Amoxicillin#Names

Image:Amoxicillin.JPG]]

Amoxicillin is used in the treatment of a number of infections, including acute otitis media, streptococcal pharyngitis, pneumonia, skin infections, urinary tract infections, Salmonella infections, Lyme disease, and chlamydia infections.{{cite web | url = http://davisplus.fadavis.com/3976/meddeck/pdf/amoxicillin.pdf | access-date = 22 March 2017 | publisher = Davis | title = Amoxicillin | date = 2017 | url-status = live | archive-url = https://web.archive.org/web/20170908135951/https://davisplus.fadavis.com/3976/meddeck/pdf/amoxicillin.pdf | archive-date = 8 September 2017 }}

Children with acute otitis media who are younger than six months of age are generally treated with amoxicillin or other antibiotics. Although most children with acute otitis media who are older than two years old do not benefit from treatment with amoxicillin or other antibiotics, such treatment may be helpful in children younger than two years old with acute otitis media that is bilateral or accompanied by ear drainage.{{cite journal | vauthors = Venekamp RP, Sanders SL, Glasziou PP, Rovers MM | title = Antibiotics for acute otitis media in children | journal = The Cochrane Database of Systematic Reviews | volume = 11 | issue = 11 | pages = CD000219 | date = November 2023 | pmid = 37965923 | pmc = 10646935 | doi = 10.1002/14651858.CD000219.pub5 }} In the past, amoxicillin was dosed three times daily when used to treat acute otitis media, which resulted in missed doses in routine ambulatory practice. There is now evidence that two-times daily dosing or once-daily dosing has similar effectiveness.{{cite journal | vauthors = Thanaviratananich S, Laopaiboon M, Vatanasapt P | title = Once or twice daily versus three times daily amoxicillin with or without clavulanate for the treatment of acute otitis media | journal = The Cochrane Database of Systematic Reviews | issue = 12 | pages = CD004975 | date = December 2013 | volume = 2014 | pmid = 24338106 | doi = 10.1002/14651858.CD004975.pub3 | pmc = 10960641 }}

Most sinusitis infections are caused by viruses, for which amoxicillin and amoxicillin-clavulanate are ineffective,{{cite journal |title = Five Things Physicians and Patients Should Question |publisher = American Academy of Allergy, Asthma, and Immunology |journal = Choosing Wisely: An Initiative of the ABIM Foundation |url = http://choosingwisely.org/wp-content/uploads/2012/04/5things_12_factsheet_AAAAI.pdf |access-date = 14 August 2012 |url-status = live |archive-url = https://web.archive.org/web/20121103151124/http://choosingwisely.org/wp-content/uploads/2012/04/5things_12_factsheet_AAAAI.pdf |archive-date = 3 November 2012 }} and the small benefit gained by amoxicillin may be overridden by the adverse effects.{{cite journal | vauthors = Ahovuo-Saloranta A, Rautakorpi UM, Borisenko OV, Liira H, Williams JW, Mäkelä M | title = Antibiotics for acute maxillary sinusitis in adults | journal = The Cochrane Database of Systematic Reviews | issue = 2 | pages = CD000243 | date = February 2014 | pmid = 24515610 | doi = 10.1002/14651858.CD000243.pub3 | veditors = Ahovuo-Saloranta A }}

