Amoxicillin-Clavulanate Dose Calculator
India · Co-amoxiclav · Augmentin · Moxikind-CV · Clavam · RTI · UTI · Skin · Dental · Paediatric 4:1 and 7:1 ratio explained
Amoxicillin-Clavulanate Dose Calculator
⚠️ Penicillin allergy — contraindicated
⚠️ Cholestatic jaundice — more common than plain amoxicillin (clavulanate effect)
⚠️ Diarrhoea common — clavulanate disrupts gut flora
⚠️ Limit clavulanate to 125mg/dose to reduce GI effects — key reason for 7:1 (875/125) formulation
⚠️ Rash in EBV (glandular fever) — check monospot before prescribing
✅ Reduce dose in renal impairment (CrCl <30)
Co-amoxiclav — Clinical Guide India
Amoxicillin-clavulanate (co-amoxiclav, Augmentin, Moxikind-CV, Clavam) is the most widely prescribed oral antibiotic combination in India for respiratory tract infections, urinary tract infections, skin infections, and animal bite prophylaxis. Clavulanate is a beta-lactamase inhibitor — it has no intrinsic antibacterial activity but protects amoxicillin from destruction by bacterial beta-lactamases, extending its spectrum to include beta-lactamase-producing organisms such as Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus (non-MRSA), Klebsiella, and anaerobes. The result is a significantly broader spectrum than plain amoxicillin.
Understanding the ratio — why it matters for dosing
Co-amoxiclav formulations are described by the ratio of amoxicillin to clavulanate. The Indian market has two main ratios: 4:1 (e.g. 625mg tablet = 500mg amoxicillin + 125mg clavulanate; 228.5mg/5ml suspension = 200mg amox + 28.5mg clav per 5ml) and 7:1 (e.g. 1000mg tablet = 875mg amoxicillin + 125mg clavulanate; 457mg/5ml suspension = 400mg amox + 57mg clav per 5ml). The key principle is that clavulanate causes most of the GI side effects (diarrhoea, nausea) — keeping clavulanate capped at 125mg per dose (using the 7:1 formulation) allows a higher amoxicillin dose while minimising GI intolerance. For children, dose calculations are always based on the amoxicillin component.
When to use co-amoxiclav vs plain amoxicillin
Plain amoxicillin is the correct first-line antibiotic for most community-acquired infections where the organism is likely susceptible. Co-amoxiclav is appropriate when: beta-lactamase-producing organisms are likely (second episode within 3 months, prior antibiotic use, failed plain amoxicillin, clinical severity), for animal bites (polymicrobial including Pasteurella), dental infections with suspected anaerobic component, and when clinical failure on plain amoxicillin has occurred. Over-prescribing co-amoxiclav over plain amoxicillin is a major driver of antimicrobial resistance in India and adds unnecessary cost and GI side effects.