Ampicillin is an

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...

used to prevent and treat a number of

bacterial infection Pathogenic bacteria are bacteria that can cause disease. This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and are often beneficial but others can cause infectious diseases. The number of ...

s, such as

respiratory tract infection Respiratory tract infections (RTIs) are infectious diseases involving the respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection (URI or URTI) or a lower respiratory tract infection (LRI ...

urinary tract infections A urinary tract infection (UTI) is an infection that affects part of the urinary tract. When it affects the lower urinary tract it is known as a bladder infection (cystitis) and when it affects the upper urinary tract it is known as a kidney ...

meningitis Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, headache, and neck stiffness. Other symptoms include confusion or ...

salmonellosis Salmonellosis, more commonly known as food poisoning is a symptomatic infection caused by bacteria of the ''Salmonella'' type. It is also a food-borne disease and are defined as diseases, usually either infectious or toxic in nature, caused by a ...

, and

endocarditis Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves. Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or the ...

. It may also be used to prevent

group B streptococcal infection Group B streptococcal infection, also known as Group B streptococcal disease or just Group B strep, is the infection caused by the bacterium ''Streptococcus agalactiae'' (''S. agalactiae'') (also known as group B streptococcus or GBS). GBS infecti ...

in newborns. It is used by mouth, by

injection into a muscle Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles ha ...

, or intravenously. Common side effects include rash, nausea, and diarrhea. It should not be used in people who are

allergic to penicillin Penicillins (P, PCN or PEN) are a group of β-lactam antibiotics originally obtained from ''Penicillium'' moulds, principally '' P. chrysogenum'' and '' P. rubens''. Most penicillins in clinical use are synthesised by P. chrysogenum using ...

. Serious side effects may include ''Clostridium difficile'' colitis or

anaphylaxis Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the follow ...

. While usable in those with

kidney problem Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as eit ...

s, the dose may need to be decreased. Its use during

pregnancy Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but ca ...

and

breastfeeding Breastfeeding, or nursing, is the process by which human breast milk is fed to a child. Breast milk may be from the breast, or may be expressed by hand or pumped and fed to the infant. The World Health Organization (WHO) recommends that br ...

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 WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health s ...

. The World Health Organization classifies ampicillin as critically important for human medicine. It is available as a

generic medication A generic drug is a pharmaceutical drug that contains the same chemical substance as a drug that was originally protected by chemical patents. Generic drugs are allowed for sale after the patents on the original drugs expire. Because the active ch ...

Medical uses

Diseases

Bacterial meningitis Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, headache, and neck stiffness. Other symptoms include confusion or ...

; an aminoglycoside can be added to increase efficacy against gram-negative meningitis bacteria *

Endocarditis Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves. Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or the ...

by enterococcal strains (off-label use); often given with an aminoglycoside *

Gastrointestinal The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...

infections caused by contaminated water or food (for example, by '' Salmonella'') *

Genito-urinary tract The genitourinary system, or urogenital system, are the organs of the reproductive system and the urinary system. These are grouped together because of their proximity to each other, their common embryological origin and the use of common pathwa ...

infections *

Healthcare-associated infections A hospital-acquired infection, also known as a nosocomial infection (from the Greek , meaning "hospital"), is an infection that is acquired in a hospital or other health care facility. To emphasize both hospital and nonhospital settings, it is so ...

that are related to infections from using urinary catheters and that are unresponsive to other medications *

Otitis media Otitis media is a group of inflammatory diseases of the middle ear. One of the two main types is acute otitis media (AOM), an infection of rapid onset that usually presents with ear pain. In young children this may result in pulling at the ear, ...

(middle ear infection) *Prophylaxis (i.e. to prevent infection) in those who previously had

rheumatic heart disease Rheumatic fever (RF) is an inflammatory disease that can involve the heart, joints, skin, and brain. The disease typically develops two to four weeks after a streptococcal throat infection. Signs and symptoms include fever, multiple painful jo ...

or are undergoing dental procedures, vaginal

hysterectomies Hysterectomy is the surgical removal of the uterus. It may also involve removal of the cervix, ovaries (oophorectomy), Fallopian tubes ( salpingectomy), and other surrounding structures. Usually performed by a gynecologist, a hysterectomy may be ...

