Introduction

Name

• Ampicillin.

Class of drug

• Aminopenicillin.

Description

Chemical name

• [2S-[2-alpha,5-alpha,6-beta(S*)]]-6-(aminophenylacetyl)amino]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid.

Molecular formula

• C16H19N3O4S.

Physical properties

• Ampicillin sodium - water soluble for IV injection.
• Ampicillin trihydrate - suspension for SQ or IM injection.

Storage requirements

• <25°C.
• Store tablets in a dry environment.
• Do not store in freezer.
• Can be stored in fridge (between 2-8°C).

Uses

Indications

• Ampicillin is an acid-stable, beta-lactamase-susceptible aminopenicillin active against many Gram-positive and negative organisms, but not against those that produce penicillinases, eg some E. coli  Escherichia coli  and Staphylococcus aureus  Staphylococcus aureus  .
• The difficult Gram negative organisms, eg Pseudomonas spp.  Pseudomonas spp  and Klebsiella spp.  Klebsiella pneumoniae   are usually resistant.
• Most obligate anaerobes are susceptible.
• Ampicillin is excreted well in bile and urine.

Administration

Pharmacokinetics

Precautions

Interactions

with other drugs

• Avoid the concurrent use of ampicillin with bacteriostatic antibiotics (eg erythromycin   Erythromycin  , chloramphenicol   Chloramphenicol  ).
• Probenecid will decrease the renal tubular secretion of penicillin antibiotics and thus prolong their blood levels.

Aminoglycosides

• Do not mix in the same syringe as aminoglycosides.

Adverse Reactions

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.

Other sources of information

• Based on Small Animal Formulary. Tennant, Bryn (1999) 3rd edn. BSAVA, UK.