Augmentin. What diseases does it treat?

Augmentin (amoxicillin–clavulanate) treats acute bacterial sinusitis, community-acquired pneumonia with likely beta-lactamase pathogens, uncomplicated urinary infections caused by susceptible E. coli/Klebsiella, and many skin and soft-tissue infections due to beta-lactamase–producing staphylococci and streptococci. Base the choice on local antibiogram data, clinical severity, and allergy history rather than empiric broadening without indication.

Use common adult regimens such as 500/125 mg every 8 hours or 875/125 mg every 12 hours. For children dose by weight, typically 25–45 mg/kg/day of the amoxicillin component divided every 8–12 hours; follow formulation-specific instructions. Typical durations: 5–7 days for many uncomplicated respiratory infections, and 7–14 days for complicated urinary or skin infections depending on clinical response and source control.

Amoxicillin with clavulanate restores activity against many beta-lactamase producers (Haemophilus influenzae, Moraxella catarrhalis, many E. coli and Klebsiella, methicillin-susceptible Staphylococcus aureus) but does not reliably cover MRSA, Pseudomonas, or some enterococci. Check culture and susceptibility results when available and de-escalate therapy to a narrower agent when appropriate.

Screen for immediate-type penicillin allergy before prescribing; a reported rash or mild intolerance may still permit use under clinician guidance, but angioedema or anaphylaxis contraindicates beta-lactams. Counsel patients on common adverse effects–gastrointestinal upset and diarrhea–and on signs that require prompt review (worsening fever, new rash, breathing difficulty, jaundice). Adjust dose or interval in renal impairment and consult local dosing guidelines for precise adjustments.

When to Prescribe Augmentin for Acute Bacterial Sinusitis: diagnostic criteria and recommended duration

Prescribe amoxicillin–clavulanate (Augmentin) only for patients who meet established diagnostic criteria for acute bacterial sinusitis: persistent symptoms ≥10 days without improvement, severe onset with fever ≥39°C plus purulent nasal discharge or facial pain for ≥3 consecutive days, or worsening symptoms after an initial improvement (double-sickening).

Diagnostic criteria

Use these objective triggers to start antibiotics rather than relying on purulent discharge alone: persistence for at least 10 days; high fever plus purulence or facial pain for 3 or more days; return or worsening of symptoms within 10 days after brief improvement. Consider point-of-care nasal endoscopy or sinus imaging only when diagnosis remains uncertain or complications are suspected (orbital signs, neurologic deficits).

Recommended dosing and duration

Select dose and duration based on severity, risk factors for resistance (recent β-lactam use, comorbidities, age >65), and clinical response. Reassess at 48–72 hours and stop or shorten therapy if symptoms clear; extend therapy if symptoms persist or worsen.

Population	Typical Augmentin regimen	Usual duration
Adults – mild to moderate	Amoxicillin–clavulanate 875/125 mg PO twice daily or 500/125 mg PO three times daily	5–7 days if marked improvement within 48–72 hours; extend to 10–14 days if inadequate response
Adults – high risk or severe disease	High‑dose amoxicillin–clavulanate 2000/125 mg (2 g/125 mg ER) PO twice daily	10–14 days, reassess at 48–72 hours for response
Children – standard risk	Amoxicillin component 45 mg/kg/day divided twice daily (total daily dose ≈45 mg/kg)	5–10 days: 10 days for children <6 years or severe presentation; 5–7 days acceptable for older children who improve quickly
Children – high risk or severe	High‑dose amoxicillin component 80–90 mg/kg/day divided twice daily (≈45 mg/kg per dose)`	10–14 days, with reassessment at 48–72 hours

If no clinical improvement within 48–72 hours on an appropriate Augmentin regimen, obtain culture (endoscopic or sinus aspirate when feasible), consider alternate pathogens or complications, and refer to ENT for further evaluation.

Augmentin dosing for pediatric otitis media: weight-based calculations and formulation selection

Use amoxicillin-clavulanate dosed by the amoxicillin component: high-dose 80–90 mg/kg/day (divided twice daily) for children at risk for resistant Streptococcus pneumoniae or with moderate–severe illness; standard dosing 40–50 mg/kg/day divided twice daily for uncomplicated cases.

• How to calculate: determine target mg/kg/day → divide by number of daily doses (usually 2) → multiply by child’s weight (kg). Example formula: per-dose mg = (target mg/kg/day ÷ 2) × weight (kg).
• High-dose example (90 mg/kg/day, BID): per-dose = 45 mg/kg.
  1. 10 kg → 450 mg per dose
  2. 15 kg → 675 mg per dose
  3. 20 kg → 900 mg per dose
• Convert mg to volume: volume (mL) = required mg per dose ÷ product concentration (mg amoxicillin per mL). Check the product label for exact mg/mL.