Amoxicillin is considered the first-line empirical treatment for most cases of uncomplicated bacterial sinusitis in children and adults when culture data is unavailable.{{cite web | vauthors = Patel ZM, Peter HH |title=Uncomplicated acute sinusitis and rhinosinusitis in adults: Treatment |url=https://www.uptodate.com/contents/uncomplicated-acute-sinusitis-and-rhinosinusitis-in-adults-treatment |url-status=live |archive-url=https://web.archive.org/web/20230313015138/https://www.uptodate.com/contents/uncomplicated-acute-sinusitis-and-rhinosinusitis-in-adults-treatment |archive-date=13 March 2023 |access-date=13 November 2023 |website=UpToDate}}{{cite Q|Q38897648}}{{cite Q|Q104102440}} Amoxicillin is recommended as the preferred first-line treatment for community-acquired pneumonia in adults by the National Institute for Health and Care Excellence, either alone (mild to moderate severity disease) or in combination with a macrolide.{{cite book|url=https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0071334/|title=Pneumonia: Diagnosis and Management of Community– and Hospital-Acquired Pneumonia in Adults |url-status=live|archive-url=https://web.archive.org/web/20170908135935/https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0071334/|archive-date=8 September 2017|publisher=National Institute for Health and Care Excellence (UK)|year=2014|series=National Institute for Health and Care Excellence: Clinical Guidelines, No. 191 |pmid=25520986 |author1=National Clinical Guideline Centre (UK) }} Research suggests that is as effective as co-amoxiclav (a broad-spectrum antibiotic) for people admitted to hospital with pneumonia, regardless of its severity.{{cite journal | vauthors = Wei J, Uppal A, Nganjimi C, Warr H, Ibrahim Y, Gu Q, Yuan H, Rahman NM, Jones N, Walker AS, Eyre DW | title = No evidence of difference in mortality with amoxicillin versus co-amoxiclav for hospital treatment of community-acquired pneumonia | language = English | journal = The Journal of Infection | volume = 88 | issue = 6 | pages = 106161 | date = June 2024 | pmid = 38663754 | doi = 10.1016/j.jinf.2024.106161 | pmc = 11893475 }}{{Cite journal |date=22 November 2024 |title=Amoxicillin is effective for many people hospitalised with pneumonia |url=https://evidence.nihr.ac.uk/alert/amoxicillin-is-effective-for-many-people-hospitalised-with-pneumonia/ |journal=NIHR Evidence}} The World Health Organization (WHO) recommends amoxicillin as first-line treatment for pneumonia that is not "severe".{{cite book|url=https://www.ncbi.nlm.nih.gov/books/NBK264162/|title=Revised WHO Classification and Treatment of Pneumonia in Children at Health Facilities - NCBI Bookshelf|url-status=live|archive-url=https://web.archive.org/web/20170908135935/https://www.ncbi.nlm.nih.gov/books/NBK264162/|archive-date=8 September 2017|isbn=978-92-4-150781-3|publisher=World Health Organization|year=2014|series=WHO Guidelines Approved by the Guidelines Review Committee|pmid=25535631 }} Amoxicillin is used in post-exposure inhalation of anthrax to prevent disease progression and for prophylaxis.

It is effective as one part of a multi-drug regimen for the treatment of stomach infections of Helicobacter pylori. It is typically combined with a proton-pump inhibitor (such as omeprazole) and a macrolide antibiotic (such as clarithromycin); other drug combinations are also effective.{{cite journal | vauthors = Chey WD, Leontiadis GI, Howden CW, Moss SF | title = ACG Clinical Guideline: Treatment of Helicobacter pylori Infection | journal = The American Journal of Gastroenterology | volume = 112 | issue = 2 | pages = 212–239 | date = February 2017 | pmid = 28071659 | doi = 10.1038/ajg.2016.563 | s2cid = 9390953 }}

Amoxicillin is effective for the treatment of early cutaneous Lyme borreliosis; the effectiveness and safety of oral amoxicillin is neither better nor worse than common alternatively-used antibiotics.{{cite journal | vauthors = Torbahn G, Hofmann H, Rücker G, Bischoff K, Freitag MH, Dersch R, Fingerle V, Motschall E, Meerpohl JJ, Schmucker C | title = Efficacy and Safety of Antibiotic Therapy in Early Cutaneous Lyme Borreliosis: A Network Meta-analysis | journal = JAMA Dermatology | volume = 154 | issue = 11 | pages = 1292–1303 | date = November 2018 | pmid = 30285069 | pmc = 6248135 | doi = 10.1001/jamadermatol.2018.3186 }}

Amoxicillin is used to treat odontogenic infections, infections of the tongue, lips, and other oral tissues. It may be prescribed following a tooth extraction, particularly in those with compromised immune systems.{{cite journal | vauthors = Tancawan AL, Pato MN, Abidin KZ, Asari AS, Thong TX, Kochhar P, Muganurmath C, Twynholm M, Barker K | title = Amoxicillin/Clavulanic Acid for the Treatment of Odontogenic Infections: A Randomised Study Comparing Efficacy and Tolerability versus Clindamycin | journal = International Journal of Dentistry | volume = 2015 | pages = 472470 | date = 2015 | pmid = 26300919 | pmc = 4537712 | doi = 10.1155/2015/472470 | doi-access = free }}

Amoxicillin is occasionally used for the treatment of skin infections, such as acne vulgaris.{{cite web | title = Adolescent Acne: Management | url = http://www.medscape.com/viewarticle/430534_5 | url-status = live | archive-url = https://web.archive.org/web/20101222205124/http://www.medscape.com/viewarticle/430534_5 | archive-date = 22 December 2010 }} It is often an effective treatment for cases of acne vulgaris that have responded poorly to other antibiotics, such as doxycycline and minocycline.{{cite web |url=http://scienceofacne.com/amoxicillin/ |title=Amoxicillin and Acne Vulgaris |publisher=scienceofacne.com |date=5 September 2012 |access-date=17 August 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120721002339/http://scienceofacne.com/amoxicillin/ |archive-date=21 July 2012 }}

