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

• Sterile, non-aqueous suspension.
• White tablets.
• Clear yellow aqueous solution.
• Red and gray capsules.

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 E. coli and Staphylococcus aureus.
• The difficult gram negative organisms (eg Pseudomonas spp and Klebsiella spp) are usually resistant.
• Most obligate anaerobes are susceptible.
• Ampicillin is excreted well in bile and urine.

Administration

Precautions

Interactions

with other drugs

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

• 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 B (1999) 3rd edn. BSAVA, UK.