Co-amoxiclav

1. Introduction

Co-amoxiclav, a combination of amoxicillin (a penicillin-class antibiotic) and clavulanic acid (a beta-lactamase inhibitor), is used to treat bacterial infections resistant to amoxicillin alone. Clavulanic acid prevents the breakdown of amoxicillin by beta-lactamase-producing bacteria, thereby broadening its spectrum of activity.

2. Indications

  • Approved Indications:
    • Respiratory tract infections (e.g., sinusitis, pneumonia).
    • Urinary tract infections (UTIs).
    • Skin and soft tissue infections (e.g., cellulitis).
    • Bone and joint infections (e.g., osteomyelitis).
    • Dental infections (e.g., abscesses).
    • Acute otitis media in children.
  • Off-Label Uses:
    • Prevention of surgical site infections in certain surgeries.

3. Dosage

  • Adults and Children >40 kg:
    • 500/125 mg every 8 hours or 875/125 mg every 12 hours.
    • Severe infections: 1000/125 mg every 8 hours.
  • Children (<40 kg):
    • 20–40 mg/kg/day in divided doses every 8 hours for mild to moderate infections.
    • 40–90 mg/kg/day in divided doses every 8–12 hours for severe infections.
  • Renal Impairment:
    • Adjust dosage based on creatinine clearance.

4. Administration

  • Take orally with food to reduce gastrointestinal side effects.
  • Use the suspension formulation for children or those with difficulty swallowing tablets.
  • Shake the suspension well before use and use a calibrated measuring device for dosing.

5. Forms Available

  • Tablets: 500/125 mg, 875/125 mg, 1000/125 mg.
  • Suspension: 125/31.25 mg/5 mL, 250/62.5 mg/5 mL, 400/57 mg/5 mL.
  • Intravenous: 500/100 mg, 1000/200 mg vials.

6. Side Effects

6.1. Common Side Effects

  • Diarrhoea.
  • Nausea and vomiting.
  • Rash.

6.2. Less Common Side Effects

  • Abdominal pain.
  • Headache.
  • Fatigue.

6.3. Rare but Serious Side Effects

  • Clostridioides difficile-associated diarrhoea.
  • Liver dysfunction (elevated liver enzymes, jaundice).
  • Severe allergic reactions (e.g., anaphylaxis, angioedema).

7. Warnings

  • Avoid in patients with a history of hypersensitivity to penicillins or cephalosporins.
  • Monitor for signs of serious allergic reactions and stop the medication if they occur.
  • Prolonged use may lead to fungal or bacterial superinfections.

8. Precautions

  • Use cautiously in patients with hepatic dysfunction or a history of liver issues associated with co-amoxiclav.
  • Monitor renal function in elderly patients and those with renal impairment.
  • Use with caution in patients with infectious mononucleosis, as amoxicillin can cause a rash in these individuals.

9. Interactions

  • Drug-Drug Interactions:
    • Methotrexate: Increased toxicity due to reduced methotrexate excretion.
    • Warfarin: Increased risk of bleeding; monitor INR closely.
    • Probenecid: Increases amoxicillin levels by reducing renal excretion.
  • Drug-Food Interactions:
    • Food enhances absorption of clavulanic acid.

10. Monitoring Parameters

  • Symptom improvement in infection (e.g., fever, pain, inflammation).
  • Liver function tests, especially during prolonged therapy.
  • Monitor for diarrhoea or signs of C. difficile infection.

11. Use in Children

  • Approved for use in children; suspension formulations are recommended for accurate dosing based on weight.

12. Use in Pregnancy

  • Category B: Generally safe to use in pregnancy, but consult a doctor before starting treatment.
  • No evidence of teratogenic effects in human studies.

13. Use in Elderly

  • Safe for use in elderly patients but monitor for renal function and adjust doses in renal impairment.

14. Use in Kidney Disease

  • Dose adjustments are required based on the degree of renal impairment:
    • CrCl 10–30 mL/min: 500/125 mg every 12 hours.
    • CrCl <10 mL/min: 500/125 mg every 24 hours.
    • Haemodialysis: One dose during dialysis and one dose after dialysis.

15. Use in Liver Disease

  • Use with caution in patients with a history of liver dysfunction or cholestatic jaundice associated with co-amoxiclav.

16. Patient Counselling Points

  • Take with food to reduce stomach upset.
  • Complete the full course of treatment, even if symptoms improve early.
  • Report any signs of allergic reactions, such as rash, swelling, or difficulty breathing, immediately.
  • Notify your doctor if you experience persistent diarrhoea, abdominal pain, or jaundice.
  • Shake the suspension well before use and store it in the refrigerator; discard any unused portion after 7–10 days.

17. Table of Brand Names, Manufacturers, and Prices

Brand NameManufacturerPrice (USD)
AugmentinGSK$25–40 (14 tablets, 875/125 mg)
ClavamCipla$15–25 (10 tablets, 625 mg)
Generic OptionsVarious$10–20 (10 tablets, 625 mg)

18. FAQs (15 Questions)

  1. What is co-amoxiclav used for?
    It is used to treat bacterial infections such as sinusitis, pneumonia, and skin infections.
  2. How does co-amoxiclav work?
    Amoxicillin kills bacteria, while clavulanic acid prevents the breakdown of amoxicillin by bacterial enzymes.
  3. Can co-amoxiclav treat viral infections?
    No, it is only effective against bacterial infections.
  4. What are the common side effects of co-amoxiclav?
    Diarrhoea, nausea, vomiting, and rash are common side effects.
  5. How should co-amoxiclav be taken?
    It should be taken with food to reduce gastrointestinal side effects.
  6. Is co-amoxiclav safe during pregnancy?
    Yes, it is generally considered safe, but consult your doctor before starting treatment.
  7. Can children take co-amoxiclav?
    Yes, it is safe for children when dosed appropriately based on weight.
  8. What should I do if I miss a dose?
    Take it as soon as you remember, but skip it if it’s close to the next dose. Do not double up.
  9. Can co-amoxiclav cause allergic reactions?
    Yes, allergic reactions like rash or swelling can occur. Stop the medication and seek medical attention if this happens.
  10. How long does co-amoxiclav take to work?
    Symptom improvement is usually seen within 2–3 days, but the full course must be completed.
  11. Does co-amoxiclav interact with other medications?
    Yes, it interacts with warfarin, methotrexate, and probenecid.
  12. How should co-amoxiclav be stored?
    Tablets should be stored at room temperature. Suspension should be refrigerated and discarded after 7–10 days.
  13. Can co-amoxiclav cause diarrhoea?
    Yes, diarrhoea is a common side effect. Report severe or bloody diarrhoea to your doctor immediately.
  14. Can co-amoxiclav treat urinary tract infections?
    Yes, it is commonly used for UTIs caused by susceptible bacteria.
  15. What should I do if symptoms do not improve?
    Consult your doctor if symptoms persist after completing the prescribed course.