Comprehensive Guide to Amoxicillin-Clavulanate: Uses, Dosage, Side Effects, and More
What is Amoxicillin-Clavulanate?
Overview of Amoxicillin-Clavulanate
Generic Name: Amoxicillin-Clavulanate
Brand Name: Augmentin, generics
Drug Group: Penicillin antibiotic/Beta-lactamase inhibitor
Commonly Used For
- Treat respiratory tract infections.
- Manage skin and soft tissue infections.
- Address sinusitis and otitis media.
Key Characteristics
Form: Oral tablets (250 mg/125 mg, 500 mg/125 mg, 875 mg/125 mg), chewable tablets (125 mg/31.25 mg, 250 mg/62.5 mg), oral suspension (125 mg/31.25 mg/5 mL, 250 mg/62.5 mg/5 mL), IV injection (500 mg/100 mg, 1 g/200 mg) (detailed in Dosage section).
Mechanism: Amoxicillin inhibits bacterial cell wall synthesis; clavulanate prevents beta-lactamase degradation.
Approval: FDA-approved (1984 for Augmentin) and EMA-approved for bacterial infections.
Indications and Uses of Amoxicillin-Clavulanate
Amoxicillin-Clavulanate is indicated for a wide array of bacterial infections, leveraging its broad-spectrum activity:
Respiratory Tract Infections:
Treats acute bacterial exacerbations of chronic bronchitis, targeting Haemophilus influenzae and Moraxella catarrhalis, reducing symptom duration.
Manages community-acquired pneumonia, effective against Streptococcus pneumoniae and atypical pathogens, often as first-line therapy.
Ear, Nose, and Throat Infections:
Addresses acute otitis media in children, combating Streptococcus pyogenes and beta-lactamase-producing H. influenzae, with rapid symptom relief.
Treats sinusitis, including acute bacterial rhinosinusitis, reducing inflammation and bacterial load in maxillary sinuses.
Skin and Soft Tissue Infections:
Manages cellulitis and animal bites, targeting Staphylococcus aureus and Pasteurella multocida, preventing abscess formation.
Treats diabetic foot infections, addressing polymicrobial flora, often in combination with surgical care.
Urinary Tract Infections (UTIs):
Treats uncomplicated UTIs caused by Escherichia coli and Klebsiella pneumoniae, with clavulanate overcoming resistant strains.
Off-Label Uses:
Includes management of dental abscesses to drain infection and promote healing, treatment of pelvic inflammatory disease (PID) with Chlamydia trachomatis, and adjunctive therapy in aspiration pneumonia, supported by clinical guidelines and studies.
Prophylaxis in high-risk dental procedures for patients with prosthetic joints, under specialist oversight.
Treatment of chronic bacterial prostatitis, targeting resistant Enterococcus faecalis.
Intra-Abdominal Infections:
Manages complicated intra-abdominal infections (e.g., appendicitis), effective against anaerobes like Bacteroides fragilis.
H. pylori Eradication:
Used in triple therapy with a proton pump inhibitor and metronidazole to eradicate Helicobacter pylori in peptic ulcer disease.
Dosage of Amoxicillin-Clavulanate
Dosage for Adults
Respiratory Tract Infections (Oral): 500 mg/125 mg every 12 hours or 875 mg/125 mg every 12 hours for 7–10 days.
Sinusitis (Oral): 875 mg/125 mg every 12 hours or 500 mg/125 mg every 8 hours for 10–14 days.
Skin and Soft Tissue Infections (Oral): 500 mg/125 mg every 12 hours or 875 mg/125 mg every 12 hours for 7–14 days.
Urinary Tract Infections (Oral): 500 mg/125 mg every 12 hours for 7 days.
H. pylori Eradication (Oral): 1,000 mg/125 mg twice daily with PPI and metronidazole for 10–14 days.
Severe Infections (IV): 1 g/200 mg every 8 hours, infused over 30–40 minutes for 7–14 days.
Dosage for Children
Otitis Media (Oral, >3 months):
- 20–40 mg/kg/day (amoxicillin component) in divided doses every 8 hours (max 875 mg/125 mg per dose) for 10 days.
- Suspension: 125 mg/31.25 mg/5 mL or 250 mg/62.5 mg/5 mL, based on weight.
Sinusitis or Skin Infections (Oral, >3 months): 20–45 mg/kg/day (amoxicillin component) every 12 hours for 7–10 days.
Neonates and Infants (<3 months):
- 30 mg/kg/day (amoxicillin component) every 12 hours, under pediatrician supervision.
- IV: 25–50 mg/kg/day in divided doses every 8–12 hours.
Dosage for Pregnant Women
Pregnancy Category B: Safe if clinically indicated; consult an obstetrician, with fetal monitoring for prolonged use.
Dosage Adjustments
Renal Impairment:
- CrCl 10–30 mL/min: 500 mg/125 mg every 12 hours or 250 mg/125 mg every 8 hours.