Amoxicillin is recommended by the World Health Organization for the treatment of infants with signs and symptoms of pneumonia in resource-limited situations when the parents are unable or unwilling to accept hospitalization of the child. Amoxicillin in combination with gentamicin is recommended for the treatment of infants with signs of other severe infections when hospitalization is not an option.{{cite book|url=https://www.ncbi.nlm.nih.gov/books/NBK321136/|title=Guideline: Managing Possible Serious Bacterial Infection in Young Infants When Referral Is Not Feasible - NCBI Bookshelf|url-status=live|archive-url=https://web.archive.org/web/20170908135935/https://www.ncbi.nlm.nih.gov/books/NBK321136/|archive-date=8 September 2017|isbn=978-92-4-150926-8|publisher=World Health Organization|year=2015|series=WHO Guidelines Approved by the Guidelines Review Committee|pmid=26447263 }}

It is also used to prevent bacterial endocarditis and as a pain-reliever in high-risk people having dental work done, to prevent Streptococcus pneumoniae and other encapsulated bacterial infections in those without spleens, such as people with sickle-cell disease, and for both the prevention and the treatment of anthrax. The United Kingdom recommends against its use for infectious endocarditis prophylaxis.{{cite web|title=CG64 Prophylaxis against infective endocarditis: Full guidance |url=http://www.nice.org.uk/nicemedia/live/11938/40039/40039.pdf |work=NICE |access-date=8 June 2011 |url-status=dead |archive-url=https://web.archive.org/web/20111112000314/http://www.nice.org.uk/nicemedia/live/11938/40039/40039.pdf |archive-date=12 November 2011 }} These recommendations do not appear to have changed the rates of infection for infectious endocarditis.{{cite journal | vauthors = Thornhill MH, Dayer MJ, Forde JM, Corey GR, Chu VH, Couper DJ, Lockhart PB | title = Impact of the NICE guideline recommending cessation of antibiotic prophylaxis for prevention of infective endocarditis: before and after study | journal = BMJ | volume = 342 | pages = d2392 | date = May 2011 | pmid = 21540258 | pmc = 3086390 | doi = 10.1136/bmj.d2392 }}

{{Main|Amoxicillin/clavulanic acid}}

Amoxicillin is susceptible to degradation by β-lactamase-producing bacteria, which are resistant to most β-lactam antibiotics, such as penicillin. For this reason, it may be combined with clavulanic acid, a β-lactamase inhibitor. This drug combination is commonly called co-amoxiclav.{{cite web|title=Amoxicillin Susceptibility and Resistance Data|url=http://www.toku-e.com/Assets/MIC/AmoxicillinClavulanate%20augmentin.pdf|access-date=20 July 2013|archive-url=https://web.archive.org/web/20190713141750/http://www.toku-e.com/Assets/MIC/AmoxicillinClavulanate%20augmentin.pdf|archive-date=13 July 2019|url-status=dead}}

It is a moderate-spectrum, bacteriolytic, β-lactam antibiotic in the aminopenicillin family used to treat susceptible Gram-positive and Gram-negative bacteria. It is usually the drug of choice within the class because it is better absorbed, following oral administration, than other β-lactam antibiotics.

In general, Streptococcus, Bacillus subtilis, Enterococcus, Haemophilus, Helicobacter, and Moraxella are susceptible to amoxicillin, whereas Citrobacter, Klebsiella and Pseudomonas aeruginosa are resistant to it.{{cite web|title=Amoxicillin spectrum of bacterial susceptibility and Resistance|url=http://www.toku-e.com/Assets/MIC/Amoxicillin%20sodium%20salt.pdf|access-date=8 April 2012|archive-url=https://web.archive.org/web/20181222141136/http://www.toku-e.com/Assets/MIC/Amoxicillin%20sodium%20salt.pdf|archive-date=22 December 2018|url-status=dead}} Some E. coli and most clinical strains of Staphylococcus aureus have developed resistance to amoxicillin to varying degrees.{{cite journal | vauthors = Tadesse BT, Ashley EA, Ongarello S, Havumaki J, Wijegoonewardena M, González IJ, Dittrich S | title = Antimicrobial resistance in Africa: a systematic review | journal = BMC Infectious Diseases | volume = 17 | issue = 1 | pages = 616 | date = September 2017 | pmid = 28893183 | pmc = 5594539 | doi = 10.1186/s12879-017-2713-1 | doi-access = free }}

Adverse effects are similar to those for other β-lactam antibiotics, including nausea, vomiting, rashes, and antibiotic-associated colitis. Diarrhea (loose bowel movements) may also occur.

