What is the standard dose and duration of amoxicillin (amoxicillin) for a 175-pound male with pneumonia?

Amoxicillin Dosing for Community-Acquired Pneumonia in a 175lb Male

For a 175-pound (79.5 kg) male with community-acquired pneumonia, the recommended dose is amoxicillin 1 gram orally three times daily for 5-7 days, assuming he has no comorbidities or risk factors for resistant pathogens. 1

Dose Selection Based on Patient Risk Profile

For Healthy Patients Without Comorbidities

• Amoxicillin 1 gram orally every 8 hours (three times daily) is the preferred regimen 1
• This high-dose regimen has demonstrated efficacy in multiple inpatient CAP studies despite lack of atypical organism coverage 1
• The FDA-approved dosing for lower respiratory tract infections supports 875 mg every 12 hours or 500 mg every 8 hours for severe infections, but guideline recommendations favor the 1 gram three times daily dosing for pneumonia specifically 2

For Patients With Comorbidities

If this patient has chronic heart, lung, liver, or renal disease; diabetes; alcoholism; malignancy; or asplenia, combination therapy is required: 1

• Amoxicillin-clavulanate 875 mg/125 mg twice daily PLUS a macrolide (azithromycin 500 mg day 1, then 250 mg daily) 1
• Alternative: Amoxicillin-clavulanate 500 mg/125 mg three times daily PLUS macrolide 1
• Monotherapy alternative: Respiratory fluoroquinolone (levofloxacin 750 mg daily or moxifloxacin 400 mg daily) 1

Treatment Duration

5-7 days is the evidence-based duration for community-acquired pneumonia in responding patients. 1, 3, 4

• European guidelines recommend treatment should generally not exceed 8 days in a responding patient 1
• Meta-analyses demonstrate that antibiotic regimens of 7 days or less are equally effective as longer courses for mild to moderate CAP 4
• Recent evidence supports durations as short as 3 days for hospitalized CAP, though 5-7 days remains standard 3
• Treatment should continue for a minimum of 48-72 hours beyond clinical improvement or bacterial eradication 2

Critical Dosing Considerations

High-Dose Rationale

The 1 gram three times daily dosing (versus lower doses like 500 mg three times daily) is preferred because: 1

• Provides better coverage in areas with penicillin-resistant Streptococcus pneumoniae 1
• More appropriate for moderate disease severity 1
• Addresses potential resistant pathogens more effectively 1

Timing and Administration

• Initiate antibiotics immediately upon diagnosis - delays in appropriate therapy increase mortality 1
• Take at the start of meals to minimize gastrointestinal intolerance 2
• For severe pneumonia requiring hospitalization, intravenous therapy may be initiated with switch to oral when clinically stable 1

Common Pitfalls to Avoid

Do not use amoxicillin monotherapy if:

• Patient has received antibiotics within the past 4-6 weeks (risk of resistant organisms) 1
• Patient has comorbidities listed above (requires combination therapy or fluoroquinolone) 1
• Legionella or gram-negative organisms are suspected (requires macrolide or fluoroquinolone coverage) 1

Do not underdose: The 500 mg three times daily regimen is insufficient for pneumonia; 1 gram three times daily is required for adequate pneumococcal coverage 1

Do not extend treatment unnecessarily: Continuing antibiotics beyond 7 days in a responding patient increases resistance risk without improving outcomes 1, 3, 4

Renal Dosing Adjustment

For this 175-pound male with normal renal function, no adjustment is needed. However, if creatinine clearance is <30 mL/min, reduce to 500 mg every 12 hours; if <10 mL/min, reduce to 500 mg every 24 hours 2