adorable baby smiling with joy

Peds Calc

Pediatric Reference

Ampicillin Side EffectsComprehensive Pediatric Safety Guide

Ampicillin is usually well tolerated, but monitor for diarrhea, hypersensitivity, hematologic changes, and EBV-associated rash.

5 Categories
7 Clinical Sources
Evidence-Based
Back to Ampicillin Overview

Essential Information

1

Stop the medicine and seek urgent care for hives, swelling, wheeze, or mucosal lesions

2

Call immediately for watery/bloody diarrhea or persistent abdominal cramps

3

Avoid ampicillin in suspected mononucleosis unless benefits outweigh rash risk

Clinical Overview

Counsel families about the difference between benign maculopapular rashes and IgE-mediated allergies, and advise prompt evaluation for severe diarrhea or hepatic symptoms during prolonged therapy.

Side Effect Categories

5 Systems

Gastrointestinal

2 documented effects

Total Sources: 2

Diarrhea / loose stools

Incidence: Common
Onset: Not specified
mild
1 sources
Duration

Not specified

Management

Maintain hydration; consider probiotics if appropriate. Report persistent or bloody stools.

Monitoring Guidelines

Distinguish mild antibiotic-associated diarrhea from C. difficile (watery stools, fever).

1 clinical sources• PubMed • Clinical Guidelines • FDA

Clostridioides difficile–associated diarrhea

Incidence: Rare
Onset: Not specified
severe
1 sources
Duration

Not specified

Management

Stop ampicillin, evaluate urgently, obtain stool testing, initiate targeted therapy.

Monitoring Guidelines

Watch for abdominal pain, fever, dehydration.

1 clinical sources• PubMed • Clinical Guidelines • FDA

Dermatologic / hypersensitivity

2 documented effects

Total Sources: 2

Maculopapular rash (non-IgE, especially with EBV)

Incidence: Common in infectious mononucleosis
Onset: Not specified
mild
1 sources
Duration

Not specified

Management

Stop the drug; supportive care. Document EBV status to avoid future mislabeling as penicillin allergy.

Monitoring Guidelines

Differentiate from hives or systemic reactions.

1 clinical sources• PubMed • Clinical Guidelines • FDA

Immediate hypersensitivity (urticaria, angioedema, anaphylaxis)

Incidence: Rare
Onset: Not specified
severe
1 sources
Duration

Not specified

Management

Discontinue immediately; administer emergency care (epinephrine, airway support, antihistamines).

Monitoring Guidelines

Educate families on emergency response.

1 clinical sources• PubMed • Clinical Guidelines • FDA

Hematologic

1 documented effect

Total Sources: 1

Neutropenia / thrombocytopenia / anemia

Incidence: Rare
Onset: Not specified
moderate
1 sources
Duration

Not specified

Management

Monitor CBC during therapy >14 days; discontinue if significant cytopenias develop.

Monitoring Guidelines

Watch for fever, sore throat, bruising.

1 clinical sources• PubMed • Clinical Guidelines • FDA

Hepatic

1 documented effect

Total Sources: 1

Hepatic dysfunction / cholestatic jaundice

Incidence: Rare
Onset: Not specified
moderate
1 sources
Duration

Not specified

Management

Stop the drug; assess liver function; consult hepatology if needed.

Monitoring Guidelines

Signs include jaundice, dark urine, pruritus, abdominal pain.

1 clinical sources• PubMed • Clinical Guidelines • FDA

Renal / interstitial nephritis

1 documented effect

Total Sources: 1

Acute interstitial nephritis

Incidence: Rare
Onset: Not specified
severe
1 sources
Duration

Not specified

Management

Stop ampicillin, evaluate renal function, consider nephrology consult.

Monitoring Guidelines

Look for fever, rash, eosinophilia, decreased urine output.

1 clinical sources• PubMed • Clinical Guidelines • FDA

Parent Communication Guide

Age-Appropriate Explanations

Infants (0-12 months)

For babies taking Ampicillin, watch for signs of side effects. This medication is generally well-tolerated in infants when used as directed.

Toddlers (1-3 years)

Tell us if there is watery poop, rash, or trouble breathing while you take this medicine.

Children (4-12 years)

Let us know about stomach pain, loose stools, or rashes.

Adolescents (13+ years)

Stop and call for rash, yellowing eyes, or severe diarrhea.

Common Parent Concerns

Q: Loose stools

A: Common and often mild; maintain fluids. Escalate for severe or bloody diarrhea.

When to validate: Immediate evaluation if dehydrated, febrile, or stools contain blood

Q: Rash During Mononucleosis

A: Rashes are common in mono; stopping the drug prevents confusion with true allergies. Document the event clearly.

When to validate: Urgent care for hives, swelling, or mucosal involvement

Clinical Decision Support

Severity Assessment Framework

Guide continuation vs discontinuation based on adverse-effect severity.

Mild
Indicators: Transient diarrhea, Non-itchy maculopapular rash
Action: Continue with monitoring; consider EBV testing if rash occurs
Moderate
Indicators: Persistent diarrhea, Rash with pruritus, Abnormal LFTs
Action: Hold therapy, evaluate clinically, consider switching agents
Severe
Indicators: Anaphylaxis, Stevens–Johnson syndrome, Watery/bloody diarrhea, Acute interstitial nephritis
Action: Stop immediately, provide emergency management, transition to alternative therapy

Treatment Decision Guidelines

Immediate Discontinuation

  • • Anaphylaxis
  • • Severe cutaneous reaction
  • • C. difficile infection
  • • Acute interstitial nephritis

Consider Alternatives

  • • Recurrent moderate GI intolerance
  • • Inability to maintain dosing schedule

Dose Modification

  • • Mild self-limited diarrhea

Clinical References

Ampicillin for Injection — DailyMed•U.S. National Library of Medicine (2025)Label

Frequently Asked Questions

Parent and clinician concerns about Ampicillin