Rarer adverse effects include mental and behavioral changes, lightheadedness, insomnia, hyperactivity, agitation, confusion, anxiety, sensitivity to lights and sounds, and unclear thinking.{{cite journal | vauthors = Esposito S, Canevini MP, Principi N | title = Complications associated with antibiotic administration: neurological adverse events and interference with antiepileptic drugs | journal = Int J Antimicrob Agents | volume = 50 | issue = 1 | pages = 1–8 | date = July 2017 | pmid = 28414069 | doi = 10.1016/j.ijantimicag.2017.01.027 | url = | quote = Benzylpenicillin, the most neurotoxic among the penicillins, has often been associated with the development of encephalopathy and seizures both in animals and humans [21], [22]. However, some neurological adverse effects (anxiety, hyperactivity, confusion, convulsions, and behavioural changes) have also been reported for amoxicillin and ampicillin, the two penicillins with the lowest risk of neurotoxicity [22], [23], [24], [25], [26], [27]. Moreover, ampicillin may cause seizures when administered to very low-birth-weight neonates [28].}}{{cite journal | vauthors = Jang HM, Lee HJ, Jang SE, Han MJ, Kim DH | title = Evidence for interplay among antibacterial-induced gut microbiota disturbance, neuro-inflammation, and anxiety in mice | journal = Mucosal Immunol | volume = 11 | issue = 5 | pages = 1386–1397 | date = September 2018 | pmid = 29867078 | doi = 10.1038/s41385-018-0042-3 | url = | quote = However, treatment with amoxicillin has been reported to cause adverse neurological effects such as anxiety, hyperactivity, confusion, and behavioral changes as side effects in children.21| doi-access = free }} Immediate medical care is required upon the first signs of these adverse effects. Similarly to other penicillins, amoxicillin has been associated with an increased risk of seizures.{{cite journal | vauthors = Nestor MA, Ryan M, Cook AM | title = Catching the seizure culprit: drugs on the differential | journal = Orthopedics | volume = 33 | issue = 9 | pages = 679–682 | date = September 2010 | pmid = 20839747 | doi = 10.3928/01477447-20100722-16 | url = | quote = }}{{cite journal | vauthors = Atli O, Demir-Ozkay U, Ilgin S, Aydin TH, Akbulut EN, Sener E | title = Evidence for neurotoxicity associated with amoxicillin in juvenile rats | journal = Hum Exp Toxicol | volume = 35 | issue = 8 | pages = 866–876 | date = August 2016 | pmid = 26429924 | doi = 10.1177/0960327115607948 | bibcode = 2016HETox..35..866A | url = | quote = Till date, limited number of acute psychiatric adverse events (including seizure, encephalopathy, and tremor) related to AMX treatment have been reported in patients with no underlying psychiatric disorders.11–15 Furthermore, the Food and Drug Administration has published a report that when AMX was coadministered with cephalosporin, this combination therapy might cause death by inducing seizures in a patient.16}} Amoxicillin-induced neurotoxicity has been especially associated with concentrations of greater than 110{{nbsp}}mg/L.{{cite journal | vauthors = Lalanne S, Bouzillé G, Tron C, Revest M, Polard E, Bellissant E, Verdier MC, Lemaitre F | title = Amoxicillin-Induced Neurotoxicity: Contribution of a Healthcare Data Warehouse to the Determination of a Toxic Concentration Threshold | journal = Antibiotics | volume = 12 | issue = 4 | date = March 2023 | page = 680 | pmid = 37107042 | pmc = 10135267 | doi = 10.3390/antibiotics12040680 | doi-access = free | url = }}

The onset of an allergic reaction to amoxicillin can be very sudden and intense; emergency medical attention must be sought as quickly as possible. The initial phase of such a reaction often starts with a change in mental state, skin rash with intense itching (often beginning in the fingertips and around the groin area and rapidly spreading), and sensations of fever, nausea, and vomiting. Any other symptoms that seem even remotely suspicious must be taken very seriously. However, more mild allergy symptoms, such as a rash, can occur at any time during treatment, even up to a week after treatment has ceased. For some people allergic to amoxicillin, the adverse effects can be fatal due to anaphylaxis.

