What is the appropriate Augmentin (amoxicillin/clavulanate) dose for a 79‑lb (≈36‑kg) adolescent?

Augmentin Dosing for a 79-Pound Adolescent

For a 79-pound (36 kg) adolescent, the appropriate Augmentin dose depends on the infection severity and suspected pathogens: standard dosing is 45 mg/kg/day of the amoxicillin component divided twice daily (approximately 810 mg twice daily, achievable with one 875 mg tablet twice daily), while high-dose therapy is 90 mg/kg/day divided twice daily (approximately 1,620 mg twice daily) for resistant organisms or severe infections. 1

Standard-Dose Regimen (45 mg/kg/day)

• Calculation: 36 kg × 45 mg/kg/day = 1,620 mg/day total, divided into two doses = 810 mg per dose 1
• Practical administration: One Augmentin 875 mg tablet twice daily (provides 1,750 mg/day amoxicillin component) 1
• Indications: Mild to moderate community-acquired infections in fully immunized adolescents without recent antibiotic exposure, including uncomplicated sinusitis, otitis media, and community-acquired pneumonia 2
• Pathogen coverage: Effective against β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis, as well as penicillin-susceptible Streptococcus pneumoniae 2

High-Dose Regimen (90 mg/kg/day)

• Calculation: 36 kg × 90 mg/kg/day = 3,240 mg/day total, divided into two doses = 1,620 mg per dose 1
• Practical administration: Two Augmentin 875 mg tablets twice daily (provides 3,500 mg/day amoxicillin component) 1
• Indications: Moderate to severe infections, recent antibiotic exposure (within 30 days), daycare attendance, age <2 years, or suspected resistant pathogens including penicillin-resistant S. pneumoniae 2
• Pathogen coverage: Achieves sinus and middle ear fluid concentrations adequate to overcome S. pneumoniae with penicillin MICs up to 2-4 mcg/mL through altered penicillin-binding proteins 2, 1

Key Clinical Decision Points

Risk factors mandating high-dose therapy include: 2

• Attendance at daycare or school settings with high antibiotic resistance
• Antimicrobial treatment within the previous 30 days
• Age younger than 2 years (though this patient is adolescent)
• Geographic areas with >10% penicillin-nonsusceptible S. pneumoniae prevalence
• Moderate to severe illness presentation

Administration considerations: 1

• Administer at the start of meals to minimize gastrointestinal intolerance and enhance clavulanate absorption 1
• Standard treatment duration is 10 days for most respiratory infections 2
• The 875 mg tablet formulation is appropriate for adolescents and adults; do not substitute suspension formulations as they are not interchangeable due to different clavulanate ratios 1

Common Pitfalls to Avoid

• Do not use standard-dose amoxicillin/clavulanate for treatment failures: If a patient fails initial amoxicillin monotherapy, switch to high-dose amoxicillin/clavulanate (90 mg/kg/day) to provide enhanced coverage 2
• Avoid underdosing in resistant pathogen scenarios: Geographic resistance patterns matter—in areas with high penicillin-resistant S. pneumoniae prevalence, initiate high-dose therapy from the start 2
• Do not confuse formulations: The ES-600 suspension (90/6.4 mg/kg/day) is pediatric-specific and not interchangeable with standard tablets 1
• Storage matters: Tablets are stable at room temperature, but reconstituted suspensions require refrigeration and are stable for only 10 days 1, 3

Tolerability Profile

• Diarrhea occurs in approximately 7-13% of patients, with twice-daily dosing showing lower incidence than three-times-daily regimens 1, 4
• High-dose formulations (90 mg/kg/day) demonstrate similar tolerability to standard-dose formulations (45 mg/kg/day) in controlled trials 1
• Most adverse events are mild, transient gastrointestinal disturbances 5, 4, 6