, or C-sections. It is also used in pregnant woman who are carriers of

group B streptococci ''Streptococcus agalactiae'' (also known as group B streptococcus or GBS) is a gram-positive bacteria, gram-positive coccus (round bacteria, bacterium) with a tendency to form chains (as reflected by the genus name ''Streptococcus''). It is a be ...

to prevent early-onset neonatal infections. *

Respiratory infections Respiratory tract infections (RTIs) are infectious diseases involving the respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection (URI or URTI) or a lower respiratory tract infection (LRI ...

, including

bronchitis Bronchitis is inflammation of the bronchi (large and medium-sized airways) in the lungs that causes coughing. Bronchitis usually begins as an infection in the nose, ears, throat, or sinuses. The infection then makes its way down to the bronchi. ...

pharyngitis Pharyngitis is inflammation of the back of the throat, known as the pharynx. It typically results in a sore throat and fever. Other symptoms may include a Rhinorrhea, runny nose, cough, headache, difficulty swallowing, swollen lymph nodes, and a ...

Sinusitis Sinusitis, also known as rhinosinusitis, is inflammation of the mucous membranes that line the sinuses resulting in symptoms that may include thick nasal mucus, a plugged nose, and facial pain. Other signs and symptoms may include fever, head ...

Sepsis Sepsis, formerly known as septicemia (septicaemia in British English) or blood poisoning, is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage is follo ...

Whooping cough Whooping cough, also known as pertussis or the 100-day cough, is a highly contagious bacterial disease. Initial symptoms are usually similar to those of the common cold with a runny nose, fever, and mild cough, but these are followed by two or t ...

, to prevent and treat

secondary infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dis ...

s Ampicillin used to also be used to treat

gonorrhea Gonorrhea, colloquially known as the clap, is a sexually transmitted infection (STI) caused by the bacterium '' Neisseria gonorrhoeae''. Infection may involve the genitals, mouth, or rectum. Infected men may experience pain or burning with ...

, but there are now too many strains resistant to penicillins.

Bacteria

Ampicillin is used to treat infections by many

gram-positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bacte ...

and

gram-negative bacteria Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...

. It was the first "broad spectrum" penicillin with activity against gram-positive bacteria, including ''

Streptococcus pneumoniae ''Streptococcus pneumoniae'', or pneumococcus, is a Gram-positive, spherical bacteria, alpha-hemolytic (under aerobic conditions) or beta-hemolytic (under anaerobic conditions), aerotolerant anaerobic member of the genus Streptococcus. They ar ...

'', ''

Streptococcus pyogenes ''Streptococcus pyogenes'' is a species of Gram-positive, aerotolerant bacteria in the genus ''Streptococcus''. These bacteria are extracellular, and made up of non-motile and non-sporing cocci (round cells) that tend to link in chains. They are ...

'', some isolates of ''

Staphylococcus aureus ''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive ...

'' (but not penicillin-resistant or methicillin-resistant strains), '' Trueperella'', and some ''

Enterococcus ''Enterococcus'' is a large genus of lactic acid bacteria of the phylum Bacillota. Enterococci are gram-positive cocci that often occur in pairs (diplococci) or short chains, and are difficult to distinguish from streptococci on physical char ...

''. It is one of the few antibiotics that works against multidrug resistant ''

Enterococcus faecalis ''Enterococcus faecalis'' – formerly classified as part of the group D ''Streptococcus'' system – is a Gram-positive, commensal bacterium inhabiting the gastrointestinal tracts of humans. Like other species in the genus ''Enterococcus'', ''E ...

'' and '' E. faecium''. Activity against gram-negative bacteria includes ''

Neisseria meningitidis ''Neisseria meningitidis'', often referred to as meningococcus, is a Gram-negative bacterium that can cause meningitis and other forms of meningococcal disease such as meningococcemia, a life-threatening sepsis. The bacterium is referred to as a ...

