What is the recommended levofloxacin dosing regimen for pediatric patients, including weight‑based dose, maximum dose, and typical treatment duration for common infections?

Levofloxacin Pediatric Dosing

For children ≥6 months to <5 years, administer levofloxacin 10 mg/kg every 12 hours (maximum 250 mg per dose); for children ≥5 years, use 10 mg/kg once daily (maximum 750 mg daily). 1

Standard Dosing by Age Group

Children 6 Months to <5 Years

• Dose: 10 mg/kg every 12 hours (maximum 250 mg per dose, 500 mg daily total) 1
• This twice-daily regimen is necessary because children in this age group clear levofloxacin nearly twice as fast as adults (clearance 0.28-0.32 L/h/kg), resulting in approximately half the systemic exposure of adults when given equivalent mg/kg doses 1
• Clearance reaches 50% maturation at approximately 2 months of age and 100% maturation by 2 years, necessitating higher weight-adjusted doses in younger children 2, 3

Children ≥5 Years to 16 Years

• Dose: 10 mg/kg once daily (maximum 750 mg daily) 1
• Once-daily dosing is appropriate in this age group as levofloxacin elimination approaches adult rates 1

Adolescents ≥15 Years

• Adult dosing applies: 500-1,000 mg once daily 4

Formulation-Specific Considerations

Dispersible Tablets (100 mg)

• Preferred formulation when available due to 29% higher bioavailability compared to crushed non-dispersible tablets 3
• Recent pharmacokinetic data suggest higher doses may be needed: 16-33 mg/kg for dispersible tablets to achieve adult-equivalent exposures 3

Non-Dispersible Tablets (250 mg, 500 mg, 750 mg)

• Must be crushed or split for weight-based dosing in smaller children 5
• 21.5-29% reduced bioavailability compared to dispersible formulation 6, 3
• May require doses of 20-50 mg/kg to compensate for reduced bioavailability 3

Indication-Specific Dosing

Multidrug-Resistant Tuberculosis (Primary Indication)

• Weight-based dosing table for MDR-TB treatment: 5

Weight (kg)	Total Daily Dose (mg)	Typical Regimen
5-6.9	150	75 mg BID
7-9.9	200	100 mg BID
10-13.9	300	150 mg BID
14-19.9	400	200 mg BID
20-29.9	600	300 mg BID
30-39.9	800	400 mg BID
≥40	1,200	600 mg BID or QD

• The American Thoracic Society recommends 15-20 mg/kg/day (maximum 1.0 g/day) for tuberculosis treatment, though this may result in lower exposures than adults 4, 5

Inhalational Anthrax Post-Exposure (FDA-Approved)

• 8 mg/kg twice daily (based on pharmacometric modeling to match adult 500 mg once-daily exposure) 7
• This is the only FDA-approved pediatric indication for levofloxacin 7

Critical Safety Considerations and Restrictions

When to Use Levofloxacin in Children

• Reserve for multidrug-resistant tuberculosis as the primary indication 5
• Consider when there is intolerance to first-line agents or proven resistance to both isoniazid and rifampin 5
• May be used for inhalational anthrax post-exposure 7
• Fluoroquinolones should not be used for long-term treatment (>several weeks) due to potential effects on bone and cartilage growth 5

Contraindications and Cautions

• Avoid prolonged use due to concerns about cartilage development in weight-bearing joints 5
• Do not administer within 2 hours of antacids or medications containing divalent cations (calcium, magnesium, aluminum, iron), as this decreases fluoroquinolone absorption by up to 50% 5

Renal Dosing Adjustments

• Adjust dose if creatinine clearance <50 mL/minute, as levofloxacin is 80% renally cleared 5
• Supplemental doses are not necessary after hemodialysis 5

Common Dosing Pitfalls

Pitfall #1: Using Adult Fixed Doses

• Never use adult fixed doses (500 mg or 750 mg) in children <40 kg without weight-based calculation 5
• This leads to overdosing in smaller children or underdosing in heavier children 5

Pitfall #2: Underdosing Due to Faster Clearance

• Current WHO-recommended doses result in approximately half the exposure in adults for children <24 kg and <10 years 3
• Children <5 years require twice-daily dosing due to clearance rates nearly double that of adults 1

Pitfall #3: Ignoring Formulation Differences

• Crushed non-dispersible tablets have significantly lower bioavailability than dispersible formulations 6, 3
• When using crushed tablets, consider that exposures may be 21-29% lower than expected 6, 3

Pitfall #4: Drug Interactions

• Failure to separate levofloxacin from multivalent cation-containing products by at least 2 hours can reduce absorption substantially 5

Monitoring Requirements

• Regular monitoring for adverse effects is recommended, particularly with prolonged use 5
• Monitor for musculoskeletal adverse events (arthralgia, tendinopathy) 5
• Assess renal function and adjust dose accordingly 5