|Trade names||Principen, others|
|By mouth, intravenous|
|Protein binding||15 to 25%|
|Metabolism||12 to 50%|
|Biological half-life||approx 1 hour|
|Excretion||75 to 85% renal|
|Chemical and physical data|
|Molar mass||349.41 g/mol|
|3D model (Jmol)|
Ampicillin is an antibiotic used to prevent and treat a number of bacterial infections, such as respiratory tract infections, urinary tract infections, meningitis, salmonellosis, and endocarditis. It may also be used to prevent group B streptococcal infection in newborns. It is used by mouth, by injection into a muscle, or intravenously. Like all antibiotics, it is not useful for the treatment of viral infections.
Common side effects include rash, nausea, and diarrhea. It should not be used in people who are allergic to penicillin. Serious side effects may include Clostridium difficile colitis or anaphylaxis. While usable in those with kidney problems, the dose may need to be decreased. Its use during pregnancy and breastfeeding appears to be generally safe.
Ampicillin was discovered in 1958 and came into commercial use in 1961. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Its wholesale cost in the developing world is between US$0.13 and 1.20 for a vial of the intravenous solution as of 2014. In the United States, it is available as a generic medication and 10 days of treatment cost about $13.