What is ampicillin used for?

Indications and Usage, quoted from the label by WG Critical Care, LLC (ANDA090354). Cross-references to other label sections are left out.

Ampicillin for Injection, USP is indicated in the treatment of infections caused by susceptible strains of the designated organisms in the following conditions:

Respiratory Tract Infections caused by S. pneumoniae, Staphylococcus aureus (penicillinase and non-penicillinase producing), H. influenzae and Group A beta-hemolytic Streptococci.

Bacterial Meningitis caused by E. coli, Group B Streptococci, and other Gram-negative bacteria (Listeria monocytogenes, N. meningitidis). The addition of an aminoglycoside with ampicillin may increase its effectiveness against Gram-negative bacteria.

Septicemia and Endocarditis caused by susceptible Gram-positive organisms including Streptococcus spp., penicillin-G-susceptible staphylococci and enterococci. Gram-negative sepsis caused by E. coli, Proteus mirabilis and Salmonella spp. responds to ampicillin. Endocarditis due to enterococcal strains usually respond to intravenous therapy. The addition of an aminoglycoside may enhance the effectiveness of ampicillin when treating streptococcal endocarditis.

Urinary Tract Infections caused by sensitive strains of E. coli and Proteus mirabilis.

Gastrointestinal Infections caused by Salmonella typhi (typhoid fever), other Salmonella spp. and Shigella spp. (dysentery) usually respond to oral or intravenous therapy.

Bacteriology studies to determine the causative organisms and their susceptibility to ampicillin should be performed. Therapy may be instituted prior to obtaining results of susceptibility testing.

It is advisable to reserve the parenteral form of this drug for moderately severe and severe infections and for patients who are unable to take the oral forms. A change to oral ampicillin may be made as soon as appropriate. Indicated surgical procedures should be performed.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Ampicillin for Injection, USP and other antibacterial drugs, Ampicillin for Injection, USP should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

Source: DailyMed label, set id 38ec7b7a-9caf-45f2-88a1-0f78f089a1e4, version 27, effective June 22, 2026. NDC 44567-100, one of 66 listings for this product.

Indications and Usage, quoted from the label by Aurobindo Pharma Limited (ANDA216554). Cross-references to other label sections are left out.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of ampicillin capsules and other antibacterial drugs, ampicillin capsules should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria. When culture and susceptibility information are available, they should be considered in selecting of modifying antimicrobial therapy, in the absence of such data, local epidemiology and susceptibility patterns contribute to the empiric selection of therapy.

Ampicillin capsules are indicated in the treatment of infections caused by susceptible strains of the designated organisms listed below:

Infections of the genitourinary tract including gonorrhea: E. coli, P. mirabilis, enterococci, Shigella, S. typhosa and other Salmonella, and nonpenicillinase producing N. gonorrhoeae.

Infections of the respiratory tract: Nonpenicillinase- producing H. influenzae and staphylococci, and streptococci including streptococcus pneumoniae.

Infections of the gastrointestinal tract: Shigella, S. typhosa and other Salmonella, E. coli, P. mirabilis, and enterococci.

Meningitis: N. Meningitides.

Bacteriology studies to determine the causative organisms and their susceptibility to ampicillin capsules should be performed. Therapy may be instituted prior to the results of susceptibility testing.

Source: DailyMed label, set id 7f8b1ab1-73c6-4cdf-a838-7a4554c62586, version 4, effective August 14, 2025. NDC 59651-550, one of 4 listings for this product.

Indications and Usage, quoted from the label by Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc. (ANDA090354). Cross-references to other label sections are left out.

Ampicillin for Injection, USP is indicated in the treatment of infections caused by susceptible strains of the designated organisms in the following conditions:

Respiratory Tract Infections caused by Streptococcus pneumoniae, Staphylococcus aureus (penicillinase and nonpenicillinase-producing), H. influenzae, and Group A beta-hemolytic Streptococci.

Bacterial Meningitis caused by E. coli, Group B Streptococci, and other Gram-negative bacteria (Listeria monocytogenes, N. meningitidis). The addition of an aminoglycoside with ampicillin may increase its effectiveness against Gram-negative bacteria.

Septicemia and Endocarditis caused by susceptible Gram-positive organisms including Streptococcus spp., penicillin G-susceptible staphylococci, and enterococci. Gram-negative sepsis caused by E. coli, Proteus mirabilis and Salmonella spp. responds to ampicillin. Endocarditis due to enterococcal strains usually respond to intravenous therapy. The addition of an aminoglycoside may enhance the effectiveness of ampicillin when treating streptococcal endocarditis.

Urinary Tract Infections caused by sensitive strains of E. coli and Proteus mirabilis.

Gastrointestinal Infections caused by Salmonella typhi (typhoid fever), other Salmonella spp., and Shigella spp. (dysentery) usually respond to oral or intravenous therapy.

Bacteriology studies to determine the causative organisms and their susceptibility to ampicillin should be performed. Therapy may be instituted prior to obtaining results of susceptibility testing.

It is advisable to reserve the parenteral form of this drug for moderately severe and severe infections and for patients who are unable to take the oral forms. A change to oral ampicillin may be made as soon as appropriate.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Ampicillin for Injection, USP and other antibacterial drugs, Ampicillin for Injection, USP should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

Indicated surgical procedures should be performed.

Source: DailyMed label, set id 302e6df7-37c5-4625-8a61-3e2f302addf2, version 2, effective November 7, 2025. NDC 23155-914, one of 4 listings for this product.