- CrCl <10 mL/min: 500 mg/125 mg every 24 hours, avoid high doses.
Hepatic Impairment: No adjustment needed unless severe; monitor liver function.
Elderly: Start with 500 mg/125 mg every 12 hours; adjust based on renal function.
Obese Patients: Base dose on ideal body weight to avoid toxicity.
Additional Considerations
- Take oral forms with food to enhance absorption and reduce stomach upset.
- Shake suspension well and use a calibrated syringe or spoon for accurate dosing.
How to Use Amoxicillin-Clavulanate
Administration:
- Oral: Swallow tablets whole with a full glass of water, with or after food; chew tablets thoroughly if prescribed, or shake suspension and measure with a dosing device.
- IV: Reconstitute 500 mg/100 mg or 1 g/200 mg vial with 10 mL sterile water, dilute in 100 mL saline or D5W, and infuse over 30–40 minutes via a controlled pump.
- Use aseptic technique and avoid rapid bolus to minimize vein irritation.
Timing: Administer every 8–12 hours as prescribed, maintaining consistent intervals (e.g., every 8 hours for 500 mg/125 mg TID).
Monitoring: Watch for rash, diarrhea, or jaundice; check for signs of allergy (e.g., swelling) or liver dysfunction (e.g., dark urine).
Additional Tips:
- Store tablets at 15–25°C (59–77°F), suspension at 2–8°C (36–46°F) after reconstitution (use within 10 days), and IV vials at 15–30°C (59–86°F).
- Avoid refrigeration of reconstituted oral suspension if not specified; discard unused portions.
- Report severe abdominal pain, persistent vomiting, or signs of bleeding immediately.
Contraindications for Amoxicillin-Clavulanate
Hypersensitivity: Patients with a known allergy to penicillins, cephalosporins, or clavulanate.
History of Cholestatic Jaundice: Avoid in patients with prior amoxicillin-clavulanate-induced liver injury.
Severe Renal Impairment: Contraindicated if CrCl <10 mL/min without dialysis adjustment.
Mononucleosis: Avoid due to high risk of rash in infectious mononucleosis patients.
Concurrent Live Vaccines: Contraindicated during live typhoid vaccine due to reduced efficacy.
Warnings & Precautions for Amoxicillin-Clavulanate
General Warnings
Allergic Reactions: Risk of anaphylaxis, especially in penicillin-allergic patients; discontinue if rash or swelling occurs.
Hepatotoxicity: Elevated liver enzymes or cholestatic jaundice possible; monitor monthly in prolonged use.
Clostridium difficile Infection: Risk of pseudomembranous colitis; watch for diarrhea persisting beyond therapy.
Antibiotic Resistance: Overuse may promote resistant bacteria; use only as directed.
Renal Effects: Potential crystalluria or interstitial nephritis; ensure hydration.
Additional Warnings
Hematologic Toxicity: Rare thrombocytopenia or hemolytic anemia; check blood counts if symptoms arise.
Neurologic Effects: Seizures rare in renal impairment with high doses; monitor mental status.
Skin Reactions: Severe rashes (e.g., Stevens-Johnson syndrome) possible; stop if severe.
Superinfections: Risk of fungal or resistant bacterial overgrowth; assess if new symptoms appear.
Pregnancy Risks: Category B, but monitor for fetal effects with prolonged use.
Use in Specific Populations
Pregnancy: Category B; safe if clinically indicated, with fetal monitoring.
Breastfeeding: Excreted in breast milk; monitor infant for diarrhea or rash.
Elderly: Higher risk of renal and hepatic effects; adjust dose and monitor.
Children: Safe for >3 months; use lower doses in neonates under supervision.
Renal/Hepatic Impairment: Adjust dose; avoid in severe cases.
Additional Precautions
- Inform your doctor about liver disease, kidney issues, or penicillin allergy before starting this medication.
- Avoid abrupt cessation if used long-term; complete the full course.
Overdose and Management of Amoxicillin-Clavulanate
Overdose Symptoms
- Gastrointestinal distress (nausea, vomiting, diarrhea).
- Severe cases: Seizures, crystalluria, or hepatic failure.
- Hyperventilation or confusion as early signs.
- Lethargy or reduced urine output with high doses.
Immediate Actions
Contact the Medical Team: Seek immediate medical help.
Supportive Care: Administer IV fluids to enhance clearance, monitor electrolytes, and provide charcoal if ingested recently.
Specific Treatment: Use anticonvulsants for seizures, hemodialysis for severe toxicity, or supportive care for organ dysfunction.
Monitor: Check renal function, liver enzymes, and neurologic status for 24–48 hours.
Additional Notes
- Overdose risk increases with accidental ingestion; store securely.
- Report persistent symptoms (e.g., severe confusion, jaundice) promptly.
Side Effects of Amoxicillin-Clavulanate
Common Side Effects
- Diarrhea (10–20%, manageable with probiotics)
- Nausea (5–15%, reduced with food)
- Rash (5–10%, transient with mild cases)
- Vomiting (3–8%, alleviated with antiemetics)
- Headache (2–6%, common with oral use)
These effects may subside with dose adjustment or supportive care.
