Amoxicillin: Difference between revisions

{{Short description|Beta-lactam antibiotic}}

{{distinguish|Ampicillin}}

{{Use dmy dates|date=January 2024}}

{{cs1 config|mode=cs1 |name-list-style=vanc |display-authors=6}}

{{Infobox drug

| Watchedfields = changed

| verifiedrevid = 455343638

| image = Amoxicillin.svg

| width =

| alt =

| caption =

| image2 = Amoxicillin-from-xtal-3D-bs-17.png

| width2 =

| alt2 =

| AAN = Amoxycillin

<!-- Clinical data -->

| pronounce = {{IPAc-en|ə|ˌ|m|ɒ|k|s|ᵻ|ˈ|s|ɪ|l|ᵻ|n}}

| tradename = Amoxil, Trimox, others<ref name=brands/>

| Drugs.com = {{drugs.com|monograph|amoxicillin}}

| MedlinePlus = a685001

| DailyMedID = Amoxicillin

| pregnancy_AU = A

| pregnancy_AU_comment =

| pregnancy_category =

| routes_of_administration = [[Oral administration|By mouth]], [[intravenous therapy|intravenous]]

| class = [[β-lactam]] antibiotic, [[aminopenicillin]]

| ATC_prefix = J01

| ATC_suffix = CA04

| ATC_supplemental = {{ATCvet|G51|AA03}}

<!-- Legal status -->

| legal_AU = S4

| legal_AU_comment =

| legal_BR = <!-- OTC, A1, A2, A3, B1, B2, C1, C2, C3, C4, C5, D1, D2, E, F -->

| legal_BR_comment =

| legal_CA = Rx-only

| legal_CA_comment =

| legal_DE = <!-- Anlage I, II, III or Unscheduled -->

| legal_DE_comment =

| legal_NZ = <!-- Class A, B, C -->

| legal_NZ_comment =

| legal_UK = POM

| legal_UK_comment = <ref name="Amoxil SmPC">{{cite web | title=Amoxil Vials for Injection 500mg - Summary of Product Characteristics (SmPC) | website=(emc) | date=4 November 2021 | url=https://www.medicines.org.uk/emc/product/94/smpc | access-date=8 October 2022 | archive-date=10 October 2022 | archive-url=https://web.archive.org/web/20221010025443/https://www.medicines.org.uk/emc/product/94/smpc | url-status=dead }}</ref>

| legal_US = Rx-only

| legal_US_comment = <ref name="Amoxil FDA label">{{cite web | title=Amoxil (amoxicillin) Capsules, Tablets, Chewable Tablets, and Powder for Oral Suspension | website=DailyMed | url=https://dailymed.nlm.nih.gov/dailymed/archives/fdaDrugInfo.cfm?archiveid=49302 | access-date=8 October 2022}}</ref><ref name="Amoxil FDA approval">{{cite web | title=Amoxil: FDA-Approved Drugs | website=U.S. [[Food and Drug Administration]] (FDA) | url=https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=050459 | access-date=8 October 2022}}</ref><ref name="Trimox FDA approval">{{cite web | title=Trimox: FDA-Approved Drugs | website=U.S. [[Food and Drug Administration]] (FDA) | url=https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=061885 | access-date=8 October 2022}}</ref><ref name="Moxatag FDA label">{{cite web | title=Moxatag (amoxicillin extended-release) Tablets Initial U.S. Approval: 1974 | website=DailyMed | url=https://dailymed.nlm.nih.gov/dailymed/archives/fdaDrugInfo.cfm?archiveid=364489 | access-date=8 October 2022}}</ref>

| legal_UN = <!-- N I, II, III, IV / P I, II, III, IV -->

| legal_UN_comment =

| legal_status = Rx-only

<!-- Pharmacokinetic data -->

| bioavailability = 95% by mouth

| protein_bound =

| metabolism = less than 30% biotransformed in [[liver]]

| metabolites =

| onset =

| duration_of_action =

| excretion = [[Kidneys]]