'', some ''

Haemophilus influenzae ''Haemophilus influenzae'' (formerly called Pfeiffer's bacillus or ''Bacillus influenzae'') is a Gram-negative, non-motile, coccobacillary, facultatively anaerobic, capnophilic pathogenic bacterium of the family Pasteurellaceae. The bacteria ...

'', and some of the Enterobacteriaceae (though most Enterobacteriaceae and ''

Pseudomonas ''Pseudomonas'' is a genus of Gram-negative, Gammaproteobacteria, belonging to the family Pseudomonadaceae and containing 191 described species. The members of the genus demonstrate a great deal of metabolic diversity and consequently are able ...

'' are resistant). Its spectrum of activity is enhanced by co-administration of

sulbactam Sulbactam is a β-lactamase inhibitor. This drug is given in combination with β-lactam antibiotics to inhibit β-lactamase, an enzyme produced by bacteria that destroys the antibiotics. It was patented in 1977 and approved for medical use in ...

, a drug that inhibits

beta lactamase Beta-lactamases, (β-lactamases) are enzymes () produced by bacteria that provide multi-resistance to beta-lactam antibiotics such as penicillins, cephalosporins, cephamycins, monobactams and carbapenems (ertapenem), although carbapenem ...

, an enzyme produced by bacteria to inactivate ampicillin and related antibiotics. It is sometimes used in combination with other antibiotics that have different mechanisms of action, like

vancomycin Vancomycin is a glycopeptide antibiotic medication used to treat a number of bacterial infections. It is recommended intravenously as a treatment for complicated skin infections, bloodstream infections, endocarditis, bone and joint infections, ...

linezolid Linezolid is an antibiotic used for the treatment of infections caused by Gram-positive bacteria that are resistant to other antibiotics. Linezolid is active against most Gram-positive bacteria that cause disease, including streptococci, van ...

daptomycin Daptomycin, sold under the brand name Cubicin among others, is a lipopeptide antibiotic used in the treatment of systemic and life-threatening infections caused by Gram-positive organisms. Daptomycin was removed from the World Health Organiza ...

, and

tigecycline Tigecycline, sold under the brand name Tygacil, is an tetracycline antibiotic medication for a number of bacterial infections. It is a glycylcycline administered intravenously. It was developed in response to the growing rate of antibiotic resist ...

Available forms

Ampicillin can be administered by mouth, an

intramuscular injection Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles have ...

(shot) or by

intravenous infusion Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrie ...

. The oral form, available as capsules or oral suspensions, is not given as an initial treatment for severe infections, but rather as a follow-up to an IM or IV injection. For IV and IM injections, ampicillin is kept as a powder that must be reconstituted. IV injections must be given slowly, as rapid IV injections can lead to convulsive

seizures An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with l ...

Specific populations

Ampicillin is one of the most used drugs in pregnancy, and has been found to be generally harmless both by the

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

in the U.S. (which classified it as category B) and the

Therapeutic Goods Administration The Therapeutic Goods Administration (TGA) is the medicine and therapeutic regulatory agency of the Australian Government. As part of the Department of Health and Aged Care, the TGA regulates the quality, supply and advertising of medicines, pa ...

in Australia (which classified it as category A). It is the drug of choice for treating ''

Listeria monocytogenes ''Listeria monocytogenes'' is the species of pathogenic bacteria that causes the infection listeriosis. It is a facultative anaerobic bacterium, capable of surviving in the presence or absence of oxygen. It can grow and reproduce inside the host' ...

