Oral Antibiotic Dosing for Adults
For adults without CNS infection or special comorbidities, amoxicillin should be dosed at 500 mg twice daily, and ciprofloxacin at 500-700 mg twice daily. 1
Amoxicillin Dosing
- Standard adult dose: 500 mg twice daily (BID) 1
- For resistant organisms (particularly penicillin-resistant Streptococcus pneumoniae), the dose can be increased to a maximum of 1,000 mg every 12 hours 1
- When combined with clavulanate, dosing ranges from 500-875 mg twice daily based on the amoxicillin component, with a maximum adult dose of 4.0 g twice daily 1
Ciprofloxacin Dosing
- Standard adult dose: 500-700 mg twice daily (BID) 1
- For mild-to-moderate infections, 500 mg twice daily is appropriate 2
- For severe or complicated infections, 750 mg twice daily should be used 2
- For acute uncomplicated pyelonephritis, 500-750 mg twice daily for 7 days is effective with clinical cure rates exceeding 90% 2
Important Clinical Considerations
Amoxicillin
- The choice between standard and high-dose amoxicillin depends on local resistance patterns for S. pneumoniae 1
- In geographic areas where 25-50% of S. pneumoniae strains show penicillin resistance, higher doses may be necessary to overcome resistance mediated by altered penicillin-binding proteins 1
Ciprofloxacin
- Severity assessment is the key driver for dose selection between 500 mg and 750 mg twice daily 2
- For prolonged therapy (>14 days), monitoring for adverse effects is recommended, including ECG monitoring at baseline and 2 weeks, and blood glucose monitoring in diabetic patients 2
- Standard duration for most infections is 7-14 days, though specific infections may require longer courses 2