<!-- Identifiers -->

| CAS_number_Ref = {{cascite|correct|??}}

| CAS_number = 26787-78-0

| CAS_supplemental =

| PubChem = 33613

| IUPHAR_ligand =

| DrugBank_Ref = {{drugbankcite|correct|drugbank}}

| DrugBank = DB01060

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 31006

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = 9EM05410Q9

| KEGG_Ref = {{keggcite|correct|kegg}}

| KEGG = D07452

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 2676

| ChEMBL_Ref = {{ebicite|correct|EBI}}

| ChEMBL = 1082

| NIAID_ChemDB =

| PDB_ligand =

| synonyms = Amoxycillin, amox

<!-- Chemical and physical data -->

| IUPAC_name = (2''S'',5''R'',6''R''<nowiki>)-6-{[(2</nowiki>''R'')-2-Amino-2-(4-hydroxyphenyl)acetyl]amino}-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid

| C = 16

| H = 19

| N = 3

| O = 5

| S = 1

| SMILES = O=C(O)[C@@H]2N3C(=O)[C@@H](NC(=O)[C@@H](c1ccc(O)cc1)N)[C@H]3SC2(C)C

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/C16H19N3O5S/c1-16(2)11(15(23)24)19-13(22)10(14(19)25-16)18-12(21)9(17)7-3-5-8(20)6-4-7/h3-6,9-11,14,20H,17H2,1-2H3,(H,18,21)(H,23,24)/t9-,10-,11+,14-/m1/s1

| StdInChI_comment =

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = LSQZJLSUYDQPKJ-NJBDSQKTSA-N

| density = 1.6±0.1 <ref name="chemsrc">{{cite web|url=https://www.chemsrc.com/en/cas/26787-78-0_946616.html|title=Amoxicillin|website=www.chemsrc.com}}</ref>

| density_notes =

| melting_point =

| melting_high =

| melting_notes =

| boiling_point =

| boiling_notes =

| solubility =

| sol_units =

| specific_rotation =

<!-- Definition and uses -->

'''Amoxicillin''' is an [[antibiotic]] medication belonging to the [[aminopenicillin]] class of the [[penicillin]] family. The drug is used to treat [[bacterial infection]]s<ref name="AHFS2015" /> such as [[acute otitis media|middle ear infection]], [[strep throat]], [[pneumonia]], [[cellulitis|skin infections]], [[odontogenic infections]], and [[urinary tract infection]]s.<ref name=AHFS2015/> It is taken [[oral administration|by mouth]], or less commonly by injection.<ref name=AHFS2015>{{cite web|title=Amoxicillin|url=https://www.drugs.com/amoxicillin.html|publisher=Drugs.com, The American Society of Health-System Pharmacists|access-date=24 November 2022|date=3 January 2022}}</ref><ref>{{cite web|title=Amoxicillin Sodium for Injection|url=https://www.medicines.org.uk/emc/medicine/5359|website=EMC|access-date=26 October 2016|date=10 February 2016|url-status=live|archive-url=https://web.archive.org/web/20161027054630/https://www.medicines.org.uk/emc/medicine/5359|archive-date=27 October 2016}}</ref>

<!-- Adverse effects and mechanism -->

Common adverse effects include nausea and rash.<ref name=AHFS2015/> It may also increase the risk of [[candidiasis|yeast infections]] and, when used in combination with [[clavulanic acid]], [[diarrhea]].<ref name="Common harms from amoxicillin: a sy">{{cite journal | vauthors = Gillies M, Ranakusuma A, Hoffmann T, Thorning S, McGuire T, Glasziou P, Del Mar C | title = Common harms from amoxicillin: a systematic review and meta-analysis of randomized placebo-controlled trials for any indication | journal = CMAJ | volume = 187 | issue = 1 | pages = E21–E31 | date = January 2016| pmid = 25404399 | pmc = 4284189 | doi = 10.1503/cmaj.140848 }}</ref> It should not be used in those who are allergic to [[penicillin]].<ref name=AHFS2015/> While usable in those with [[kidney problem]]s, the [[Dose (biochemistry)|dose]] may need to be decreased.<ref name=AHFS2015/> Its use in [[pregnancy]] and [[breastfeeding]] does not appear to be harmful.<ref name=AHFS2015/> Amoxicillin is in the [[Beta-lactam antibiotics|β-lactam family of antibiotics]].<ref name=AHFS2015/>