'' in pregnant women, either alone or combined with an aminoglycoside. Pregnancy increases the clearance of ampicillin by up to 50%, and a higher dose is thus needed to reach therapeutic levels. Ampicillin crosses the

placenta The placenta is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas and waste exchange between the physically separate mater ...

and remains in the

amniotic fluid The amniotic fluid is the protective liquid contained by the amniotic sac of a gravid amniote. This fluid serves as a cushion for the growing fetus, but also serves to facilitate the exchange of nutrients, water, and biochemical products betwee ...

at 50–100% of the concentration in maternal plasma; this can lead to high concentrations of ampicillin in the newborn. While lactating mothers secrete some ampicillin into their breast milk, the amount is minimal. In newborns, ampicillin has a longer half-life and lower plasma protein binding. The clearance by the kidneys is lower, as kidney function has not fully developed.

Contraindications

Ampicillin is contraindicated in those with a hypersensitivity to penicillins, as they can cause fatal

anaphylactic Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the follo ...

reactions. Hypersensitivity reactions can include frequent skin

rash A rash is a change of the human skin which affects its color, appearance, or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, c ...

es and hives, exfoliative dermatitis,

erythema multiforme Erythema multiforme (EM) is a skin condition that appears with red patches evolving into target lesions, typically on both hands. It is a type of erythema possibly mediated by deposition of immune complexes (mostly IgM-bound complexes) in th ...

, and a temporary decrease in both

red Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–740 nanometres. It is a primary color in the RGB color model and a secondar ...

and

white blood cells White blood cells, also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from mult ...

. Ampicillin is not recommended in people with concurrent mononucleosis, as over 40% of patients develop a skin rash.

Side effects

Ampicillin is comparatively less toxic than other antibiotics, and side effects are more likely in those who are sensitive to penicillins and those with a history of

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, cou ...

allergies Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermat ...

. In very rare cases, it causes severe side effects such as

angioedema Angioedema is an area of swelling ( edema) of the lower layer of skin and tissue just under the skin or mucous membranes. The swelling may occur in the face, tongue, larynx, abdomen, or arms and legs. Often it is associated with hives, which ...

, anaphylaxis, and '' C. difficile'' infection (that can range from mild

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin wi ...

to serious

pseudomembranous colitis Colitis is swelling or inflammation of the large intestine ( colon). Colitis may be acute and self-limited or long-term. It broadly fits into the category of digestive diseases. In a medical context, the label ''colitis'' (without qualificatio ...

). Some develop black "furry" tongue. Serious adverse effects also include

seizure An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with l ...

s and

serum sickness Serum sickness in humans is a reaction to proteins in antiserum derived from a non-human animal source, occurring 5–10 days after exposure. Symptoms often include a rash, joint pain, fever, and lymphadenopathy. It is a type of hypersensitivity ...

. The most common side effects, experienced by about 10% of users are diarrhea and rash. Less common side effects can be

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteri ...

itching Itch (also known as pruritus) is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to be classified as any one type of sensory experience. Itch has many similarities to pain, and while both are unpleasan ...

, and blood

dyscrasia In medicine, both ancient and modern, a dyscrasia is any of various disorders. The word has ancient Greek roots meaning "bad mixture". The concept of dyscrasia was developed by the Greek physician Galen (129–216 AD), who elaborated a model of h ...

s. The gastrointestinal effects, such as hairy tongue, nausea, vomiting, diarrhea, and colitis, are more common with the oral form of penicillin. Other conditions may develop up several weeks after treatment.

Overdose

Ampicillin overdose can cause behavioral changes,

confusion In medicine, confusion is the quality or state of being bewildered or unclear. The term "acute mental confusion"

, blackouts, and convulsions, as well as neuromuscular hypersensitivity,

electrolyte imbalance Electrolyte imbalance, or water-electrolyte imbalance, is an abnormality in the concentration of electrolytes in the body. Electrolytes play a vital role in maintaining homeostasis in the body. They help to regulate heart and neurological function, ...

, and

kidney failure Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as eit ...

Interactions

Ampicillin reacts with

probenecid Probenecid, also sold under the brand name Probalan, is a medication that increases uric acid excretion in the urine. It is primarily used in treating gout and hyperuricemia. Probenecid was developed as an alternative to caronamide to competitive ...

and methotrexate to decrease

renal excretion In pharmacology, clearance is a pharmacokinetics, pharmacokinetic measurement of the volume of blood plasma, plasma from which a substance is completely removed per unit time. Usually, clearance is measured in L/h or mL/min. The quantity reflects t ...