Use of the amoxicillin/clavulanic acid combination for more than one week has caused a drug-induced immunoallergic-type hepatitis in some patients. Young children having ingested acute overdoses of amoxicillin manifested lethargy, vomiting, and renal dysfunction.{{cite journal | vauthors = Cundiff J, Joe S | title = Amoxicillin-clavulanic acid-induced hepatitis | journal = American Journal of Otolaryngology | volume = 28 | issue = 1 | pages = 28–30 | date = January 2007 | pmid = 17162128 | doi = 10.1016/j.amjoto.2006.06.007 }}{{cite book | vauthors = Baselt R | title = Disposition of Toxic Drugs and Chemicals in Man | edition = 8th | publisher = Biomedical Publications | location = Foster City, CA | year = 2008 | pages = 81–83}}

There is poor reporting of adverse effects of amoxicillin from clinical trials. For this reason, the severity and frequency of adverse effects from amoxicillin are probably higher than reported in clinical trials.

Between 3 and 10% of children taking amoxicillin (or ampicillin) show a late-developing (>72 hours after beginning medication and having never taken penicillin-like medication previously) rash, which is sometimes referred to as the "amoxicillin rash". The rash can also occur in adults and may rarely be a component of the DRESS syndrome.{{cite web |title=Amoxicillin Rash |url=https://hhma.org/healthadvisor/pa-ampirash-hhg/ |website=Tufts Medical Center |publisher=Tufts Medicine MelroseWakefield Hospital |access-date=24 June 2023 |archive-date=25 June 2023 |archive-url=https://web.archive.org/web/20230625145658/https://hhma.org/healthadvisor/pa-ampirash-hhg/ |url-status=dead }}

The rash is described as maculopapular or morbilliform (measles-like; therefore, in medical literature, it is called "amoxicillin-induced morbilliform rash".{{cite journal | vauthors = Barbaud AM, Béné MC, Schmutz JL, Ehlinger A, Weber M, Faure GC | title = Role of delayed cellular hypersensitivity and adhesion molecules in amoxicillin-induced morbilliform rashes | journal = Archives of Dermatology | volume = 133 | issue = 4 | pages = 481–6 | date = April 1997 | pmid = 9126012 | doi = 10.1001/archderm.1997.03890400081011 | id = {{INIST|2654598}} }}). It starts on the trunk and can spread from there. This rash is unlikely to be a true allergic reaction and is not a contraindication for future amoxicillin usage, nor should the current regimen necessarily be stopped. However, this common amoxicillin rash and a dangerous allergic reaction cannot easily be distinguished by inexperienced persons, so a healthcare professional is often required to distinguish between the two.{{cite journal | vauthors = Pichichero ME | title = A review of evidence supporting the American Academy of Pediatrics recommendation for prescribing cephalosporin antibiotics for penicillin-allergic patients | journal = Pediatrics | volume = 115 | issue = 4 | pages = 1048–57 | date = April 2005 | pmid = 15805383 | doi = 10.1542/peds.2004-1276 | s2cid = 21246804 }}{{cite book | vauthors = Schmitt BD |title=Your child's health: the parents' one-stop reference guide to symptoms, emergencies, common illnesses, behavior problems, healthy development |edition=2nd |publisher=Bantam Books |location=New York |year=2005 |isbn=978-0-553-38369-0 |url-access=registration |url=https://archive.org/details/yourchildshealth00bart }}

A nonallergic amoxicillin rash may also be an indicator of infectious mononucleosis. Some studies indicate about 80–90% of patients with acute Epstein–Barr virus infection treated with amoxicillin or ampicillin develop such a rash.{{cite journal | vauthors = Kagan BM | title = Ampicillin rash | journal = The Western Journal of Medicine | volume = 126 | issue = 4 | pages = 333–5 | date = April 1977 | pmid = 855325 | pmc = 1237570 }}

Image:Amoxicillin rash 3 hours after 17th dose.JPG|Nonallergic amoxicillin rash eight days after first dose: This photo was taken 24 hours after the rash began.

Image:Amoxicillin rash 11 hours after 17th dose.JPG|Eight hours after the first photo, individual spots have grown and begun to merge.

Image:Amoxicillin rash 26 hours after 17th dose.JPG|At 23 hours after the first photo, the color appears to be fading, and much of rash has spread to confluence.

