- Drugs List
- Therapeutic Indications
- Precautions and Warnings
- Pregnancy and Lactation
- Side Effects
Oral formulations containing amoxicillin
Antibiotic sensitive infections
Dental infections - acute
Endocarditis - prophylaxis
Eradication of Helicobacter pylori (with other drugs)
Treatment and prophylaxis of anthrax
Urinary tract infection
Amoxicillin is a broad spectrum aminopenicillin antibiotic indicated for the treatment of commonly occurring bacterial infections. Infections include:
Upper respiratory tract infections: sinusitis
Lower respiratory tract infections: acute and chronic bronchitis, chronic bronchial sepsis, lobar and bronchopneumonia
Ear infections: otitis media
Genitourinary infections: cystitis, urethritis, pyelonephritis, bacteriuria during pregnancy, gonorrhoea, gynaecological infections including puerperal sepsis and septic abortion, urinary tract infection
Gastrointestinal infections: typhoid fever, paratyphoid fever, Helicobacter pylori eradication in peptic (duodenal and gastric) ulcer disease
Bone and joint infection: osteomyelitis
Skin and soft tissue infections
Other: septicaemia, intra-abdominal sepsis, peritonitis, bacterial endocarditis, dental abscess as adjunct to surgery
Amoxicillin is also indicated for the prophylaxis of endocarditis
Not all brands are licensed for all indications.
Prophylaxis of pneumococcal infection (post-splenectomy/in sickle cell dis)
Prevention of pneumococcal infection in asplenia or in patients with sickle-cell disease if cover also needed for H. influenzae (children only)
Acute bacterial sinusitis: 250mg to 500mg every 8 hours or 750mg to 1g every 12 hours. Increase to 750mg to 1g every 8 hours in severe infections.
Asymptomatic bacteriuria in pregnancy: 250mg to 500mg every 8 hours or 750mg to 1g every 12 hours. Increase to 750mg to 1g every 8 hours in severe infections.
Acute pyelonephritis: 250mg to 500mg every 8 hours or 750mg to 1g every 12 hours. Increase to 750mg to 1g every 8 hours in severe infections.
Dental abscess with spreading cellulitis: 250mg to 500mg every 8 hours or 750mg to 1g every 12 hours. Increase to 750mg to 1g every 8 hours in severe infections.
Acute cystitis: 250mg to 500mg every 8 hours or 750mg to 1g every 12 hours. Increase to 750mg to 1g every 8 hours in severe infections. Alternatively, give 3g twice daily for one day.
Acute otitis media: 500mg every 8 hours or 750mg to 1g every 12 hours. Increase to 750mg to 1g every 8 hours for ten days in severe infections.
Acute streptococcal tonsillitis and pharyngitis: 500mg every 8 hours or 750mg to 1g every 12 hours. Increase to 750mg to 1g every 8 hours for ten days in severe infections.
Acute exacerbations of chronic bronchitis: 500mg every 8 hours or 750mg to 1g every 12 hours. Increase to 750mg to 1g every 8 hours for ten days in severe infections.
Community acquired pneumonia: 500mg to 1g every 8 hours.
Prosthetic joint infections: 500mg to 1g every 8 hours.
Typhoid and paratyphoid fever: 500mg to 2g every 8 hours.
Prophylaxis of endocarditis: 2g as a single dose 30 to 60 minutes before procedure. Helicobacter pylori eradication: 750mg to 1g twice daily in combination with a proton pump inhibitor and another antibiotic for 7 days.
Prophylaxis and treatment of anthrax: 500mg every 8 hours.
Dental abscess: 3g followed by another 3g 8 hours later.
Helicobacter pylori eradication: 500mg every 8 hours.
Early stage: 500mg to 1g every 8 hours, up to a maximum of 4g, daily in divided doses for 10 to 21 days.
Late stage (systemic involvement): 500mg to 2g every 8 hours, up to a maximum of 6g, daily in divided doses for 10 to 30 days.
Children weighing 40kg or more
(See Dosage; Adult)
Children weighing less than 40kg
Acute bacterial sinusitis: 20mg/kg to 90mg/kg daily in divided doses.
Acute otitis media: 20mg/kg to 90mg/kg daily in divided doses.
Community acquired pneumonia: 20mg/kg to 90mg/kg daily in divided doses.
Acute cystitis: 20mg/kg to 90mg/kg daily in divided doses.
Acute pyelonephritis: 20mg/kg to 90mg/kg daily in divided doses.
Dental abscess with spreading cellulitis: 20mg/kg to 90mg/kg daily in divided doses.