. Large doses of ampicillin can increase the risk of bleeding with concurrent use of

warfarin Warfarin, sold under the brand name Coumadin among others, is a medication that is used as an anticoagulant (blood thinner). It is commonly used to prevent blood clots such as deep vein thrombosis and pulmonary embolism, and to prevent st ...

and other oral anticoagulants, possibly by inhibiting platelet aggregation. Ampicillin has been said to make

oral contraceptives Oral contraceptives, abbreviated OCPs, also known as birth control pills, are medications taken by mouth for the purpose of birth control. Female Two types of female oral contraceptive pill, taken once per day, are widely available: * The combin ...

less effective, but this has been disputed. It can be made less effective by other antibiotic, such as chloramphenicol,

erythromycin Erythromycin is an antibiotic used for the treatment of a number of bacterial infections. This includes respiratory tract infections, skin infections, chlamydia infections, pelvic inflammatory disease, and syphilis. It may also be used duri ...

cephalosporins The cephalosporins (sg. ) are a class of β-lactam antibiotics originally derived from the fungus ''Acremonium'', which was previously known as ''Cephalosporium''. Together with cephamycins, they constitute a subgroup of β-lactam antibiotics ...

, and

tetracyclines Tetracyclines are a group of broad-spectrum antibiotic compounds that have a common basic structure and are either isolated directly from several species of ''Streptomyces'' bacteria or produced semi-synthetically from those isolated compounds. T ...

. For example, tetracyclines inhibit protein synthesis in bacteria, reducing the target against which ampicillin acts. If given at the same time as aminoglycosides, it can bind to it and inactivate it. When administered separately, aminoglycosides and ampicillin can potentiate each other instead. Ampicillin causes skin rashes more often when given with

allopurinol Allopurinol is a medication used to decrease high blood uric acid levels. It is specifically used to prevent gout, prevent specific types of kidney stones and for the high uric acid levels that can occur with chemotherapy. It is taken by mouth ...

. Both the live cholera vaccine and live typhoid vaccine can be made ineffective if given with ampicillin. 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 Penicillins (P, PCN or PEN) are a group of β-lactam antibiotics originally obtained from ''Penicillium'' moulds, principally '' P. chrysogenum'' and '' P. rubens''. Most penicillins in clinical use are synthesised by P. chrysogenum using ...

group of

beta-lactam antibiotic β-lactam antibiotics (beta-lactam antibiotics) are antibiotics that contain a beta-lactam ring in their chemical structure. This includes penicillin derivatives (penams), cephalosporins and cephamycins (cephems), monobactams, carbapenems and ...

s and is part of the aminopenicillin family. It is roughly equivalent to

amoxicillin Amoxicillin is an antibiotic medication used to treat a number of bacterial infections. These include middle ear infection, strep throat, pneumonia, skin infections, and urinary tract infections among others. It is taken by mouth, or less c ...

in terms of activity. Ampicillin is able to penetrate gram-positive and some gram-negative bacteria. It differs from

penicillin G Benzylpenicillin, also known as penicillin G (PenG) or BENPEN, and in military slang "Peanut Butter Shot" is an antibiotic used to treat a number of bacterial infections. This includes pneumonia, strep throat, syphilis, necrotizing enteroco ...

, or benzylpenicillin, only by the presence of an

amino In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent ...

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 ''Proteus mirabilis'' is a Gram-negative, facultatively anaerobic, rod-shaped bacterium. It shows swarming motility and urease activity. ''P. mirabilis'' causes 90% of all ''Proteus'' infections in humans. It is widely distributed in soil and ...

'', ''

Salmonella enterica ''Salmonella enterica'' (formerly ''Salmonella choleraesuis'') is a rod-headed, flagellate, facultative anaerobic, Gram-negative bacterium and a species of the genus ''Salmonella''. A number of its serovars are serious human pathogens. Epidemi ...

