What is the exact prescription for a pediatric patient weighing 8 kilograms undergoing DSTB (Diagnosis-Specific Treatment Bundle) treatment regimen 1?

DSTB Treatment Regimen 1 Prescription for 8 kg Pediatric Patient

Exact Prescription

For a pediatric patient weighing 8 kg undergoing drug-susceptible tuberculosis (DSTB) treatment regimen 1, prescribe the following intensive phase (first 2 months):

Intensive Phase (Months 1-2)

• Isoniazid: 150 mg (1½ tablets of 100 mg) once daily 1
• Rifampin: 80-160 mg daily (10-20 mg/kg) 1, 2
• Pyrazinamide: 250 mg (½ tablet of 500 mg) once daily 1
• Ethambutol: 200 mg (½ tablet of 400 mg) once daily 1

Continuation Phase (Months 3-6)

• Isoniazid: 150 mg (1½ tablets of 100 mg) once daily 1
• Rifampin: 80-160 mg daily 1, 2

Dosing Rationale

The weight-based dosing table for drug-resistant TB provides the most precise guidance for this 8 kg patient, falling in the 7-9.9 kg weight band. 1

Key Dosing Principles

• Isoniazid: Target dose is 15-20 mg/kg, which equals 120-160 mg for an 8 kg child; the 150 mg dose (1½ tablets) achieves 18.75 mg/kg 1, 2

• Pyrazinamide: Target dose is 30-40 mg/kg, which equals 240-320 mg for an 8 kg child; the 250 mg dose (½ tablet) achieves 31.25 mg/kg 1, 2

• Ethambutol: Target dose is 20-25 mg/kg for drug-resistant TB dosing, which equals 160-200 mg for an 8 kg child; the 200 mg dose (½ tablet) achieves 25 mg/kg 1

• Rifampin: Target dose is 10-20 mg/kg, which equals 80-160 mg for an 8 kg child 1, 2

Critical Administration Details

Medication Preparation

• Tablets should be crushed and mixed with food or liquid to facilitate administration in this young child, as pediatric formulations are often unavailable 1

• Spread doses throughout the day if gastrointestinal intolerance occurs, though this complicates directly observed therapy (DOT) 1

Essential Adjunctive Therapy

• Pyridoxine (Vitamin B6) supplementation is mandatory for infants and young children receiving isoniazid to prevent peripheral neuropathy 1, 2

Monitoring Requirements

• Monthly visual acuity assessment for ethambutol toxicity, though challenging in young children; baseline ophthalmologic examination is recommended 1, 2

• Recalculate all doses monthly as the child gains weight to maintain therapeutic drug levels 1, 2

Treatment Delivery

Directly observed therapy (DOT) is mandatory for all pediatric TB patients to ensure adherence throughout the 6-month treatment course. 1, 2

• Parents cannot be relied upon to supervise DOT; a healthcare worker must directly observe medication administration 1

• Five-day-per-week DOT is acceptable when daily observation is not feasible, with dose adjustments accordingly 1

Common Pitfalls to Avoid

• Do not delay ethambutol inclusion while awaiting drug susceptibility testing unless drug resistance is highly unlikely; include it in the initial regimen 2, 3

• Do not use three-times-weekly therapy in children, as it is not recommended 1

• Do not fail to obtain baseline cultures before starting therapy to confirm susceptibility and assess for HIV co-infection, which may require longer treatment 2

• Do not use adult fixed-dose combinations, as they cannot be appropriately adjusted for pediatric weight-based dosing 1, 4

Duration Modifications

• Extend treatment to 9-12 months for disseminated disease or CNS involvement (tuberculous meningitis) 1, 2

• For isolated lymph node TB or minimal disease, the standard 6-month regimen is appropriate 1, 2