Acute streptococcal tonsillitis and pharyngitis: 40mg/kg to 90mg/kg daily in divided doses.
Typhoid and paratyphoid fever: 100mg/kg daily in three divided doses.
Prophylaxis of endocarditis: 50mg/kg as a single dose 30 to 60 minutes before procedure.
Early stage: 25mg/kg to 50mg/kg daily in three divided doses for 10 to 21 days. Late stage (systemic involvement): 100mg/kg in three divided doses for 10 to 30 days.
For general infections, the following alternative dosing schedules may be suitable:
Children aged 12 to 18 years: 500mg three times daily. Increase up to 1g three times daily.
Children aged 5 to 12 years: 500mg three times daily. Increase up to 30mg/kg (maximum 1g) three times daily.
Children aged 1 to 5 years: 250mg three times daily. Increase up to 30mg/kg three times daily.
Children aged 1 month to 1 year: 125mg three times daily. Increase up to 30mg/kg three times daily.
Children aged 5 to 18 years: 500mg three times daily for 21 days (28 days in Lyme arthritis).
Children aged 1 to 5 years: 250mg three times daily. Increase up to 30mg/kg three times daily. Continue for 2 to 4 weeks.
Children aged 1 month to 1 year: 125mg three times daily. Increase up to 30mg/kg three times daily. Continue for 2 to 4 weeks.
Prophylaxis and treatment of anthrax
Children weighing 20kg or more: 500mg three times a day.
Children weighing less than 20kg: 80?mg/kg daily in three divided doses.
Prevention of pneumococcal infection in asplenia or in patients with sickle cell disease
Children aged 12 to 18 years: 500mg twice daily.
Children aged 5 to 12 years: 250mg twice daily.
Children aged 1 month to 4 year: 125mg twice daily.
Neonates aged 7 to 28 days
30mg/kg (maximum 125mg) three times daily.
Patients with Renal Impairment
The total daily dosage should be reduced depending on the level of renal impairment, as there may be a delay in the excretion of the antibiotic. The following dosage adjustments are recommended:
Adults, elderly and children 40kg and above in weight
Glomerular filtration rate more than 30ml/minute: No adjustment necessary.
Glomerular filtration rate of 10 to 30ml/minute: Maximum 500mg twice daily.
Glomerular filtration rate less than 10ml/minute: Maximum 500mg daily
Children under 40kg in weight
Glomerular filtration rate of more than 30ml/minute: No adjustment necessary
Glomerular filtration rate of 10 to 30ml/minute: 15mg/kg given twice daily (maximum 500mg twice daily)
Glomerular filtration rate of less than 10ml/minute: 15mg/kg given as a single daily dose (maximum 500mg)
In patients receiving haemodialysis
Amoxicillin may be removed from the circulation by haemodialysis.
Adults, elderly and children over 40kg in weight
500mg every 24 hours
Prior to haemodialysis, one additional dose of 500mg should be administered. Another dose of 500mg should be administered after haemodialysis, in order to restore circulating drug levels.
Children under 40kg in weight
15mg/kg given as a single daily dose. The maximum dose is 500mg. Prior to haemodialysis one additional dose of 15mg/kg should be administered. Another dose of 15mg/kg should be administered after haemodialysis, in order to restore circulating drug levels.
In patients receiving peritoneal dialysis
The maximum dose is 500mg per day.
Hereditary fructose intolerance
Precautions and Warnings
Renal impairment - glomerular filtration rate below 30ml/minute
Renal impairment in children - creatinine clearance < 30ml/minute/1.73m sq
Reduce dose in patients with creatinine clearance below 30ml/min
Some formulations contain aspartame - caution in phenylketonuria
Advise ability to drive/operate machinery may be affected by side effects
Before initiating therapy enquire about previous hypersensitivity reactions
Consult national/regional policy on the use of anti-infectives
Not all available brands are licensed for all indications
Presentations with sorbitol unsuitable in hereditary fructose intolerance
Some presentations may contain benzyl alcohol
Maintain hydration and urinary output
Monitor haematological status during prolonged and high dose therapy
Monitor hepatic function on long term therapy
Monitor patency of urinary catheters regularly, precipitation may occur
Monitor patients receiving concurrent anticoagulants
Monitor renal function during prolonged/high dose therapy
Erythematous rash common in glandular fever, CMV inf, lymphocytic leukaemia
Prolonged use may result in superinfection with non-susceptible organisms
May affect results of some laboratory tests
Discontinue if drug-related rash or other hypersensitivity reactions occur
Amoxicillin should be given with caution to patients with a history of allergy, especially to drugs. Desensitisation may be required if treatment is essential.
