What are the guidelines for using oral antibiotics, such as azithromycin, in pediatric patients with gastroenteritis?

Oral Antibiotics for Gastroenteritis in Pediatric Patients

Oral antibiotics are NOT routinely indicated for pediatric gastroenteritis, as most cases are viral and resolve with rehydration alone; however, azithromycin should be used for confirmed Shigella, severe Campylobacter, or bacterial watery diarrhea with dehydration/malnutrition, while ceftriaxone is reserved for severe Salmonella requiring treatment. 1, 2, 3

When Antibiotics Are NOT Indicated

The cornerstone of gastroenteritis management is rehydration, not antimicrobial therapy. 1

• Most gastroenteritis is viral (Rotavirus, Norovirus) and does not benefit from antibiotics 2, 3
• Oral rehydration solution (ORS) is the primary treatment for mild-to-moderate dehydration, with strong evidence supporting its use over antibiotics 1
• Stool PCR detection of bacteria does not automatically warrant treatment, as colonization versus true infection cannot be distinguished without clinical context 2
• Empirical antibiotics without bacterial identification should be avoided in most cases 2, 3, 4

When Antibiotics ARE Indicated

Antibiotics should be reserved for specific bacterial pathogens or high-risk clinical scenarios. 2, 3

Specific Bacterial Pathogens Requiring Treatment:

Shigella (Shigellosis/Dysentery):

• Azithromycin is the preferred antibiotic for Shigella infections 2, 3
• Dosing: 10 mg/kg on day 1, followed by 5 mg/kg/day once daily on days 2-5 (maximum 500 mg day 1, then 250 mg days 2-5) 5
• Treatment reduces duration of illness and bacterial shedding 2

Campylobacter:

• Azithromycin is preferred, but only for severe cases or early in the disease course 2, 3
• Same dosing as above 5
• Treatment is most effective when started within 3 days of symptom onset 3

Salmonella:

• Ceftriaxone or ciprofloxacin are recommended when antibiotic therapy is indicated 2, 3
• Antibiotics are reserved for: severe disease, bacteremia, infants <3 months, immunocompromised patients, or those with sickle cell disease 2, 4
• Routine Salmonella gastroenteritis does NOT require antibiotics, as treatment may prolong carrier state 2

Vibrio cholerae:

• Antibiotics indicated for confirmed cholera 3
• Azithromycin is effective 3

High-Risk Clinical Scenarios:

Empirical antibiotic therapy may be considered while awaiting microbiological results in: 4

• Severely ill children with signs of sepsis or toxic appearance 2, 4
• Immunocompromised patients or those with chronic conditions 4
• Sickle cell disease patients (risk of Salmonella bacteremia) 2
• Infants <3 months with suspected bacterial gastroenteritis 4
• Traveler's diarrhea in specific settings 4
• Bacterial watery diarrhea with dehydration or malnutrition: Recent evidence shows azithromycin reduces day 3 diarrhea (risk difference -11.6%) and 90-day hospitalization/death (risk difference -3.1%) in children with confirmed bacterial etiology 6

Antibiotic Selection Algorithm

For confirmed or highly suspected bacterial gastroenteritis requiring treatment: 2, 3

1. First-line: Azithromycin for Shigella, Campylobacter, or bacterial watery diarrhea with dehydration/malnutrition 2, 3, 6

   • Oral: 10 mg/kg day 1, then 5 mg/kg days 2-5 5

2. For severe Salmonella requiring treatment:

   • Ceftriaxone (parenteral) or ciprofloxacin (oral/IV) 2, 3
   • Reserve for bacteremia, severe disease, or high-risk patients 2

3. Empirical therapy in severe cases (while awaiting cultures):

   • Oral co-trimoxazole or metronidazole for mild-moderate cases 4
   • Parenteral ceftriaxone or ciprofloxacin for severe cases 4

Critical Pitfalls to Avoid

• Do NOT use antimotility drugs (loperamide) in children <18 years with acute diarrhea, as this carries strong evidence of harm 1
• Do NOT treat asymptomatic carriers unless they are food handlers, healthcare workers, or have Salmonella Typhi 1
• Do NOT use antibiotics for routine viral gastroenteritis, as this promotes resistance without benefit 2, 7
• Do NOT delay rehydration while pursuing microbiological diagnosis—ORS should be started immediately 1, 7
• Beware of rising antibiotic resistance in Salmonella, Shigella, and Campylobacter worldwide, which limits therapeutic options 2

Adjunctive Therapies (Not Antibiotics)

• Ondansetron may facilitate oral rehydration in children >4 years with vomiting 1
• Probiotics (Lactobacillus rhamnosus GG, Saccharomyces boulardii) may reduce symptom duration, though recent North American trials showed no benefit 1, 7
• Zinc supplementation (6 months-5 years) in countries with high zinc deficiency or malnutrition 1
• Continue breastfeeding and resume age-appropriate diet immediately after rehydration 1, 7

Resistance Concerns

The development of antibiotic resistance in Salmonella, Shigella, and Campylobacter is a global concern, making judicious antibiotic use essential. 2 This reinforces the importance of limiting antibiotics to confirmed bacterial pathogens or high-risk scenarios where benefits clearly outweigh risks.