Amoxicillin may interact with these drugs:

• Anticoagulants (dabigatran, warfarin).British National Formulary 57 March 2009{{Citation | vauthors = Reis W, Gaio J, Trang T, Reis H, Tang J, Juma H, Ramos F, Santos HD, Reis C |title=Antibiotics |date=2020 |url=https://doi.org/10.1007/978-981-15-3591-8_10 | veditors = Prabhakar H, Mahajan C, Kapoor I |work=Pharmacology in Clinical Neurosciences: A Quick Guide |pages=265–497 |access-date=9 April 2023 |place=Singapore |publisher=Springer |doi=10.1007/978-981-15-3591-8_10 |isbn=978-981-15-3591-8 |url-access=subscription }}
• Methotrexate (chemotherapy and immunosuppressant).
• Typhoid, Cholera and BCG vaccines.{{cite book | vauthors = Arcangelo VP, Peterson AM, Wilbur V, Reinhold JA | date=17 August 2016 | publisher=LWW | title=Pharmacotherapeutics for Advanced Practice: A Practical Approach | url=https://books.google.com/books?id=FBJRDAAAQBAJ&pg=PT770 | isbn=978-1-496-31996-8}}
• Probenecid reduces renal excretion and increases blood levels of amoxicillin.
• Oral contraceptives potentially become less effective.{{cite journal | vauthors = Zhanel GG, Siemens S, Slayter K, Mandell L | title = Antibiotic and oral contraceptive drug interactions: Is there a need for concern? | journal = The Canadian Journal of Infectious Diseases | volume = 10 | issue = 6 | pages = 429–433 | date = November 1999 | pmid = 22346401 | pmc = 3250726 | doi = 10.1155/1999/539376 | doi-access = free }}
• Allopurinol (gout treatment).{{Citation | vauthors = Comeau D, Heaton K, Gordon A |title=Chapter 32 - Rheumatology and Musculoskeletal Problems |date= January 2012 | veditors = Rakel RE, Rakel DP |work=Textbook of Family Medicine | edition = Eighth |pages=648–689 |place=Philadelphia |publisher=W.B. Saunders |doi=10.1016/b978-1-4377-1160-8.10032-6 |isbn=978-1-4377-1160-8 }}
• Mycophenolate (immunosuppressant)

When given intravenously or intramuscularly:

• It should not be mixed with blood products, or proteinaceous fluids (including protein hydrolysates) or with intravenous lipid emulsions
• aminoglycoside should be injected at a separate site from amoxicillin if the patient is prescribed both medications at the same time. Neither drug should be mixed in a syringe. Neither should they be mixed in an intravenous fluid container or giving set because of loss of activity of the aminoglycoside under these conditions.
• ciprofloxacin should not be mixed with amoxicillin.
• Infusions containing dextran or bicarbonate should not be mixed with amoxicillin solutions.

Amoxicillin (α-amino-p-hydroxybenzyl penicillin) is a semisynthetic derivative of penicillin with a structure similar to ampicillin but with better absorption when taken by mouth, thus yielding higher concentrations in blood and in urine.{{cite journal | vauthors = Handsfield HH, Clark H, Wallace JF, Holmes KK, Turck M | title = Amoxicillin, a new penicillin antibiotic | journal = Antimicrobial Agents and Chemotherapy | volume = 3 | issue = 2 | pages = 262–5 | date = February 1973 | pmid = 4208282 | pmc = 444397 | doi = 10.1128/AAC.3.2.262 }} Amoxicillin diffuses easily into tissues and body fluids. It will cross the placenta and is excreted into breastmilk in small quantities. It is metabolized by the liver and excreted into the urine. It has an onset of 30 minutes and a half-life of 3.7 hours in newborns and 1.4 hours in adults.

Amoxicillin attaches to the cell wall of susceptible bacteria and results in their death. It is effective against streptococci, pneumococci, enterococci, Haemophilus influenzae, Escherichia coli, Proteus mirabilis, Neisseria meningitidis, Neisseria gonorrhoeae, Shigella, Chlamydia trachomatis, Salmonella, Borrelia burgdorferi, and Helicobacter pylori. As a derivative of ampicillin, amoxicillin is a member of the penicillin family and, like penicillins, is a β-lactam antibiotic.{{cite book | vauthors = Alcamo IE |year=2003 |title=Microbes and Society: An Introduction to Microbiology |publisher=Jones & Bartlett Learning |page=198 |url=https://books.google.com/books?id=oRAZd3AlTlkC&pg=PA198 |isbn=978-0-7637-1430-7 }} It inhibits cross-linkage between the linear peptidoglycan polymer chains that make up a major component of the bacterial cell wall. It has two ionizable groups in the physiological range (the amino group in alpha-position to the amide carbonyl group and the carboxyl group).{{cite book|url=https://books.google.com/books?id=XiShDwAAQBAJ&pg=PA423|veditors=Sezer AD|publisher=INTECH|isbn=978-953-51-1628-8|title=Application of Nanotechnology in Drug Delivery|date=2016|page=423|access-date=24 July 2019|archive-date=12 January 2023|archive-url=https://web.archive.org/web/20230112005951/https://books.google.com/books?id=XiShDwAAQBAJ&pg=PA423|url-status=live}}

Amoxicillin is a β-lactam and aminopenicillin antibiotic in terms of chemical structure.{{cite journal | vauthors = Wright AJ | title = The penicillins | journal = Mayo Clin Proc | volume = 74 | issue = 3 | pages = 290–307 | date = March 1999 | pmid = 10090000 | doi = 10.4065/74.3.290 | url = }} It is structurally related to ampicillin.

