Ampicillin effectively combats several bacterial respiratory infections. However, its use is guided by bacterial sensitivity testing.
Ampicillin is frequently prescribed for:
- Pneumonia: Especially community-acquired pneumonia caused by susceptible Streptococcus pneumoniae and Haemophilus influenzae. Dosage depends on the severity and patient factors. Bronchitis: Acute bronchitis caused by susceptible bacteria may respond to ampicillin. However, many cases are viral, rendering antibiotics ineffective. Sinusitis: Bacterial sinusitis, typically involving Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis, might benefit from ampicillin, but only after confirmation of bacterial infection. Tonsillitis/Pharyngitis: Ampicillin targets Streptococcus pyogenes (Group A Streptococcus), the cause of strep throat. Proper diagnosis is critical before prescribing.
Important considerations:
Always obtain a bacterial culture and sensitivity test: This ensures the bacteria causing the infection are susceptible to ampicillin. Treatment with an inappropriate antibiotic can worsen the infection. Follow prescribed dosage and duration carefully: Incomplete treatment courses increase the risk of antibiotic resistance. Report any adverse reactions immediately: Common side effects include diarrhea, rash, and nausea. More serious reactions require immediate medical attention. Ampicillin isn’t effective against all respiratory pathogens: Many respiratory infections are viral, and ampicillin won’t be helpful in these cases. Consult your doctor: Self-medicating with antibiotics is dangerous and contributes to antibiotic resistance. Always seek professional medical advice.
Ampicillin’s role in respiratory tract infections is part of a broader strategy involving appropriate diagnosis, tailored treatment, and responsible antibiotic stewardship.


