What is the recommended dose of Deflazacort (Deflazacort) for various conditions?

Deflazacort Dosing Recommendations

The recommended dose of deflazacort is 0.9 mg/kg/day administered orally once daily, which is the FDA-approved and guideline-endorsed standard for Duchenne muscular dystrophy in patients 5 years and older. 1, 2

Primary Indication: Duchenne Muscular Dystrophy

Standard Dosing

• Administer deflazacort at 0.9 mg/kg/day once daily for DMD patients aged 5 years and older 2
• Round up to the nearest possible tablet dose when using tablets 2
• Can be taken with or without food, but avoid grapefruit juice 2
• The American Academy of Neurology specifically recommends this 0.9 mg/kg/day dosing for patients aged 6 years and older who are at a plateau or declining phase 1

Evidence Supporting Standard Dose

• A 2022 non-inferiority trial directly compared 0.45 mg/kg/day versus 0.9 mg/kg/day and found that the lower dose failed to meet non-inferiority criteria, with a mean difference of 24.8 meters in 6-minute walk distance favoring the standard dose 3
• The standard 0.9 mg/kg/day dose (protocol-T) demonstrated superior outcomes compared to intermittent dosing: 100% ambulatory at 9 years, 83% at 12 years, and 77% at 15 years, versus lower rates with alternative protocols 4
• Daily dosing at 0.9 mg/kg/day resulted in only 16% developing scoliosis >20 degrees versus 90% in untreated controls 4

Lower Dose Considerations (Not Recommended as Standard)

• The 0.45 mg/kg/day dose showed non-inferiority only in specific subgroups: boys ≤7 years of age and those with baseline 6-minute walk distance >350 meters 3
• However, this lower dose had significantly fewer moderate-to-severe adverse events (odds ratio 0.36) 3
• Despite this safety advantage, the lower dose is not recommended as standard therapy given the failure to meet non-inferiority for the primary efficacy endpoint 3

Pre-Treatment Requirements

Immunization Protocol

• Complete all immunizations according to guidelines before starting deflazacort, particularly varicella vaccination 1, 2
• Administer live-attenuated or live vaccines at least 4-6 weeks prior to initiating therapy 2
• Provide families with a steroid card listing emergency-care considerations 1

Dose Modifications

With CYP3A4 Inhibitors

• Reduce dose to one-third (approximately 0.3 mg/kg/day) when co-administered with moderate or strong CYP3A4 inhibitors 2
• For example, a 36 mg daily dose should be reduced to 12 mg daily 2

With CYP3A4 Inducers

• Avoid concurrent use of moderate or strong CYP3A4 inducers with deflazacort 2

Discontinuation Protocol

• Taper deflazacort gradually if administered for more than a few days to avoid acute adrenal insufficiency 2
• Abrupt withdrawal can cause potentially fatal adrenal crisis due to HPA axis suppression 2

Secondary Indications (Non-DMD)

Allergic Bronchopulmonary Aspergillosis/Mycosis

• Initial dose: 0.75 mg/kg/day for 4 weeks 1
• Taper: Decrease by half every 4 weeks for 2 months 1
• Final taper: Reduce by 6 mg every 2 weeks until discontinuation 1

Autoimmune Hepatitis

• Use as alternative glucocorticoid in patients intolerant to standard therapy 1
• Specific dosing not provided in guidelines, but generally follows corticosteroid equivalency principles 1

Nephrotic Syndrome (Pediatric)

• Alternative to prednisolone for first episode in children 1

Monitoring Requirements

Ophthalmologic Surveillance

• Annual ophthalmological examinations to monitor for cataracts 1
• Cataracts develop in approximately 30% of patients on daily 0.9 mg/kg/day dosing, though typically asymptomatic and not requiring treatment 4

Bone Health Monitoring

• Annual DEXA scans for bone density 1
• Annual vitamin D level monitoring 1
• Fracture rates appear similar to untreated patients (16-19% versus 16-20% in controls) 4

Growth Monitoring (Pediatric)

• Height monitoring at least every 6 months in children 1

Endocrine Monitoring

• Monitor for Cushing's syndrome and hyperglycemia during chronic use 2
• Assess for adrenal insufficiency if discontinuing therapy 2

Clinical Pitfalls to Avoid

• Do not use lower doses than 0.9 mg/kg/day as standard therapy despite better tolerability, as efficacy is compromised 3
• Never abruptly discontinue after prolonged use due to risk of adrenal crisis 2
• Do not forget dose adjustment when adding CYP3A4 inhibitors, as this can lead to excessive corticosteroid exposure 2
• Deflazacort should be considered first-line over prednisone in DMD patients with pre-existing weight or behavioral issues due to more favorable side effect profile 1