two months, the risk decreases, making TMP-SMX acceptable in older infants when indicated.

Infants younger than two months should not receive trimethoprim-sulfamethoxazole because of the risk of kernicterus. In neonates, sulfonamides can displace bilirubin from albumin, increasing free bilirubin levels. The immature liver may struggle to conjugate bilirubin, and the blood-brain barrier is more permeable at this age, raising the chance that bilirubin deposits in the brain and causes neurologic injury. As bilirubin metabolism matures around two months, the risk decreases, making TMP-SMX acceptable in older infants when indicated.