Practical volume examples using two common concentrations (illustrative only; verify your product):

• At 40 mg/mL: 450 mg → 11.25 mL; 675 mg → 16.9 mL; 900 mg → 22.5 mL.
• At 80 mg/mL: 450 mg → 5.6 mL; 675 mg → 8.4 mL; 900 mg → 11.25 mL.

Formulation selection and dosing strategy

• Prefer formulations with a lower clavulanate-to-amoxicillin ratio (e.g., ~14:1) to reduce gastrointestinal adverse effects while delivering the required amoxicillin dose.
• Choose higher-concentration suspensions or extended-spectrum (ES) formulations when they reduce dose volume to a practical, measurable amount (aim for a single-dose volume children can tolerate; many caregivers find ≤10 mL easier to give).
• Use twice-daily regimens when possible to improve adherence; ensure total daily amoxicillin meets the weight-based target.
• Select chewable tablets or scored tablets for older children who can reliably swallow, using weight-based mg to choose the tablet strength and number per dose.
• Always use the manufacturer’s concentration to calculate volume and supply a calibrated oral syringe for accurate measuring.

Duration and monitoring

• Duration by age:
  • <2 years – 10 days
  • 2–5 years – 7 days
  • ≥6 years – 5–7 days
• Reassess at 48–72 hours if symptoms worsen or fail to improve; adjust therapy based on clinical course and local resistance patterns.

Special considerations

• Children with severe vomiting or poor oral tolerance may need alternative routes or formulations; consider ENT or pediatric guidance for recurrent disease.
• For immediate-type penicillin allergy, select an allergy-appropriate alternative guided by susceptibility and local guidance.
• Adjust dosing in significant renal impairment per product labeling; routine renal dosing adjustments are uncommon in otherwise healthy children.

Augmentin in community-acquired pneumonia and COPD exacerbations: indications and monitoring parameters

Use amoxicillin–clavulanate for adult outpatients with community-acquired pneumonia (CAP) who have comorbidities (chronic heart, lung, liver, renal disease, diabetes, malignancy), recent antibiotic exposure, or suspected infection with beta‑lactamase–producing organisms; prescribe 875/125 mg PO twice daily or 500/125 mg PO three times daily for 5–7 days, extending to 7–10 days only if clinical improvement is delayed or complications arise.

For hospitalized patients with moderate–severe CAP consider IV amoxicillin–clavulanate 1.2 g every 8 hours as the beta‑lactam backbone; add a macrolide or doxycycline when atypical coverage is required, and escalate therapy if Gram‑negative or MRSA risk factors are present.

Offer Augmentin for acute bacterial exacerbations of COPD that meet clinical criteria for antibiotic therapy (increased dyspnea, sputum purulence and volume–Anthonisen type I, or type II with systemic features); typical adult dosing mirrors CAP choices (875/125 mg BID or 500/125 mg TID) for 5 days, with reassessment at 48–72 hours for clinical response.

Avoid amoxicillin–clavulanate in patients with immediate-type penicillin allergy or prior severe hepatic reaction to the drug; do not rely on Augmentin when Pseudomonas, ESBL organisms, or MRSA are suspected–choose targeted agents instead.

Obtain baseline renal function and liver enzymes before starting therapy in older adults, patients with hepatic or renal disease, or if therapy will exceed 7–14 days. Recheck ALT/AST and bilirubin if patient develops anorexia, right upper quadrant pain, dark urine, or jaundice. Monitor renal function during therapy in patients with fluctuating creatinine.

Watch for adverse effects: stop the drug and evaluate immediately for signs of hypersensitivity (rash, angioedema, respiratory compromise). Investigate persistent or severe diarrhea for Clostridioides difficile; discontinue antibiotic if C. difficile infection is suspected and manage accordingly. For courses longer than one week, consider a CBC to detect leukopenia or thrombocytopenia.

Adjust dosing in renal impairment by increasing dosing intervals or reducing dose per local product guidance; in patients on warfarin or other vitamin K antagonists, check INR within 2–3 days of starting and periodically thereafter due to interaction risk. Document clinical parameters (temperature, respiratory rate, oxygen requirement, sputum characteristics) at baseline and at 48–72 hours to guide duration and need for escalation or de‑escalation.