Serious Side Effects
- Hepatic: Jaundice, hepatitis, or liver failure.
- Renal: Crystalluria, nephritis, or acute kidney injury.
- Allergic: Anaphylaxis, angioedema, or severe rash.
- Gastrointestinal: Pseudomembranous colitis or bleeding.
- Hematologic: Thrombocytopenia or anemia.
Additional Notes
Regular monitoring for liver function, renal status, and allergic reactions is advised.
Report any unusual symptoms (e.g., dark urine, severe abdominal pain) immediately to a healthcare provider.
Drug Interactions with Amoxicillin-Clavulanate
This active ingredient may interact with:
Probenecid: Increases amoxicillin levels; reduce dose to prevent toxicity.
Allopurinol: Enhances rash risk; use cautiously.
Oral Contraceptives: May reduce efficacy; use backup contraception.
Warfarin: Increases bleeding risk; monitor INR.
Methotrexate: Raises toxicity risk; adjust dose.
Patient Education or Lifestyle
Medication Adherence: Take this antibiotic combination as prescribed to manage infections, completing the full course.
Monitoring: Report rash, diarrhea, or yellowing skin immediately.
Lifestyle: Avoid alcohol during treatment; maintain hydration.
Diet: Take with food to reduce stomach upset; avoid high-fat meals.
Emergency Awareness: Know signs of allergic reactions or liver failure; seek care if present.
Follow-Up: Schedule regular check-ups if used long-term to monitor liver and kidney function.
Pharmacokinetics
Absorption: Oral bioavailability 70–90% (amoxicillin), 50–70% (clavulanate); peak at 1–2.5 hours with food.
Distribution: Volume of distribution ~0.3 L/kg (amoxicillin), ~0.2 L/kg (clavulanate); 17–20% protein-bound.
Metabolism: Hepatic (minimal for amoxicillin, extensive for clavulanate to inactive metabolites).
Excretion: Primarily renal (50–70% unchanged); half-life 1–1.3 hours (amoxicillin), 0.8–1.2 hours (clavulanate).
Half-Life: 1–1.3 hours, prolonged in renal impairment.
Pharmacodynamics
This drug exerts its effects by:
Inhibiting bacterial cell wall synthesis via amoxicillin binding to penicillin-binding proteins.
Preventing beta-lactamase degradation with clavulanate, extending activity against resistant strains.
Exhibiting time-dependent killing, with efficacy tied to time above MIC.
Demonstrating dose-dependent gastrointestinal side effects, requiring monitoring.
Storage of Amoxicillin-Clavulanate
Temperature: Store tablets at 15–25°C (59–77°F), suspension at 2–8°C (36–46°F) after reconstitution, and IV vials at 15–30°C (59–86°F).
Protection: Keep in original container, away from moisture and heat.
Safety: Store out of reach of children.
Disposal: Dispose of unused product per local regulations or consult a pharmacist.
Frequently Asked Questions (FAQs)
Q: What does Amoxicillin-Clavulanate treat?
A: This medication treats respiratory, skin, and ear infections.
Q: Can this active ingredient cause diarrhea?
A: Yes, diarrhea may occur; use probiotics if persistent.
Q: Is Amoxicillin-Clavulanate safe for children?
A: Yes, for >3 months with a doctor’s guidance.
Q: How is this drug taken?
A: Orally or IV, as directed.
Q: How long is Amoxicillin-Clavulanate treatment?
A: 7–14 days, depending on infection.
Q: Can I use Amoxicillin-Clavulanate if pregnant?
A: Yes, with caution; consult a doctor.
Regulatory Information
This medication is approved by:
- U.S. Food and Drug Administration (FDA): Approved in 1984 (Augmentin) for bacterial infections.
- European Medicines Agency (EMA): Approved for a wide range of infections.
- Other Agencies: Approved globally for bacterial infections; consult local guidelines.
References
- U.S. Food and Drug Administration (FDA). (2025). Augmentin (Amoxicillin/Clavulanate) Prescribing Information.
- Official FDA documentation detailing the drug’s approved uses, dosage, and safety.
- European Medicines Agency (EMA). (2025). Amoxicillin/Clavulanate Summary of Product Characteristics.
- EMA’s comprehensive information on the medication’s indications and precautions in Europe.
- National Institutes of Health (NIH). (2025). Amoxicillin/Clavulanate: MedlinePlus Drug Information.
- NIH resource providing detailed information on the drug’s uses, side effects, and precautions.
- World Health Organization (WHO). (2025). WHO Model List of Essential Medicines: Amoxicillin/Clavulanate.
- WHO’s inclusion of Amoxicillin/Clavulanate for bacterial infections.
- Journal of Antimicrobial Chemotherapy. (2024). Amoxicillin/Clavulanate in Respiratory Infections.
- Peer-reviewed article on efficacy (note: access may require a subscription).
