What are oral antibiotics comparable to Ampicillin (Ampicillin)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: May 28, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Amoxicillin is the most comparable oral medication to ampicillin, with similar spectrums of activity against many gram-positive and some gram-negative bacteria. According to the guidelines provided by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America 1, amoxicillin is listed as a preferred oral therapy for several pathogens, including Streptococcus pneumoniae, Haemophilus influenzae, and Group A Streptococcus. The guidelines recommend amoxicillin dosing of 90 mg/kg/day in 2 doses or 45 mg/kg/day in 3 doses for children with Streptococcus pneumoniae infections 1.

Key Points

  • Amoxicillin has better absorption from the gastrointestinal tract (about 75-90% absorbed) compared to oral ampicillin (35-50% absorbed) 1
  • Amoxicillin can be taken with food, whereas ampicillin absorption is reduced by food
  • Common adult dosing for amoxicillin is 250-500mg three times daily or 875mg twice daily, depending on the severity of infection
  • For children, dosing is typically 20-90mg/kg/day divided into 2-3 doses
  • Treatment duration varies by infection type, usually 7-14 days
  • Amoxicillin-clavulanate (Augmentin) combines amoxicillin with a beta-lactamase inhibitor, making it effective against more resistant bacteria

Considerations

  • Patients with penicillin allergy should avoid amoxicillin due to cross-reactivity
  • Side effects of amoxicillin include diarrhea, nausea, and rash
  • The guidelines recommend the shortest effective duration of treatment to minimize exposure to antimicrobials and minimize the selection for resistance 1

From the Research

Oral Medicine Comparable to Ampicillin

  • Levofloxacin is a fluoroquinolone antibacterial agent with a broad spectrum of activity against Gram-positive and Gram-negative bacteria and atypical respiratory pathogens, and has been shown to be effective in the treatment of infections of the respiratory tract, genitourinary tract, skin and skin structures 2.
  • Amoxicillin-clavulanic acid is a combination product that has been used as empiric therapy for many infections, but its use is often limited by gastrointestinal side effects, including Clostridium difficile infection 3.
  • Other oral agents, such as cefpodoxime, cefditoren, and azithromycin, have been shown to have activity against certain Gram-positive and Gram-negative bacteria, but their effectiveness can vary depending on the specific infection and the presence of resistance 4.
  • Vancomycin, doxycycline, and fusidic acid have been shown to be effective against certain non-spore-forming Gram-positive bacilli, including Corynebacterium species 5.
  • Novel antibiotics, such as cefiderocol, a new cephalosporin, have been studied and show promising results against Pseudomonas aeruginosa, a common nosocomial pathogen 6.

Comparison to Ampicillin

  • Levofloxacin has been shown to be as effective as amoxicillin-clavulanic acid in the treatment of certain infections, such as community-acquired pneumonia 2.
  • Amoxicillin-clavulanic acid has been compared to other oral agents, such as cefpodoxime and cefditoren, and has been shown to have similar or better activity against certain bacteria 4.
  • The choice of oral medicine comparable to ampicillin will depend on the specific infection, the presence of resistance, and the patient's individual needs and medical history.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.