Use of Augmentin for urinary tract infections: culture-guided selection and scenarios favoring its use

Prefer amoxicillin–clavulanate for UTI when urine culture confirms a susceptible isolate or when specific clinical circumstances (pregnancy, polymicrobial catheter-associated infection, oral step-down after effective IV therapy) make it the best practical choice.

Obtain a urine culture before starting therapy in complicated UTI, recurrent infection, febrile UTI, pregnancy, or any patient recently exposed to antibiotics. Use the reported susceptibility to amoxicillin–clavulanate (not just amoxicillin); if the lab reports ESBL or high-level AmpC production, select an alternative. If local E. coli resistance to amoxicillin–clavulanate exceeds ~20% avoid empiric use.

Choose Augmentin for: 1) pregnant women with asymptomatic bacteriuria or cystitis when the isolate is susceptible (standard oral regimens achieve high urinary concentrations and are well tolerated in pregnancy); 2) catheter-associated or polymicrobial lower urinary tract infections where beta-lactamase–producing but non-ESBL Enterobacterales are isolated; 3) oral step-down after IV beta-lactam therapy for susceptible isolates and clear clinical improvement; 4) selected cases of recurrent UTI where first-line agents are contra‑indicated and susceptibility supports use.

Use typical adult oral dosing of 500/125 mg three times daily or 875/125 mg twice daily, adjusting duration by syndrome: lower urinary tract infection 5–7 days if chosen; pregnancy and persistent bacteriuria 7 days; acute pyelonephritis 10–14 days with switch to oral only after clinical stabilization and documented susceptibility; complicated UTI or urosepsis guided by clinical response, often 7–14 days. Reduce dosing frequency in severe renal impairment (CrCl <30 mL/min) per product labeling.

Interpret microbiology carefully: clavulanate restores activity against many plasmid-mediated beta-lactamases but not ESBLs or inducible AmpC enzymes. Confirm minimum inhibitory concentrations when available and consider repeat culture if symptoms persist despite therapy.

Monitor for adverse effects during treatment: expect gastrointestinal upset and risk of Clostridioides difficile; stop the drug and reassess if marked diarrhea or jaundice develops. Avoid in patients with documented penicillin anaphylaxis and prefer alternative agents when oral therapy is unlikely to reach the site of infection (severe pyelonephritis before IV therapy).

Practical approach: culture first for nontrivial UTI; if isolate is susceptible and clinical context fits one of the scenarios above, use amoxicillin–clavulanate at the doses and durations listed; otherwise select a guideline-recommended agent matched to the isolate and patient factors.

Treating skin and soft tissue infections with Augmentin: likely pathogens and thresholds for escalation

Use oral amoxicillin–clavulanate for mild-to-moderate nonpurulent cellulitis and for bite-associated wounds; perform source control (incision and drainage, debridement) first for any purulent focus and obtain cultures before giving antibiotics when possible.

Expect coverage gaps and strengths: amoxicillin–clavulanate reliably covers beta-hemolytic streptococci (Streptococcus pyogenes and other streptococci), methicillin-susceptible Staphylococcus aureus (MSSA), Pasteurella multocida (cat/dog bites), Eikenella corrodens (human bites), and mixed oral anaerobes (Bacteroides/Prevotella). It does not cover MRSA or many Pseudomonas strains; enteric Gram-negatives can be present in puncture wounds and diabetic foot infections.

When to escalate to MRSA-active therapy: add or switch to MRSA-targeted agents if purulence with high local MRSA prevalence, prior MRSA infection/colonization, severe purulent SSTI unresponsive to drainage alone, or systemic signs with suspected MRSA. Outpatient MRSA options include trimethoprim–sulfamethoxazole or doxycycline; hospital options include vancomycin, daptomycin or linezolid depending on severity and renal function.

When to escalate to IV and broader-spectrum inpatient treatment: choose IV therapy and admit for any of the following: systemic inflammatory response (fever >38°C, HR>90, RR>20, WBC >12,000 or <4,000), hypotension or lactate >2 mmol/L, rapidly expanding erythema or progression despite 48–72 hours of appropriate oral therapy, signs of deep infection (severe pain out of proportion, bullae, crepitus, anesthesia), suspected necrotizing infection, immunocompromise, limb-threatening infection, or suspected osteomyelitis/diabetic foot with ischemia. Start IV beta-lactam/beta-lactamase combinations (IV ampicillin–sulbactam or IV amoxicillin–clavulanate where available) for beta-lactam–susceptible pathogens and add MRSA coverage when indicated.

