What to do for a 10-month-old baby with Acute Otitis Media (AOM) who develops diarrhea after starting Amoxicillin (amoxicillin)?

Management of Diarrhea in a 10-Month-Old on Amoxicillin for AOM

Continue the amoxicillin as prescribed and manage the diarrhea supportively, as this is an expected and generally mild adverse effect that does not warrant discontinuation of therapy in most cases. 1, 2

Understanding Amoxicillin-Associated Diarrhea

• Diarrhea is a common and expected adverse effect of amoxicillin therapy, occurring in approximately 25% of treated children compared to 15% in placebo groups—a difference of only 10% 1
• The American Academy of Pediatrics acknowledges that amoxicillin causes adverse events (primarily diarrhea and rash) in approximately 5% more patients than placebo, but these events are generally mild and do not outweigh the benefits in confirmed AOM 2
• This diarrhea typically represents antibiotic-associated disruption of normal gut flora rather than a serious allergic reaction or Clostridioides difficile infection in the first 24-48 hours 3

When to Continue vs. Discontinue Amoxicillin

Continue amoxicillin if:

• The diarrhea is mild to moderate (3-5 loose stools per day) without blood 3
• The child remains well-hydrated and is feeding normally 3
• There are no signs of severe allergic reaction (no rash, no facial swelling, no difficulty breathing) 3
• The child is not showing signs of dehydration (adequate urine output, moist mucous membranes, normal activity level) 3

Consider discontinuation and reassessment if:

• Watery and bloody stools develop (with or without stomach cramps and fever), which could indicate Clostridioides difficile-associated diarrhea, though this typically occurs later in treatment or even 2+ months after completion 3
• Signs of severe cutaneous adverse reactions appear (skin rash, mucosal lesions, or other signs of hypersensitivity) 3
• The child develops signs of dehydration despite oral rehydration efforts 3
• Severe, persistent diarrhea (>10 watery stools per day) occurs 3

Supportive Management Strategies

• Maintain adequate hydration with oral rehydration solutions or continued breastfeeding/formula feeding 3
• Probiotics may be considered to reduce antibiotic-associated diarrhea, though this is not specifically mandated by AAP guidelines 2
• Monitor for diaper dermatitis, which occurred in 51% of amoxicillin-treated children versus 35% in placebo groups, and apply barrier creams prophylactically 1
• Ensure the full 10-day course is completed (appropriate for a 10-month-old with AOM) to prevent treatment failure and bacterial resistance 1, 4

Critical Reassessment Timeline

• Reassess at 48-72 hours to evaluate both the AOM response and tolerability of the antibiotic 1, 4
• If the AOM symptoms worsen or fail to improve by 48-72 hours AND the diarrhea is problematic, consider switching to a second-line agent such as ceftriaxone (which avoids the clavulanate component that worsens GI side effects) rather than amoxicillin-clavulanate 1, 5
• Document the diarrhea as an adverse effect for future antibiotic selection, though mild diarrhea alone is not considered a penicillin allergy 1

Common Pitfalls to Avoid

• Do not prematurely discontinue amoxicillin for mild diarrhea, as this increases treatment failure risk (21% with inadequate treatment versus 5% with complete treatment) 4
• Do not switch to amoxicillin-clavulanate for treatment failure if diarrhea is already problematic, as the clavulanate component significantly increases GI adverse effects 1, 5
• Do not confuse antibiotic-associated diarrhea (common, mild, self-limited) with true penicillin allergy, which would present with urticaria, angioedema, or anaphylaxis 3
• Ensure parents understand that diarrhea is expected and does not indicate treatment failure or allergy in most cases 2, 3