'', and ''

Shigella ''Shigella'' is a genus of bacteria that is Gram-negative, facultative anaerobic, non-spore-forming, nonmotile, rod-shaped, and genetically closely related to '' E. coli''. The genus is named after Kiyoshi Shiga, who first discovered it in 1 ...

''. 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 Binary may refer to: Science and technology Mathematics * Binary number, a representation of numbers using only two digits (0 and 1) * Binary function, a function that takes two arguments * Binary operation, a mathematical operation that ta ...

, which ultimately leads to cell

lysis Lysis ( ) is the breaking down of the membrane of a cell, often by viral, enzymic, or osmotic (that is, "lytic" ) mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a ''lysate''. In molecular bio ...

; therefore, ampicillin is usually bacteriolytic.

Pharmacokinetics

Ampicillin is well-absorbed from the

GI tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans ...

(though food reduces its absorption), and reaches peak concentrations in one to two hours. The

bioavailability In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. Ho ...

is around 62% for parenteral routes. Unlike other penicillins, which usually bind 60–90% to

plasma proteins Blood-proteins, also termed plasma proteins, are proteins present in blood plasma. They serve many different functions, including transport of lipids, hormones, vitamins and minerals in activity and functioning of the immune system. Other blood p ...

, 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 Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the bra ...

when the meninges become inflamed (such as, for example, meningitis). Some ampicillin is metabolized by hydrolyzing the beta-lactam ring to

penicilloic acid Penicilloic acid is any of several acids which are obtained from the penicillins by the hydrolytic opening of the lactam ring (as by the action of a beta-lactamase). Hypersensitivity is the most important adverse effect of the penicillins. The majo ...

, though most of it is excreted unchanged. In the kidneys, it is filtered out mostly by

tubular secretion Renal physiology (Latin ''rēnēs'', "kidneys") is the study of the physiology of the kidney. This encompasses all functions of the kidney, including maintenance of acid-base balance; regulation of fluid balance; regulation of sodium, potassium, ...

; some also undergoes

glomerular filtration Renal functions include maintaining an acid–base balance; regulating fluid balance; regulating sodium, potassium, and other electrolytes; clearing toxins; absorption of glucose, amino acids, and other small molecules; regulation of blood pre ...

, and the rest is excreted in the feces and

bile Bile (from Latin ''bilis''), or gall, is a dark-green-to-yellowish-brown fluid produced by the liver of most vertebrates that aids the digestion of lipids in the small intestine. In humans, bile is produced continuously by the liver (liver bile ...

Hetacillin Hetacillin is a beta-lactam antibiotic that is part of the aminopenicillin family. It is a prodrug and has no antibacterial activity itself, but quickly splits off acetone in the human body to form ampicillin, which is active against a variety o ...

and

pivampicillin Pivampicillin is a pivaloyloxymethyl ester of ampicillin. It is a prodrug, which is thought to enhance the oral bioavailability of ampicillin because of its greater lipophilicity compared to that of ampicillin. Adverse effects Prodrugs that rele ...

are ampicillin

esters In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are ...

that have been developed to increase bioavailability.

History

Ampicillin has been used extensively to treat bacterial infections since 1961. Until the introduction of ampicillin by the British company Beecham, penicillin therapies had only been effective against gram-positive organisms such as

staphylococci ''Staphylococcus'' is a genus of Gram-positive bacteria in the family Staphylococcaceae from the order Bacillales. Under the microscope, they appear spherical ( cocci), and form in grape-like clusters. ''Staphylococcus'' species are facultati ...

and streptococci. Ampicillin (originally branded as "Penbritin") also demonstrated activity against gram-negative organisms such as ''H. influenzae'',

coliform Coliform bacteria are defined as either motile or non-motile Gram-negative non- spore forming Bacilli that possess β-galactosidase to produce acids and gases under their optimal growth temperature of 35-37°C. They can be aerobes or facultativ ...

s, and ''

Proteus In Greek mythology, Proteus (; Ancient Greek: Πρωτεύς, ''Prōteus'') is an early prophetic sea-god or god of rivers and oceanic bodies of water, one of several deities whom Homer calls the "Old Man of the Sea" ''(hálios gérôn)''. ...

