Ampicin-Vet

Ampicillin is indicated in patients with infections caused by susceptible bacteria, such as skin and soft tissue infections, UTIs, and pneumonia. Gram-positive bacteria (except beta-lactamase– producing strains of Staphylococcus spp.) are usually susceptible. However, infections caused by most gram-negative bacteria of the Enterobacteriaceae are clinically resistant. Fastidious gram-negative bacteria (e.g., Pasteurella) are usually clinically susceptible.

Use cautiously in animals allergic to penicillin-like drugs.

Beta-lactam antibiotic. Ampicillin inhibits bacterial cell wall synthesis. Ampicillin has a narrow spectrum of activity that is similar to that of amoxicillin. Ampicillin spectrum of activity includes streptococci, non–beta-lactamase– producing staphylococci, and other gram-positive cocci and bacilli. Many staphylococci are resistant because of beta-lactamase production. Most enteric gram-negative bacilli of the Enterobacteriaceae are clinically resistant. Susceptible gram-negative bacteria include some species of Proteus spp., Pasteurella multocida, and Histophilus spp.

BACTERIOSTATIC ANTIMICROBIALS (e.g., chloramphenicol, erythromycin and other macrolides, tetracyclines, sulfonamides, etc.): Because there is evidence of in vitro antagonism between beta-lactam antibiotics and bacteriostatic antibiotics, use together has not been generally recommended in the past, but actual clinical importance is not clear and currently in doubt.
METHOTREXATE: Ampicillin may decrease the renal excretion of MTX causing increased levels and potential toxic effects
PROBENECID: Competitively blocks the tubular secretion of most penicillins thereby increasing serum levels and serum half-lives

Adverse effects of penicillin drugs are most commonly caused by drug allergy. This can range from acute anaphylaxis when administered IV to other signs of allergic reaction when other routes are used. When used for prophylaxis during surgery, ampicillin can be administered IV to anesthetized patients without affecting cardiovascular parameters. Diarrhea is possible when administered orally, especially with high doses

Acute oral penicillin overdoses are unlikely to cause significant problems other than GI distress, but other effects are possible (see Adverse Effects). In humans, very high dosages of parenteral penicillins, particularly in patients with renal disease, have induced CNS effects.

Penicillins have been shown to cross the placenta; safe use during pregnancy has not been firmly established, but neither have there been any documented teratogenic problems associated with these drugs. However, use only when the potential benefits outweigh the risks.

Rapid IV bolus injection can produce CNS excitement and convulsive seizures.