Amoxicillin
General information
A penicillin antibiotic. Do NOT use if patient is allergic to penicillin.
Formulary antimicrobial: Use in accordance with Trust guidelines
AWaRe antibiotic classification: 'Access'. Use as per guidelines.
Standard dose
|
Oral amoxicillin |
Intravenous amoxicillin |
|
500mg - 1g TDS |
1g TDS* |
*2g 4-hourly can be used for listeria meningitis and infective endocarditis on the advice of Micro/ID.
Obesity
Dosing for penicillins should be at the upper end of recommended ranges, particularly for morbidly obese patient with severe infections, considering patient’s renal function.
Renal and hepatic impairment
Renal impairment
|
eGFR (mL/min/1.73m2) |
amoxicillin dose |
|
10 or more |
Dose as in normal renal function |
|
Less than 10 |
250mg–1g every 8 hours. Maximum 6g per day in endocarditis |
|
HD/HDF/High Flux/PD |
Dose as in eGFR less than 10ml/min/1.73m2. HD/HDF/High Flux: Dialysed; give after dialysis |
Hepatic impairment
No dose adjustment required. Hepatic function to be monitored regularly.
Notable interactions
Methotrexate: Amoxicillin can reduce excretion of methotrexate (increased risk of toxicity).
Vitamin K antagonists: Appropriate monitoring should be undertaken. It would be prudent to monitor coagulation status within 3 days of starting or stopping a penicillin.
This is not a complete list. Please see the BNF, Summary of Product Characteristics or speak to a pharmacist.
Pregnancy and breastfeeding
Pregnancy
Safe, human data suggests low risk
Breastfeeding
Safe, trace amounts in milk. Monitor infant for gastro-intestinal disturbances and oral candida infection, especially if used for prolonged periods or in high doses, although these effects are unlikely to occur. There is also a theoretical risk of hypersensitivity.
Additional information
Amoxicillin 1g contains 76mg of sodium per vial, equivalent to 3.8% of the WHO recommended maximum daily intake of sodium for an adult.
References
- Amoxicillin 500 mg Capsules BP [online]. Manufacturer - Sigma Pharmaceuticals PLC – last updated: 2023 June 30. Accessed via: www.emc.medicines.org.uk [Accessed 2023 Aug 24].
- Amoxicillin 1g Powder for Solution for Injection [online]. Manufacturer - Bowmed Ibisqus Limited – last updated: 2023 July 24. Accessed via: www.emc.medicines.org.uk [Accessed 2023 Aug 24].
- The Renal Drug Database. Amoxicillin - last updated: 2023 Mar 6. Accessed via: https://renaldrugdatabase.com [Accessed 2023 Aug 21].
- Habib G, et al. 2015 ESC guidelines for the management of infective endocarditis: the task force for the management of infective endocarditis of the European Society of Cardiology (ESC) endorsed by: European Association for Cardio-Thoracic Surgery (EACTS), the European Association of Nuclear Medicine (EANM). European heart journal. 2015 Nov 21;36(44):3075-128.
- UK Medicines Information. How should antibiotics be doses in obesity – last updated 2017 Mar 1. Accessed via: https://www.gloshospitals.nhs.uk/media/documents/Obese_Dosing_2016_update.pdf [Accessed September 2023].
- Specialist Pharmacy Service – Lactation Safety Information: Amoxicillin – last updated 2021 Oct 11. Accessed via: https://www.sps.nhs.uk/medicines [Accessed 2023 Aug 21].
- Briggs GG, Freeman RK, Towers CV, Forinash AB. Briggs Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk [online]. Lippincott Williams & Wilkins; 2021 Feb 18. Accessed via https://online.lexi.com [Accessed 2022 Nov 23].
- UK Teratology Information Service - USE OF PENICILLINS IN PREGNANCY – last updated 2019 Jan. Accessed via: https://uktis.org/ [Accessed 2023 Aug 21]