The experimental log P of amoxicillin is 0.87.{{cite journal | vauthors = Jafari Ozumchelouei E, Hamidian AH, Zhang Y, Yang M | title = Physicochemical properties of antibiotics: A review with an emphasis on detection in the aquatic environment | journal = Water Environ Res | volume = 92 | issue = 2 | pages = 177–188 | date = February 2020 | pmid = 31505071 | doi = 10.1002/wer.1237 | bibcode = 2020WaEnR..92..177J | url = }}{{cite web | title=Amoxicillin | website=PubChem | url=https://pubchem.ncbi.nlm.nih.gov/compound/33613 | access-date=15 October 2024}} It is described as an "ambiphilic"—between hydrophilic and lipophilic—antibiotic.{{cite journal | vauthors = Nguyen PT, Le NV, Dinh HM, Nguyen BQ, Nguyen TV | title = Lung penetration and pneumococcal target binding of antibiotics in lower respiratory tract infection | journal = Curr Med Res Opin | volume = 38 | issue = 12 | pages = 2085–2095 | date = December 2022 | pmid = 36189961 | doi = 10.1080/03007995.2022.2131304 | url = }}

{{See also|Timeline of antibiotics}}

Amoxicillin was one of several semisynthetic derivatives of 6-aminopenicillanic acid (6-APA) developed by the Beecham Group in the 1960s. It was invented by Anthony Alfred Walter Long and John Herbert Charles Nayler, two British scientists.{{cite patent |country=GB |number=978178 |status=patent |title=Penicillins |pubdate=1964-12-16 |fdate=1962-11-02 |pridate=1962-11-02 |inventor=Nayler JH, Smith H |assign1=Beecham Research Laboratories Ltd |url=https://worldwide.espacenet.com/publicationDetails/biblio?CC=GB&NR=978178A&KC=A&FT=D&ND=&date=19641216&DB=&locale=en_EP }}{{Dead link|date=June 2025 |bot=InternetArchiveBot |fix-attempted=yes }}{{cite patent |country=GB |number=1241844 |status=patent |title=Penicillins |pubdate=1971-08-04 |fdate=1968-08-23 |pridate=1968-08-23 |inventor=Long AA, Nayler JH |assign1=Beecham Group LTD |url=https://worldwide.espacenet.com/publicationDetails/biblio?CC=GB&NR=1241844&KC=&FT=E&locale=en_EP }}{{Dead link|date=June 2025 |bot=InternetArchiveBot |fix-attempted=yes }} It became available in 1972 and was the second aminopenicillin to reach the market (after ampicillin in 1961).{{cite journal | vauthors = Geddes AM, Klugman KP, Rolinson GN | title = Introduction: historical perspective and development of amoxicillin/clavulanate | journal = International Journal of Antimicrobial Agents | volume = 30 | issue = Suppl 2 | pages = S109-12 | date = December 2007 | pmid = 17900874 | doi = 10.1016/j.ijantimicag.2007.07.015 }}{{cite book | vauthors = Raviña E |title=The Evolution of Drug Discovery |publisher=Wiley-VCH |location=Weinheim |year=2014 |page=262 |isbn=978-3-527-32669-3}}{{cite book | vauthors = Bruggink A |title=Synthesis of β-lactam antibiotics |publisher=Springer |year=2001 |page=17 |isbn=978-0-7923-7060-4}} Co-amoxiclav became available in 1981.

