What is the recommended dosing regimen of injectable Augmentin (amoxicillin‑clavulanate) for a 63‑year‑old adult?

Injectable Augmentin Dosing for a 63-Year-Old Adult

For a 63-year-old adult requiring injectable Augmentin (amoxicillin-clavulanate), administer 1.2 g (1000 mg amoxicillin + 200 mg clavulanate) intravenously every 8 hours, with transition to oral therapy (2 g/250 mg daily in divided doses) after 3 days if clinically improving. 1

Standard Intravenous Dosing Regimen

• The established IV dose is 1 g amoxicillin plus 200 mg clavulanic acid every 8 hours for the first 3 days of therapy. 1
• After initial IV therapy, switch to oral administration at equivalent dosing (typically 875 mg/125 mg twice daily or 500 mg/125 mg three times daily) once the patient demonstrates clinical improvement and can tolerate oral intake. 1
• Minimum treatment duration is 10 days, though this varies based on infection type and severity. 1

Age-Specific Considerations for This 63-Year-Old Patient

• At age 63, this patient falls into the "age >65 years" risk category for resistant organisms, which warrants consideration of high-dose regimens if treating acute bacterial rhinosinusitis or respiratory infections. 2
• For oral therapy following IV treatment, high-dose amoxicillin-clavulanate (4 g/250 mg per day) should be used if the patient has moderate-to-severe infection, recent antibiotic use within the past month, or comorbidities including diabetes or chronic cardiac/hepatic/renal disease. 2

Sequential IV-to-Oral Therapy Protocol

• The sequential parenteral-oral approach achieves a 96.7% clinical response rate with excellent safety profile. 3
• Clinical improvement should be evident within 72 hours; if no response occurs, reevaluate the diagnosis or switch to alternative antimicrobial therapy. 2
• The IV-to-oral switch is frequently delayed in clinical practice—transition as soon as the patient is afebrile, hemodynamically stable, and able to take oral medications (typically day 3-5). 4

Infection-Specific Dosing Adjustments

Respiratory Tract Infections

• For community-acquired pneumonia or acute bacterial rhinosinusitis in this age group, use high-dose oral formulation (2 g twice daily or 4 g/250 mg total daily) after IV therapy if risk factors for resistant Streptococcus pneumoniae exist. 2
• Respiratory tract infections showed 97.0% clinical response with sequential IV-oral therapy. 3

Skin and Soft Tissue Infections

• Standard IV dosing (1.2 g every 8 hours) achieves 95.7% clinical response rates. 3
• Duration typically 7-14 days depending on severity and source control. 3

Urinary Tract Infections

• For complicated UTIs, 5-7 days of therapy is sufficient with 97.8% clinical response. 3

Safety and Tolerance Profile

• Local tolerance at IV injection sites is excellent with minimal adverse effects. 1
• Gastrointestinal side effects occur in 3.6% (diarrhea) to 4.8% (skin reactions) of patients. 3
• Vomiting occurs rarely but may necessitate treatment discontinuation in <1% of cases. 1

Critical Pitfalls to Avoid

• Do not continue IV therapy beyond 3-5 days if the patient can tolerate oral intake—this is the most common prescribing error, leading to unnecessary IV access complications and increased costs. 4
• Do not use standard-dose oral formulations (1.75 g/250 mg daily) in this 63-year-old if treating respiratory infections—age >65 years mandates high-dose consideration. 2
• Verify renal function using estimated GFR rather than serum creatinine alone, as age-related muscle loss can mask renal impairment; dose adjustment may be needed if creatinine clearance <30 mL/min. 2
• Ensure adequate hydration before initiating therapy, particularly in elderly patients who may have reduced baseline renal reserve. 2

Duration of Therapy by Indication

• Acute bacterial rhinosinusitis: 5-7 days for mild disease, 7-10 days for moderate disease. 2
• Community-acquired pneumonia: 7-10 days total (IV + oral). 2
• Skin/soft tissue infections: 7-14 days depending on severity. 3
• Complicated intra-abdominal infections: Individualize based on source control and clinical response, typically 7-14 days. 4