Beta-lactam antibiotic

Amoxicillin (Otitis Media / Sinusitis)

Brand names: Amoxil

Used in: Sepsis Pneumonia COPD Urinary Tract Infection

Amoxicillin is a broad-spectrum penicillin used for respiratory, ENT, urinary and other infections, and within Helicobacter pylori eradication.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

Adults and Pediatric Patients greater than 40 kg: 500 or 875 mg every 12 hours or 250 or 500 mg every 8 hours, based on the amoxicillin component. ( 2.2 , 2.3 ) Pediatric patients aged 12 weeks (3 months) and older: 25 to 45 mg/kg/day every 12 hours or 20 to 40 mg/kg/day every 8 hours, up to the adult dose. ( 2.3 ) Neonates and infants less than 12 weeks of age: 30 mg/kg/day divided every 12 hours, based on the amoxicillin component. Use of the 125 mg/5 mL oral suspension is recommended. ( 2.3 ) 2.1 Important Administration Instructions Amoxicillin and Clavulanate Potassium may be taken without regard to meals; however, absorption of clavulanate potassium is enhanced when Amoxicillin and …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2024-04-30. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Clinical monograph

How it works

A beta-lactam that inhibits bacterial cell-wall synthesis by binding penicillin-binding proteins.

Prescribing in practice

Contraindicated in penicillin allergy; it commonly causes a non-allergic rash in glandular fever, so avoid it empirically there.
Many respiratory/ENT infections are viral or self-limiting — prescribe per local guidance and consider delayed prescribing.
Reduce the dose in significant renal impairment.

Monitoring

Short courses need no routine monitoring; review response and adverse effects.

Counselling the patient

Complete the prescribed course.
Report a rash, swelling or difficulty breathing (possible allergy).
Report severe or prolonged diarrhoea.

Evidence & guidelines

First-line for many bacterial respiratory/ENT infections per NICE/PHE antimicrobial guidance, within antibiotic-stewardship principles.

Reference: NICE NG98 AOM; PHE AOM Guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways