What are the recommended treatments for muscular dystrophy?

Treatment for Muscular Dystrophy

Glucocorticoid therapy is the cornerstone of treatment for Duchenne muscular dystrophy (DMD), with daily prednisone (0.75 mg/kg/day) or deflazacort (0.9 mg/kg/day) being the first-line treatments to slow disease progression and improve mortality and quality of life outcomes. 1

Pharmacological Management

Glucocorticoid Therapy

• Prednisone (0.75 mg/kg/day) is the first-line treatment unless pre-existing weight or behavioral issues favor deflazacort 1
• Deflazacort (0.9 mg/kg/day) should be considered as first-line when there are pre-existing weight or behavioral concerns 1
• Glucocorticoid therapy significantly slows decline in muscle strength and function, reduces risk of scoliosis, and stabilizes pulmonary function 1
• Initiation timing recommendations:
  • For children <2 years: not recommended if improving (typical) 1
  • For children ≥6 years: highly recommended when reaching plateau or declining phase 1
  • Continue even when non-ambulatory to retard scoliosis, slow pulmonary function decline, and possibly prevent heart failure 1

Dosing and Administration

• Daily administration is more effective than alternate-day regimens 1
• Maximum dose: 30 mg/day for prednisone or 36 mg/day for deflazacort (at 40 kg body weight) 1
• Minimum effective dose of prednisone is approximately 0.3 mg/kg/day 1
• For patients with behavioral issues, afternoon administration after school may be preferred 1

Alternative Regimens (if side effects are unmanageable)

• Reduce daily dosage by 25-33% and reassess in 1 month 1
• Consider alternate-day dosing: prednisone 0.75-1.25 mg/kg every other day or deflazacort 2 mg/kg every other day 1
• High-dose weekend regimen: prednisone 5 mg/kg given each Friday and Saturday 1
• Intermittent regimen: prednisone 0.75 mg/kg for 10 days alternating with 10-20 days off medication 1

Respiratory Management

• Regular pulmonary function monitoring is essential 1
• Preoperative evaluation by pulmonologist at least 2 months before any surgery 1
• Assess for sleep hypoventilation with sleep studies or nocturnal oximetry 1
• Aggressive airway clearance techniques and respiratory support are essential for postoperative care 1

Cardiac Management

• ACE inhibitors or ARBs should be initiated by 10 years of age (barring contraindications) 1
• β-adrenergic blockade should be considered after ACE inhibitor/ARB initiation, especially with ventricular dysfunction or elevated heart rate 1
• Regular cardiac monitoring with ECG and echocardiogram is essential 1

Orthopedic Management

• Surgical intervention for scoliosis should be considered when Cobb angle reaches 30-50 degrees 1
• No absolute pulmonary function contraindications for surgery; some patients with FVC as low as 20% of predicted have had good outcomes 1
• Optimize cardiac, nutritional, and respiratory status before surgery 1

Multidisciplinary Care

• Regular physical and occupational therapy assessments every 4 months 1
• Routine clinic appointments every 6 months 1
• Emotional adjustment screening at every clinic visit 1
• Comprehensive neuropsychological assessment at diagnosis 1
• Social services assessment of caregivers and family 1

Important Considerations and Caveats

• Complete immunization schedule before initiating glucocorticoids 1
• Monitor for common side effects: weight gain, behavioral abnormalities, cushingoid appearance, and excessive hair growth 2, 3
• If weight gain is problematic, consider switching from prednisone to deflazacort 1, 4
• Do not abandon glucocorticoid therapy without attempting dose reduction or alternative regimens first 1
• Supplements (coenzyme Q10, carnitine, amino acids, anti-inflammatories/anti-oxidants) lack sufficient evidence for recommendation 1

Emerging Therapies

• Gene transfer therapy using adeno-associated virus (AAV) vectors and exon skipping agents are showing promise in clinical trials 5
• These approaches aim to slow disease progression in addition to relieving symptoms 5