Bite wounds: give amoxicillin–clavulanate promptly for most dog and cat bites and for human bites to cover Pasteurella and Eikenella plus anaerobes; admit and start IV therapy if deep penetration, neurovascular compromise, delayed presentation (>24–48 hours with spreading infection), systemic signs, or if the patient is immunocompromised.

Diabetic foot and puncture wounds: use amoxicillin–clavulanate for mild, superficial infections without risk factors for Pseudomonas; escalate to broader gram-negative and anaerobic coverage (and consider surgical consultation and bone imaging) when probe-to-bone, ischemia, failure of oral therapy, or prior exposure to water/contaminated environments suggests Pseudomonas or mixed Gram-negative infection.

Microbiology and cultures: obtain wound cultures for purulent drainage, recurrent infections, treatment failure, severe infections or immunosuppressed patients; draw blood cultures if febrile or systemically ill. Tailor therapy to culture results: de-escalate to narrow-spectrum agents when susceptibilities permit.

Practical dosing and duration guidance: typical adult oral regimens include 875/125 mg twice daily or 500/125 mg three times daily for 5–10 days for uncomplicated cellulitis after adequate source control; adjust duration upward for delayed clinical response, osteomyelitis, or deeper infection per specialist guidance. Reassess at 48–72 hours; change therapy if no clinical improvement or if culture results demand alternative coverage.

Adjusting Augmentin for renal impairment and checking drug interactions and allergy history

Reduce dose or extend dosing interval based on measured creatinine clearance (CrCl): for CrCl ≥30 mL/min use standard Augmentin regimens; for CrCl 10–30 mL/min halve the total daily dose or give the usual single dose at double the interval (for example, change 500/125 mg every 8 hours to 500/125 mg every 12–24 hours, or 875/125 mg every 12 hours to 875/125 mg every 24 hours); for CrCl <10 mL/min or anuric patients give a single reduced daily dose and administer intravenous doses after hemodialysis. For IV amoxicillin/clavulanate (commonly 1.2 g every 8 hours), consider 1.2 g every 12 hours for CrCl 10–30 mL/min and every 24 hours for CrCl <10 mL/min; give the loading dose after dialysis and subsequent doses post-dialysis on dialysis days.

Calculate renal function with Cockcroft–Gault for dosing decisions in adults; recalculate during therapy if serum creatinine changes or if the patient receives nephrotoxic drugs (aminoglycosides, vancomycin, high‑dose loop diuretics, IV contrast). For elderly or low‑muscle‑mass patients consider measured urine collection or eGFR plus clinical judgment when Cockcroft–Gault may be unreliable.

Screen actively for interacting drugs before prescribing: monitor INR frequently and adjust warfarin dose while on, because amoxicillin/clavulanate can raise INR; expect increased methotrexate toxicity due to reduced renal clearance–avoid combination or monitor levels and toxicity closely; probenecid decreases renal tubular secretion of amoxicillin and raises plasma concentrations–if used together consider dose reduction or closer monitoring for adverse effects; coadministration with valproate can lower valproate concentrations and precipitate seizures–check levels and consider alternative antibiotics or anticonvulsant adjustments; allopurinol combined with penicillins increases the risk of rash–watch for dermatologic reactions.

Confirm allergy phenotype before use: any history of immediate IgE‑mediated reactions to penicillin (anaphylaxis, angioedema, bronchospasm, urticaria) contraindicates Augmentin–select a non‑beta‑lactam alternative and refer to allergy/immunology for testing. For remote or vague histories, perform penicillin skin testing when available; a negative skin test permits safe administration. For delayed, non‑severe maculopapular rashes consider a graded oral challenge under supervision rather than automatic exclusion. If prior Augmentin or clavulanate exposure produced cholestatic hepatitis, avoid rechallenge permanently.

Establish baseline and on‑therapy monitoring: obtain serum creatinine and calculate CrCl at baseline and after 48–72 hours in patients with risk factors for renal decline; check LFTs before therapy when treatment will exceed 14 days or when baseline liver disease exists and repeat if jaundice, dark urine, or elevated transaminases occur; monitor INR in patients on warfarin within 48–72 hours of starting antibiotic and at intervals thereafter; assess for rash, severe diarrhea, or signs of superinfection and stop the drug if severe hypersensitivity or clinically significant hepatic injury develops.

Practical prescriber checklist: calculate CrCl (Cockcroft–Gault), choose adjusted dose and interval, review current medications for warfarin/methotrexate/valproate/probenecid/allopurinol interactions, document allergy type and date, arrange penicillin skin testing or allergy referral when history is unclear and therapy is necessary, and plan specific laboratory monitoring (renal function, LFTs, INR, drug levels where applicable) with clear timing next to the prescription.