Amoxicillin is relatively inexpensive.{{cite book |vauthors=Hanno PM, Guzzo TJ, Malkowicz SB, Wein AJ |title=Penn Clinical Manual of Urology E-Book |date=2014 |publisher=Elsevier Health Sciences |isbn=978-0-323-24466-4 |page=122 |url=https://books.google.com/books?id=OQTbAgAAQBAJ&pg=PA122 |access-date=18 March 2023 |archive-date=14 April 2023 |archive-url=https://web.archive.org/web/20230414211301/https://books.google.com/books?id=OQTbAgAAQBAJ&pg=PA122 |url-status=live }} In 2022, a survey of eight generic antibiotics commonly prescribed in the United States found their average cost to be about $42.67, while amoxicillin was sold for $12.14 on average.{{cite web | url=https://www.talktomira.com/post/how-much-antibiotics-cost-without-insurance | title=How Much Do Antibiotics Cost Without Insurance in 2021? | access-date=4 December 2022 | archive-date=4 December 2022 | archive-url=https://web.archive.org/web/20221204114959/https://www.talktomira.com/post/how-much-antibiotics-cost-without-insurance | url-status=live }}

Pharmaceutical manufacturers make amoxicillin in trihydrate form, for oral use available as capsules, regular, chewable and dispersible tablets, syrup and pediatric suspension for oral use, and as the sodium salt for intravenous administration.{{medical citation needed|date=September 2022}}

An extended-release is available.{{cite web | url=https://www.accessdata.fda.gov/drugsatfda_docs/nda/2008/050813_moxatag_toc.cfm | title=Drug Approval Package: Moxatag (amoxicillin extended-release) NDA #050813 | access-date=25 December 2018 | archive-date=3 December 2019 | archive-url=https://web.archive.org/web/20191203114048/https://www.accessdata.fda.gov/drugsatfda_docs/nda/2008/050813_moxatag_toc.cfm | url-status=dead }} The intravenous form of amoxicillin is not sold in the United States.{{cite book| vauthors = Marek CL, Timmons SR |title=Pediatric Dentistry: Infancy Through Adolescence| veditors = Nowak A |date=2018|isbn=978-0-323-60826-8|publisher=Saunders}} When an intravenous aminopenicillin is required in the United States, ampicillin is typically used. When there is an adequate response to ampicillin, the course of antibiotic therapy may often be completed with oral amoxicillin.{{cite web|url=https://www.safetyandquality.gov.au/wp-content/uploads/2012/02/4.3-A-Quick-Guide-to-Switch_Southern-Health.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.safetyandquality.gov.au/wp-content/uploads/2012/02/4.3-A-Quick-Guide-to-Switch_Southern-Health.pdf |archive-date=9 October 2022 |url-status=live|title=A Quick Guide to Switch : Antibiotics: IV to Oral|website=Safetyandquality.gov.au|access-date=1 March 2022}}

Research with mice indicated successful delivery using intraperitoneally injected amoxicillin-bearing microparticles.{{cite journal | vauthors = Farazuddin M, Chauhan A, Khan RM, Owais M | title = Amoxicillin-bearing microparticles: potential in the treatment of Listeria monocytogenes infection in Swiss albino mice | journal = Bioscience Reports | volume = 31 | issue = 4 | pages = 265–72 | date = August 2011 | pmid = 20687896 | doi = 10.1042/BSR20100027 }}

Amoxicillin is the international nonproprietary name (INN),{{cite web |title=Amoxicillin [INN] |url=https://pubchem.ncbi.nlm.nih.gov/substance/134997708 |website=pubchem.ncbi.nlm.nih.gov |access-date=3 June 2024 }} British Approved Name (BAN), and United States Adopted Name (USAN), while amoxycillin is the Australian Approved Name (AAN).{{citation needed|date=September 2022}}

Amoxicillin is one of the semisynthetic penicillins discovered by the former pharmaceutical company Beecham Group. The patent for amoxicillin has expired, thus amoxicillin and co-amoxiclav preparations are marketed under various brand names across the world.{{cite web|title=International brand names for amoxicillin|url=https://www.drugs.com/international/amoxicillin.html|website=Drugs.com|access-date=15 November 2016|url-status=deviated |archive-url=https://web.archive.org/web/20160529051432/http://www.drugs.com/international/amoxicillin.html|archive-date=29 May 2016}}

Amoxicillin is also sometimes used as an antibiotic for animals. The use of amoxicillin for animals intended for human consumption (chickens, cattle, and swine for example) has been approved.{{cite web | vauthors = Ramos F, Boison J, Friedlander LG |title=Amoxicillin |url=http://www.fao.org/fileadmin/user_upload/vetdrug/docs/12-2012-amoxicillin.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.fao.org/fileadmin/user_upload/vetdrug/docs/12-2012-amoxicillin.pdf |archive-date=9 October 2022 |url-status=live |website=fao.org |publisher=Food and Agriculture Organization of the United Nations |access-date=8 November 2019}}

{{Reflist}}

• {{cite book | vauthors = Neal MJ |year=2002 |title=Medical Pharmacology at a Glance |edition=4th |location=Oxford |publisher=Blackwell Science |isbn=978-0-632-05244-8 }}

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