<!-- Society and culture -->

Amoxicillin was discovered in 1958 and came into medical use in 1972.<ref>{{cite book| vauthors = Fischer J, Ganellin CR |title=Analogue-based Drug Discovery|date=2006|publisher=John Wiley & Sons|isbn=978-3-527-60749-5|page=490|url=https://books.google.com/books?id=FjKfqkaKkAAC&pg=PA490|url-status=live|archive-url=https://web.archive.org/web/20170908135935/https://books.google.com/books?id=FjKfqkaKkAAC&pg=PA490|archive-date=8 September 2017}}</ref><ref>{{cite book| vauthors = Roy J |title=An introduction to pharmaceutical sciences production, chemistry, techniques and technology|date=2012|publisher=Woodhead Pub.|location=Cambridge|isbn=978-1-908818-04-1|page=239|url=https://books.google.com/books?id=0IdmAgAAQBAJ&pg=PA239|url-status=live|archive-url=https://web.archive.org/web/20170908135935/https://books.google.com/books?id=0IdmAgAAQBAJ&pg=PA239|archive-date=8 September 2017}}</ref> Amoxil was approved for medical use in the United States in 1974,<ref name="Amoxil FDA approval" /><ref name="Trimox FDA approval" /> and in the United Kingdom in 1977.<ref name="Amoxil SmPC" /> It is on the (WHO) [[WHO Model List of Essential Medicines|World Health Organization's List of Essential Medicines]].<ref name="WHO21st">{{cite book | vauthors = ((World Health Organization)) | title = World Health Organization model list of essential medicines: 21st list 2019 | year = 2019 | hdl = 10665/325771 | author-link = World Health Organization | publisher = World Health Organization | location = Geneva | id = WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO | hdl-access=free }}</ref><ref name="WHO22nd">{{cite book | vauthors = ((World Health Organization)) | title = World Health Organization model list of essential medicines: 22nd list (2021) | year = 2021 | hdl = 10665/345533 | author-link = World Health Organization | publisher = World Health Organization | location = Geneva | id = WHO/MHP/HPS/EML/2021.02 | hdl-access=free }}</ref> It is one of the most commonly prescribed antibiotics in children.<ref>{{cite book| vauthors = Kelly D |title=Diseases of the liver and biliary system in children|date=2008|publisher=Wiley-Blackwell|location=Chichester, UK|isbn=978-1-4443-0054-3|page=217|edition=3|url=https://books.google.com/books?id=z7nO3OrNXckC&pg=PA217|url-status=live|archive-url=https://web.archive.org/web/20170908135935/https://books.google.com/books?id=z7nO3OrNXckC&pg=PA217|archive-date=8 September 2017}}</ref> Amoxicillin is available as a [[generic medication]].<ref name=AHFS2015/> In 2021, it was the 38th most commonly prescribed medication in the United States, with more than 16{{nbsp}}million prescriptions.<ref>{{cite web | title=The Top 300 of 2021 | url=https://clincalc.com/DrugStats/Top300Drugs.aspx | website=ClinCalc | access-date=14 January 2024 | archive-date=15 January 2024 | archive-url=https://web.archive.org/web/20240115223848/https://clincalc.com/DrugStats/Top300Drugs.aspx | url-status=live }}</ref><ref>{{cite web | title = Amoxicillin - Drug Usage Statistics | website = ClinCalc | url = https://clincalc.com/DrugStats/Drugs/Amoxicillin | access-date = 14 January 2024}}</ref>

[[Image:Amoxicillin.JPG|thumb|right|Amoxicillin [[British Pharmacopoeia|BP]]]]

Amoxicillin is used in the treatment of a number of infections, including [[acute otitis media]], [[streptococcal pharyngitis]], [[pneumonia]], [[Cellulitis|skin infections]], [[urinary tract infection]]s, ''[[Salmonella]]'' infections, [[Lyme disease]], and [[Chlamydia infection|chlamydia]] infections.<ref name=AHFS2015/><ref name=Davisamox>{{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 }}</ref>

===Acute otitis media===

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.<ref>{{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 | pmc-embargo-date = 15 November 2024 }}</ref> In the past, amoxicillin was dosed three times daily when used to treat acute otitis media, which resulted in missed doses in routine [[Ambulatory care|ambulatory practice]]. There is now evidence that two times daily dosing or once daily dosing has similar effectiveness.<ref>{{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 | pmid = 24338106 | doi = 10.1002/14651858.CD004975.pub3 | pmc = 10960641 }}</ref>

===Respiratory infections===

Most sinusitis infections are caused by [[virus]]es, for which amoxicillin and amoxicillin-clavulanate are ineffective,<ref name="AAAAIfive">{{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 }}</ref> and the small benefit gained by amoxicillin may be overridden by the adverse effects.<ref name="antibioticssinusitis">{{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 }} {{Retracted |doi=10.1002/14651858.cd000243.pub4}}</ref>