Urticarial reactions are typical of penicillin hypersensitivity while erythematous maculopapular eruptions are characteristic of amoxicillin and often appear more than 7 days after starting treatment. Erythematous rashes are common in patients with infectious mononucleosis (glandular fever), cytomegalovirus, or acute or chronic lymphocytic leukaemia.
Care should be taken with the use of amoxicillin in premature children and during the neonatal period and the renal, hepatic and haematological functions should be monitored.
Crystalluria has been observed rarely in patients with reduced urine output, predominantly with parenteral therapy. At high doses adequate fluid intake and urinary output must be maintained in order to reduce the possibility of crystalluria. The presence of high concentrations of amoxicillin in the urine may cause precipitation of the product in a urinary catheter. Therefore, catheters should be visually inspected at intervals during treatment.
In children with a urinary tract infection, the need for further clinical investigation should be considered.
The Faculty of Sexual and Reproductive Health has issued revised guidance concerning additional contraceptive cover when antibiotics are prescribed to patients taking combined oral contraceptives in January 2011. With the exception of the enzyme-inducing antibiotics rifampicin and rifabutin, it is no longer necessary to advise the patient to take additional contraceptive precautions while also taking an antibiotic.
Advise the patient that if vomiting occurs, she should follow the guidance for the oral contraceptive in respect of additional doses or contraceptive precautions.
Not all brands are licensed for all indications and some brands contain sorbitol. Sorbitol containing formulations should not be taken by patients with hereditary fructose intolerance. Caution in use in patients with glucose-galactose malabsorption syndrome.
Pregnancy and Lactation
There is no evidence that amoxicillin has a teratogenic effect, and its suitability for use during pregnancy has been well documented in clinical studies. The Collaborative Perinatal Project monitored 50,282 mother-child pairs, 3546 of whom had first trimester exposures to penicillin derivatives. For use at any time during pregnancy, 7171 exposures were recorded, in neither group was evidence found to suggest a relationship to large categories of major or minor malformations or to individual defects.
The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).
Amoxicillin may be given during breastfeeding
With the exception of possible sensitisation associated with the excretion of trace amounts of amoxicillin in breast milk, there are no known detrimental effects for the breast-fed infant. Studies have shown that less than 0.95% of the maternal dose is excreted into human milk.
Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1
Acute generalised exanthematous pustulosis
Drug rash with eosinophilia and systemic symptoms (DRESS)
Increase in serum ALT/AST
Overgrowth by non-susceptible organisms
Prothrombin time increased
Serum sickness-like reactions
Soft or liquid stools
Superficial tooth discolouration
Toxic epidermal necrolysis
Effects on Laboratory Tests
When testing for the presence of glucose in urine during amoxicillin treatment, enzymatic glucose oxidase methods should be used. Due to high urinary concentrations of amoxicillin, false readings are common with chemical methods.
It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.
The following number will direct the caller to the relevant local centre (0844) 892 0111
Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).
Last Full Review Date: October 2013
Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 2nd edition (2007) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.
Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 9th edition (2011) ed. Briggs, G., Freeman, R. and Yaffe, S. Lippincott Williams & Wilkins, Philadelphia.
Martindale: The Complete Drug Reference, 37th edition (2011) ed. Sweetman, S. Pharmaceutical Press, London.
Medications and Mothers' Milk, 14th Edition (2010) Hale, T. Hale Publishing, Amarillo, Texas.
Summary of Product Characteristics: Amoxicillin 125 mg/5 ml suspension. Sandoz Ltd. Revised June 2015.
Summary of Product Characteristics: Amoxicillin 500 mg/5 ml suspension. Brown & Burk UK Ltd. Revised January 2020.
Summary of Product Characteristics: Amoxil Capsules 250mg. GlaxoSmithKline UK. Revised March 2017.
Summary of Product Characteristics: Amoxil Capsules 500mg. GlaxoSmithKline UK. Revised March 2017.
Summary of Product Characteristics: Amoxicillin Dispersible Tablets 1000mg. RX Pharma Revised May 2020.
Summary of Product Characteristics: Amoxil Paediatric Suspension. GlaxoSmithKline UK. Revised September 2013.
Summary of Product Characteristics: Amoxil 3g Sachet. GlaxoSmithKline UK. Revised January 2012.
Faculty of Sexual and Reproductive Healthcare
Last accessed 7 October 2013
NICE - Evidence Services
Available at: www.nice.org.uk
Last accessed: 19 April 2021
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