Amoxicillin-Clavulanate

USE IF: Suspected β-lactamase–producing organisms; bite wounds (human/animal); acute bacterial rhinosinusitis (ABRS), acute otitis media (AOM), and mild–moderate community-acquired pneumonia (CAP) in the outpatient setting; skin and soft tissue infection (SSTI); dental infections. AVOID IF: History of penicillin anaphylaxis; history of amoxicillin-clavulanate–associated cholestatic jaundice or hepatitis; creatinine clearance <30 mL/min (avoid 875/125 mg and extended-release / high-clavulanate regimens per product labeling). Amoxicillin-clavulanate is a broad-spectrum oral β-lactam combination for polymicrobial and β-lactamase–producing pathogens, with anaerobic coverage useful in selected dental, bite, and SSTI syndromes. Clavulanate adds diarrhea risk and hepatotoxicity signal versus amoxicillin alone—choose formulation and duration deliberately. Clavulanate inhibits β-lactamases but increases GI and hepatotoxicity risk — use the lowest effective clavulanate exposure.

• Primary: ABRS, AOM, CAP (mild–moderate), bite wounds, SSTI, dental infections
• Secondary: COPD exacerbation, UTI, diabetic foot infection, PID
• Other: SIBO, H. pylori regimens, Lyme disease (alternative regimens per guideline)

• History of IgE-mediated penicillin hypersensitivity (e.g., anaphylaxis)
• Do not use: History of amoxicillin-clavulanate–associated cholestatic jaundice or hepatitis
• Adjust dosing in renal impairment; avoid high-dose formulations when CrCl <30 mL/min
• Use caution: Underlying liver disease or alcohol-related liver risk
• Use caution: Anticoagulants (warfarin), methotrexate, probenecid, allopurinol
• Use caution: Frail elderly and polypharmacy

• Warfarin → ↑ INR
• Methotrexate → ↓ clearance
• Probenecid → ↑ amoxicillin levels
• Allopurinol → ↑ rash risk

Give with food to reduce GI intolerance. PO tablets and suspension: take with meals as tolerated. IV: infuse over 30–40 minutes per institutional guidance. Avoid incompatible dextrose diluents where stability is limited; reconstituted solutions are stable only for a short interval—prepare immediately before use and discard per policy.

• Labs: LFTs when baseline risk or prolonged/repeated therapy; renal function for dose adjustment; INR if on warfarin; CBC if methotrexate co-therapy or prolonged treatment
• Clinical: diarrhea suggesting C. difficile; rash or anaphylaxis; jaundice or pruritus suggesting cholestasis
• No clinical improvement at 48–72h → reassess diagnosis, resistance, source control, and drug interactions (DO NOT continue blindly)
• If targets not met after reassessment of dose, organ function, and interactions → escalate per protocol (DO NOT continue blindly)

Oral bioavailability roughly 70–90% for many formulations; volume of distribution near 0.4 L/kg; protein binding relatively low. Elimination is predominantly renal for amoxicillin with hepatic and renal contribution for clavulanate. Dialyzable components—adjust timing around dialysis per reference.

Amoxicillin inhibits penicillin-binding proteins and disrupts peptidoglycan synthesis, leading to cell wall lysis in susceptible organisms. Clavulanate irreversibly inhibits many bacterial β-lactamases, protecting amoxicillin from enzymatic inactivation.