Ampicillin is normally used to treat cholera and typhoid fever, lowering the immunological response that the body has to mount. Pharmacology
Mechanism of action
Ampicillin is in the penicillin group of beta-lactam antibiotics and is part of the aminopenicillin family. It is roughly equivalent to amoxicillin in terms of activity. Ampicillin is able to penetrate gram-positive and some gram-negative bacteria. It differs from penicillin G, or benzylpenicillin, only by the presence of an amino group. This amino group, present on both ampicillin and amoxicillin, helps these antibiotics pass through the pores of the outer membrane of gram-negative bacteria, such as E. coli, Proteus mirabilis, Salmonella enterica, and Shigella.Ampicillin acts as an irreversible inhibitor of the enzyme transpeptidase, which is needed by bacteria to make the cell wall. It inhibits the third and final stage of bacterial cell wall synthesis in binary fission, which ultimately leads to cell lysis; therefore, ampicillin is usually bacteriolytic. Pharmacokinetics
Ampicillin is well-absorbed from the GI tract (though food reduces its absorption), and reaches peak concentrations in one to two hours. The bioavailability is around 62% for parenteral routes. Unlike other penicillins, which usually bind 60–90% to plasma proteins, ampicillin binds to only 15–20%.Ampicillin is distributed through most tissues, though it is concentrated in the liver and kidneys. It can also be found in the cerebrospinal fluid when the meninges become inflamed (such as, for example, meningitis). Some ampicillin is metabolized by hydrolyzing the beta-lactam ring to penicilloic acid, though most of it is excreted unchanged.
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. 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 Organizations List of Essential Medicines. The World Health Organization classifies ampicillin as critically important for human medicine. It is available as a generic medication. Medical uses
Diseases
Bacterial meningitis; an aminoglycoside can be added to increase efficacy against gram-negative meningitis bacteria
Endocarditis by enterococcal strains (off-label use); often given with an aminoglycoside
Gastrointestinal infections caused by contaminated water or food (for example, by Salmonella)
Genito-urinary tract infections
Healthcare-associated infections that are related to infections from using urinary catheters and that are unresponsive to other medications
Otitis media (middle ear infection)
Prophylaxis (i.e. to prevent infection) in those who previously had rheumatic heart disease or are undergoing dental procedures, vaginal hysterectomies, or C-sections. It is also used in pregnant woman who are carriers of group B streptococci to prevent early-onset neonatal infections.