Levofloxacin Dosing for Tuberculosis
For adults with drug-resistant TB, use levofloxacin 750-1000 mg once daily; for children, use 15-20 mg/kg once daily (up to 20-30 mg/kg for optimal exposure), with doses adjusted by weight bands using available tablet formulations.
Adult Dosing
Standard Dosing for Drug-Resistant TB
- 750-1000 mg once daily orally is the recommended dose for rifampin-resistant TB 1
- The FDA-approved dosing range is 250-750 mg every 24 hours, though higher doses are used off-label for TB 1
- Pharmacokinetic/pharmacodynamic studies demonstrate that 1500 mg daily may be required to achieve optimal target exposures (AUC/MIC ratio of 146 for maximal kill, 360 for resistance suppression) particularly for strains with MIC ≥1 mg/L 2
- For practical clinical use, 750-1000 mg daily represents a balance between efficacy and safety, with 1500 mg reserved for difficult cases 2, 3
Renal Dose Adjustments
When creatinine clearance is <50 mL/min, dose adjustments are mandatory 1:
- CrCl 20-49 mL/min: Initial 750 mg, then 750 mg every 48 hours OR 500 mg every 24 hours
- CrCl 10-19 mL/min: Initial 750 mg, then 500 mg every 48 hours
- Hemodialysis/CAPD: Initial 750 mg, then 500 mg every 48 hours
Pediatric Dosing
Children with Drug-Resistant TB (Active Disease)
15-20 mg/kg once daily is the WHO-recommended dose, but recent evidence suggests this may be suboptimal 4, 5:
- For children <5 years: 15-20 mg/kg once daily, given twice daily to improve exposure 4
- For children ≥5 years: 15-20 mg/kg once daily 4
- Optimal dosing based on recent pharmacokinetic data: 20-30 mg/kg once daily achieves target fAUC/MIC of 100 6
Weight-Band Dosing Using 250 mg Tablets 4
This practical approach uses the adult 250 mg formulation:
- 7-9.9 kg: 200 mg (½ tablet) = ~20-28 mg/kg
- 10-13.9 kg: 200 mg (½ tablet) = ~14-20 mg/kg
- 14-19.9 kg: 300 mg (¾ tablet) = ~15-21 mg/kg
- 20-29.9 kg: 400 mg (1 tablet) = ~13-20 mg/kg
- 30-39.9 kg: 600 mg (1½ tablets) = ~15-20 mg/kg
- ≥40 kg: 800 mg (2 tablets) = ~20 mg/kg
Critical Pediatric Considerations
- Children <2 years have immature clearance requiring age-adjusted dosing; clearance reaches 50% of adult values at 2 months and 100% by 2 years 5
- HIV-infected children have 16% reduced clearance, though dose adjustment is typically not required 5
- Current WHO-recommended doses (15-20 mg/kg) result in substantially lower exposures than adults receiving similar mg/kg doses, supporting the use of higher doses (20-30 mg/kg) 5, 6
- For children using 100 mg dispersible tablets: doses range from 8-33 mg/kg by weight band 7
TB Preventive Treatment (MDR/RR-TB Exposure)
Adults and Adolescents ≥14 Years
- 750 mg once daily for 6 months is the WHO-recommended regimen for contacts of MDR/RR-TB 8
Children
- 15-20 mg/kg once daily for 6 months (24 weeks) 9
- This regimen showed a hazard ratio of 0.44 (95% CI 0.15-1.25) for preventing TB disease, though not statistically significant 9
- Safety profile was acceptable with grade 3+ adverse events comparable to placebo 9
Administration Guidelines
Timing and Food
- Can be administered without regard to food 1
- Separate from antacids, sucralfate, iron, multivitamins with zinc by at least 2 hours before or after levofloxacin 1
Formulation Considerations
- Tablets can be crushed for children unable to swallow whole tablets 5
- Crushing tablets may affect bioavailability; children receiving crushed tablets had lower exposures than expected 5
- 100 mg dispersible tablets are preferred for young children when available 7
Key Clinical Pitfalls
Underdosing in children: The standard 15-20 mg/kg dose achieves lower exposures than adults; consider 20-30 mg/kg for active disease 5, 6
Renal function monitoring: Always check creatinine clearance before initiating therapy and adjust accordingly 1
Drug interactions: Fluoroquinolones chelate with divalent/trivalent cations—ensure proper spacing 1
Pregnancy: Levofloxacin AUC is lower in second trimester than third trimester or postpartum, but standard dosing appears adequate 10
Musculoskeletal toxicity: Monitor for tendonitis, particularly in children (1 case of grade 2 tendonitis reported in preventive treatment trial) 9
Duration considerations: For active MDR-TB, levofloxacin is typically continued for the entire treatment duration (6-24 months depending on regimen); for preventive treatment, 6 months is standard 11, 9