Amoxicillin is considered the first-line [[empirical treatment]] for most cases of uncomplicated bacterial sinusitis in children and adults when culture data is unavailable.<ref>{{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]]}}</ref><ref>{{cite Q|Q38897648}}</ref><ref>{{cite Q|Q104102440}}</ref> 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]].<ref>{{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) }}</ref> The [[World Health Organization]] (WHO) recommends amoxicillin as first-line treatment for pneumonia that is not "severe".<ref>{{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 }}</ref> Amoxicillin is used in post-exposure inhalation of [[anthrax]] to prevent disease progression and for prophylaxis.<ref name = Davisamox/>

===''H. pylori''===

It is effective as one part of a multi-drug regimen for 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.<ref>{{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 }}</ref>

===Lyme borreliosis===

Amoxicillin is effective for treatment of early cutaneous [[Lyme borreliosis]]; the effectiveness and safety of oral amoxicillin is neither better nor worse than common alternatively-used antibiotics.<ref>{{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 }}</ref>

===Odontogenic infections===

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 system]]s.<ref>{{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 }}</ref>

===Skin infections===

Amoxicillin is occasionally used for the treatment of skin infections,<ref name = Davisamox/> such as [[acne vulgaris]].<ref>{{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 }}</ref> It is often an effective treatment for cases of acne vulgaris that have responded poorly to other antibiotics, such as [[doxycycline]] and [[minocycline]].<ref>{{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 }}</ref>

===Infections in infants in resource-limited settings===

Amoxicillin is recommended by the World Health Organization for the treatment of [[infant]]s 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.<ref>{{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 }}</ref>

===Prevention of bacterial endocarditis===

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 bacteria]]l infections in those without [[spleen]]s, such as people with [[sickle-cell disease]], and for both the prevention and the treatment of [[anthrax]].<ref name=AHFS2015/> The United Kingdom recommends against its use for infectious endocarditis prophylaxis.<ref>{{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 }}</ref> These recommendations do not appear to have changed the rates of infection for infectious endocarditis.<ref>{{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 }}</ref>

===Combination treatment===

Amoxicillin is susceptible to degradation by [[beta-lactamase|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 [[Coamoxiclav|co-amoxiclav]].<ref>{{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}}</ref>

=== Spectrum of activity ===

It is a [[Antimicrobial spectrum|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.<ref>{{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}}</ref> Some ''[[Escherichia coli|E. coli]]'' and most clinical strains of ''[[Staphylococcus aureus]]'' have developed resistance to amoxicillin to varying degrees.<ref>{{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 }}</ref>

==Adverse effects==

[[Adverse drug reaction|Adverse effect]]s are similar to those for other [[β-lactam antibiotic]]s, including [[nausea]], vomiting, rashes, and antibiotic-associated [[colitis]]. Loose bowel movements (diarrhea) may also occur. Rarer adverse effects include mental changes, lightheadedness, insomnia, confusion, anxiety, sensitivity to lights and sounds, and unclear thinking. Immediate medical care is required upon the first signs of these adverse effects.<ref name="AHFS2015" />

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 fingertips and around 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]].<ref name="AHFS2015" />

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 failure|renal dysfunction]].<ref>{{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 }}</ref><ref>{{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}}</ref>

There is poor reporting of adverse effects of amoxicillin from clinical trials. For this reason, the severity and frequency of adverse effects from amoxicillin is probably higher than reported from clinical trials.<ref name="Common harms from amoxicillin: a sy"/>

===Nonallergic rash===

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]].<ref>{{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 }}</ref>

The rash is described as [[maculopapular]] or morbilliform ([[Measles|measles-like]]; therefore, in medical literature, it is called "amoxicillin-induced morbilliform rash".<ref>{{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}} }}</ref>). 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.<ref>{{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 }}</ref><ref>{{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 }}</ref>

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.<ref>{{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 }}</ref>

<gallery mode="packed" widths="360px" heights="220">

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.

