Recommended Doses of Streptomycin, Levofloxacin, and Ethambutol
For drug-susceptible tuberculosis in adults, use ethambutol 15 mg/kg daily (maximum 2.5g), levofloxacin 750-1,000 mg daily, and streptomycin 15 mg/kg daily (maximum 1g) initially, with dose adjustments based on age, renal function, and treatment phase. 1
Ethambutol Dosing
Standard Adult Dosing
- Daily regimen: 15 mg/kg daily (typically 1,200-1,600 mg for most adults) 1
- Twice-weekly regimen: 25 mg/kg per dose 1
- Thrice-weekly regimen: 25 mg/kg per dose 1
- Maximum daily dose: 2.5 grams 1
Pediatric Dosing
- Daily regimen: 20 mg/kg (range 15-25 mg/kg) 1, 2
- Twice-weekly regimen: 50 mg/kg 1
- Children can safely receive 20 mg/kg daily and 30 mg/kg three times weekly without undue concern for ocular toxicity 2
- For children in lower weight bands (<55 kg), doses may need adjustment: 825 mg if <37.9 kg and 1,100 mg if 38-54.9 kg to achieve adequate drug exposures 3
Renal Impairment Adjustments
- Creatinine clearance <30 mL/min or hemodialysis: 15-25 mg/kg per dose three times weekly (not daily) 1
- Administer after hemodialysis on dialysis days 1
Levofloxacin Dosing
Standard Adult Dosing
- For drug-susceptible TB: 750-1,000 mg once daily 1
- For multidrug-resistant TB: 1,000 mg daily achieves target exposure in nearly all adults and is well tolerated 4
- Doses >1,000 mg/day result in greater exposures and increased adverse events without faster culture conversion 4
Pediatric Dosing
- Children ≥2 years: 15-20 mg/kg daily to achieve target concentrations (Cmax ≥8 µg/mL) 5
- Children >5 years: 10 mg/kg daily 5
- Children ≤5 years: 15-20 mg/kg daily 5
- For tuberculous meningitis in children: 19-33 mg/kg daily may be needed to attain exposure targets 6
Renal Impairment Adjustments
- Creatinine clearance <30 mL/min or hemodialysis: 750-1,000 mg per dose three times weekly (not daily) 1
- Administer after hemodialysis on dialysis days 1
Streptomycin Dosing
Standard Adult Dosing
- Initial intensive phase (daily): 15 mg/kg daily (maximum 1g), given 5-7 days per week for first 2-4 months 1, 7
- Continuation phase (intermittent): 12-15 mg/kg per dose, 2-3 times weekly after culture conversion 7
- Patients >59 years: Automatic dose reduction to 10 mg/kg daily (maximum 750 mg) due to increased risk of nephrotoxicity and ototoxicity 7
Pediatric Dosing
- Daily regimen: 15 mg/kg daily 1
- Twice-weekly regimen: Not recommended 1
- Thrice-weekly regimen: Not recommended 1
Renal Impairment Adjustments
- Creatinine clearance <30 mL/min or hemodialysis: 12-15 mg/kg per dose, 2-3 times weekly (not daily) 1, 7
- Maintain the per-dose amount (do not reduce) to preserve concentration-dependent bactericidal effect 1, 7
- Administer after hemodialysis on dialysis days 1
Critical Clinical Considerations
Monitoring Requirements
- Ethambutol: Baseline visual acuity testing (Snellen chart) before starting; monthly questioning about visual symptoms 8
- Levofloxacin: No specific monitoring beyond standard adverse event assessment 1
- Streptomycin: Baseline audiogram, vestibular testing, and serum creatinine; monthly renal function and auditory/vestibular symptom assessment 7
Common Pitfalls to Avoid
- Do not reduce per-dose amounts of streptomycin in renal failure—instead increase the dosing interval to maintain concentration-dependent killing 1, 7
- Do not use levofloxacin doses >1,000 mg/day in adults, as this increases toxicity without improving efficacy 4
- Do not underdose ethambutol in children—they require higher mg/kg doses than adults to achieve comparable serum concentrations 3, 2
- Always administer drugs after hemodialysis to facilitate directly observed therapy and avoid premature drug removal 1