Can Augmentin (amoxicillin-clavulanate) be taken once a day?

Augmentin (Amoxicillin-Clavulanate) Cannot Be Taken Once Daily

Augmentin (amoxicillin-clavulanate) should be taken twice daily in adults, not once daily, as the standard dosing regimen requires multiple daily doses to maintain effective antimicrobial concentrations. The pharmacokinetic properties of amoxicillin-clavulanate do not support once-daily dosing for any approved indication.

Standard Dosing Guidelines for Augmentin

Adult Dosing

• Standard adult dosing: 875 mg amoxicillin/125 mg clavulanate twice daily 1
• Maximum daily dose: 1750 mg of amoxicillin component per day 1
• Common indications with twice-daily dosing:
  • Sinusitis: 875/125 mg twice daily for 7-10 days 1
  • Skin and soft tissue infections: 875/125 mg twice daily 1
  • Complicated UTIs: 875/125 mg twice daily for 10-14 days 1

Pediatric Dosing

• Standard pediatric dosing is 40 mg/kg/day of amoxicillin component in three divided doses 1
• For certain infections requiring higher doses: 90 mg/kg/day divided into 2-3 doses 1

Why Once-Daily Dosing Is Not Appropriate

1. Pharmacokinetic limitations:

   • The half-life of amoxicillin and clavulanate is relatively short, requiring multiple daily doses to maintain therapeutic concentrations
   • Once-daily dosing would result in subtherapeutic levels for much of the 24-hour period

2. Evidence from guidelines:

   • All major treatment guidelines specify multiple daily doses for amoxicillin-clavulanate
   • The 2015 Adult Sinusitis Clinical Practice Guideline specifically recommends twice-daily dosing 2
   • Even high-dose formulations (Augmentin XR) require twice-daily administration 3

3. Risk of treatment failure and resistance development:

   • Subtherapeutic levels from once-daily dosing could lead to treatment failure
   • Inadequate dosing may promote the development of antibiotic resistance 1

Special Considerations

Renal Impairment

• Dose adjustment is required for patients with creatinine clearance <30 mL/min 1
• Even with dose adjustments, multiple daily doses are still required

Hepatic Impairment

• Liver function should be monitored when using amoxicillin-clavulanate 1
• Dosing frequency is not reduced for hepatic impairment

Historical Context

Early studies from the 1980s used three-times-daily dosing:

• A 1982 study used 375 mg three times daily for urinary tract infections 4
• Another 1982 study for various infections used dosing that included clavulanic acid up to 1.0 g/day in divided doses 5

Common Pitfalls to Avoid

1. Confusing with other antibiotics: Some antibiotics (like certain fluoroquinolones or ceftriaxone) can be dosed once daily, but this does not apply to amoxicillin-clavulanate

2. Medication adherence concerns: While once-daily dosing would improve adherence, it is not pharmacologically appropriate for amoxicillin-clavulanate

3. Inadequate therapy: Attempting once-daily dosing could result in treatment failure and potentially contribute to antibiotic resistance

In conclusion, Augmentin must be administered at least twice daily in adults to maintain effective antimicrobial concentrations. No formulation or indication supports once-daily dosing of this medication.