== Interactions ==

Amoxicillin may interact with these drugs:

* [[Anticoagulants]] ([[dabigatran]], [[warfarin]]).<ref name="Davisamox" /><ref name="bnf57">British National Formulary 57 March 2009</ref><ref name=":0" /><ref name=":1">{{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 |language=en |doi=10.1007/978-981-15-3591-8_10 |isbn=978-981-15-3591-8 }}</ref>

* [[Methotrexate]] ([[chemotherapy]] and [[immunosuppressant]]).<ref name=":0" /><ref name=":1" />

* [[Typhoid vaccine|Typhoid]], [[Cholera vaccine|Cholera]] and [[BCG vaccine|BCG]] vaccines.<ref name=":0">{{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}}</ref><ref name=":1" />

* [[Probenecid]] reduces renal excretion and increases blood levels of amoxicillin.<ref name=":0" /><ref name=":1" />

* [[Oral contraceptives]] potentially become less effective.<ref>{{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 }}</ref>

* [[Allopurinol]] ([[gout]] treatment).<ref name=":0" /><ref name=":1" /><ref>{{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 |language=en |doi=10.1016/b978-1-4377-1160-8.10032-6 |isbn=978-1-4377-1160-8 }}</ref>

* [[Mycophenolic acid|Mycophenolate]] (immunosuppressant)<ref name=":1" />

<!-- {{Main|Beta-lactam antibiotic}} -->

==Pharmacology==

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.<ref>{{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 }}</ref> 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 [[Biological half-life|half-life]] of 3.7 hours in newborns and 1.4 hours in adults.<ref name = Davisamox/>

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''.<ref name = Davisamox/> As a derivative of [[ampicillin]], amoxicillin is a member of the [[penicillin]] family and, like penicillins, is a [[β-lactam antibiotic]].<ref name="Alcamo2003">{{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 }}</ref> It inhibits [[cross-link]]age 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]]).<ref>{{cite book|url=https://books.google.com/books?id=XiShDwAAQBAJ&pg=PA423| veditors = Sezer AD |publisher=[[Winchester Science Centre|INTECH]]|isbn=978-953-51-1628-8|title=Application of Nanotechnology in Drug Delivery|date=2016|page=423|access-date=24 July 2019}}</ref>

==History==

{{see also|Timeline of antibiotics}}

Amoxicillin was one of several [[semisynthesis|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.<ref>{{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}}</ref><ref>{{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}}</ref> It became available in 1972 and was the second [[aminopenicillin]] to reach the market (after [[ampicillin]] in 1961).<ref>{{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 }}</ref><ref name=Ravina>{{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}}</ref><ref>{{cite book | vauthors = Bruggink A |title=Synthesis of β-lactam antibiotics |publisher=Springer |year=2001 |page=17 |isbn=978-0-7923-7060-4}}</ref> [[Coamoxiclav|Co-amoxiclav]] became available in 1981.<ref name=Ravina/>

== Society and culture ==

===Economics===

Amoxicillin is relatively inexpensive.<ref>{{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 }}</ref> 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.<ref>{{cite web | url=https://www.talktomira.com/post/how-much-antibiotics-cost-without-insurance | title=How Much Do Antibiotics Cost Without Insurance in 2021?}}</ref>

=== Modes of delivery ===

Pharmaceutical manufacturers make amoxicillin in tri[[hydrate]] form, for oral use available as [[Capsule (pharmacy)|capsules]], regular, chewable and dispersible [[Tablet (pharmacy)|tablets]], syrup and [[pediatric]] [[Suspension (chemistry)|suspension]] for oral use, and as the sodium salt for [[intravenous]] administration.{{medcn|date=September 2022}}

An [[extended-release]] is available.<ref name="Moxatag FDA label" /><ref>{{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}}</ref> The intravenous form of amoxicillin is not sold in the United States.<ref>{{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 (imprint)|Saunders]]}}</ref> 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.<ref>{{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}}</ref>

Research with mice indicated successful delivery using [[intraperitoneally]] injected amoxicillin-bearing [[microparticles]].<ref>{{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 }}</ref>

===Names===

<!-- DO NOT ADD DRUG NAMES HERE. THERE ARE TOO MANY TO LIST IN WIKIPEDIA -->

"Amoxicillin" is the [[International Nonproprietary Name]] (INN), [[British Approved Name]] (BAN), and [[United States Adopted Name]] (USAN), while "amoxycillin" is the [[Australian Approved Name]] (AAN).{{cn|date=September 2022}}

Amoxicillin is one of the semisynthetic penicillins discovered by 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.<ref name=brands>{{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}}</ref>

<!-- DO NOT ADD DRUG NAMES HERE. THERE ARE TOO MANY TO LIST IN WIKIPEDIA -->

==Veterinary uses==

Amoxicillin is also sometimes used as an [[Antibiotic use in livestock|antibiotic for animals]]. The use of amoxicillin for animals intended for human consumption ([[chicken]]s, [[cattle]], and [[swine]] for example) has been approved.<ref name="Amoxicillin- FAO">{{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}}</ref>

* {{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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