Which antibiotic is commonly used to treat pertussis in infants older than 1 month?

Which antibiotic is commonly used to treat pertussis in infants older than 1 month?

• A. Azithromycin
• B. Erythromycin
• C. Amoxicillin
• D. Cephalexin

Answer: (B)

Treat pertussis with antibiotics that effectively target the bug in the respiratory tract to shorten illness and reduce spread. Macrolides are the go-to class because they inhibit the bacterial ribosome, blocking protein synthesis and helping clear Bordetella pertussis. In infants older than one month, erythromycin has a long history of use and proven effectiveness against pertussis in this age group, with dosing that fits pediatric practice. Amoxicillin and cephalexin don’t reliably treat pertussis since they’re beta-lactams that don’t target B. pertussis, so they aren’t appropriate choices for this infection. Although azithromycin is also effective and commonly used today due to convenient dosing and tolerability, erythromycin is the classic option reflected in many pediatric guidelines for infants older than one month.

Treat pertussis with antibiotics that effectively target the bug in the respiratory tract to shorten illness and reduce spread. Macrolides are the go-to class because they inhibit the bacterial ribosome, blocking protein synthesis and helping clear Bordetella pertussis. In infants older than one month, erythromycin has a long history of use and proven effectiveness against pertussis in this age group, with dosing that fits pediatric practice. Amoxicillin and cephalexin don’t reliably treat pertussis since they’re beta-lactams that don’t target B. pertussis, so they aren’t appropriate choices for this infection. Although azithromycin is also effective and commonly used today due to convenient dosing and tolerability, erythromycin is the classic option reflected in many pediatric guidelines for infants older than one month.