'' spp.

Cost

Ampicillin is relatively inexpensive. In the United States, it is available as a

Veterinary use

In veterinary medicine, ampicillin is used in cats, dogs, and farm animals to treat: *

Anal gland Anal may refer to: Related to the anus *Related to the anus of animals: ** Anal fin, in fish anatomy ** Anal vein, in insect anatomy ** Anal scale, in reptile anatomy *Related to the human anus: ** Anal sex, a type of sexual activity involvi ...

infections * Cutaneous infections, such as

abscesses An abscess is a collection of pus that has built up within the tissue of the body. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pressed. The area of redness often extends ...

cellulitis Cellulitis is usually a bacterial infection involving the inner layers of the skin. It specifically affects the dermis and subcutaneous fat. Signs and symptoms include an area of redness which increases in size over a few days. The borders of ...

, and pustular

dermatitis Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can ...

* ''E. coli'' and ''Salmonella'' infections in

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult mal ...

sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus ''Ovis'', in everyday usage it almost always refers to domesticated s ...

, and

goats The goat or domestic goat (''Capra hircus'') is a domesticated species of Caprinae, goat-antelope typically kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a membe ...

(oral form). Ampicillin use for this purpose had declined as bacterial resistance has increased. *

Mastitis Mastitis is inflammation of the breast or udder, usually associated with breastfeeding. Symptoms typically include local pain and redness. There is often an associated fever and general soreness. Onset is typically fairly rapid and usually occurs ...

in sows * Mixed aerobic–anaerobic infections, such as from cat bites * Multidrug-resistant ''Enterococcus faecalis'' and ''E. faecium'' * Prophylactic use in

poultry Poultry () are domesticated birds kept by humans for their eggs, their meat or their feathers. These birds are most typically members of the superorder Galloanserae (fowl), especially the order Galliformes (which includes chickens, quails, a ...

against ''Salmonella'' and sepsis from ''E. coli'' or ''Staphylococcus aureus'' *

Respiratory tract infections Respiratory tract infections (RTIs) are infectious diseases involving the respiratory tract. An infection of this type usually is further classified as an upper respiratory tract infection (URI or URTI) or a lower respiratory tract infection (LRI ...

, including

tonsilitis Tonsillitis is inflammation of the tonsils in the upper part of the throat. It can be acute or chronic. Acute tonsillitis typically has a rapid onset. Symptoms may include sore throat, fever, enlargement of the tonsils, trouble swallowing, and en ...

bovine respiratory disease Bovine respiratory disease (BRD) is the most common and costly disease affecting beef cattle in the world. It is a complex, bacterial or viral infection that causes pneumonia in calves which can be fatal. The infection is usually a sum of three c ...

, shipping fever,

bronchopneumonia Bronchopneumonia is a subtype of pneumonia. It is the acute inflammation of the bronchi, accompanied by inflamed patches in the nearby lobules of the lungs. citing: Webster's New World College Dictionary, Fifth Edition, Copyright 2014 It is often ...

, and calf and bovine pneumonia * Urinary tract infections in dogs Horses are generally not treated with ampicillin, as they have low bioavailability of beta-lactams. The half-life in animals is around that same of that in humans (just over an hour). Oral absorption is less than 50% in cats and dogs, and less than 4% in horses.

References

External links

* * * * {{portal bar, Medicine Enantiopure drugs Penicillins Phenyl compounds World Health Organization essential medicines Wikipedia medicine articles ready to translate

Medical uses

Diseases

Bacteria

Available forms

Specific populations

Contraindications

Side effects

Overdose

Interactions

Pharmacology

Mechanism of action

Pharmacokinetics

History

Cost

Veterinary use

See also

References

External links