From the Guidelines
Paget's disease of bone is a chronic disorder that requires immediate treatment with bisphosphonates to prevent complications and improve quality of life, with zoledronic acid (5mg IV once) being the most effective option, as supported by recent studies 1.
Overview of Paget's Disease
Paget's disease of bone is a chronic disorder characterized by abnormal bone remodeling, resulting in enlarged and deformed bones. It typically affects older adults and can cause bone pain, fractures, hearing loss, and other complications.
Treatment Options
Treatment focuses on controlling symptoms and preventing complications. Bisphosphonates are the first-line medication, with alternative options including oral alendronate (40mg daily for 6 months) or risedronate (30mg daily for 2 months) 1.
- Calcium (1000-1500mg daily) and vitamin D (800-1000 IU daily) supplements should accompany treatment to prevent hypocalcemia.
- Treatment is indicated for patients with symptoms, involvement of weight-bearing bones, vertebrae, or skull, elevated alkaline phosphatase levels (>2-3 times normal), or before orthopedic surgery.
Disease Pathophysiology
The disease results from overactive osteoclasts causing excessive bone breakdown followed by disorganized bone formation.
- Regular monitoring of alkaline phosphatase levels helps assess treatment response, with levels typically normalizing within 3-6 months of effective therapy.
- Pain management with NSAIDs or acetaminophen may be needed during initial treatment phases.
Associated Risks and Considerations
Paget's disease is associated with an increased risk of osteosarcoma, particularly in adults over 65 years old 1.
- A thorough diagnostic workup is essential to rule out other conditions, such as osteomalacia, hypophosphatasia, and fibrous dysplasia 1.
- Treatment should be individualized based on the patient's specific needs and disease severity.
From the Research
Definition and Characteristics of Paget's Disease
- Paget's disease of bone is a metabolic bone disease characterized by localized areas of excessive bone resorption coupled with accelerated bone formation, resulting in new bone that is less structurally organized and weaker than normal bone 2.
- The disease can lead to complications such as bone pain, osteoarthritis, skeletal deformity, hearing loss, and fractures 2.
Epidemiology of Paget's Disease
- Paget's disease affects an estimated 2-7% of persons of age 55 years or older in North America and western Europe 2.
- The etiology of Paget's disease is unclear, but some evidence suggests genetic and viral components 2.
Treatment of Paget's Disease
- Antiresorptive treatment with bisphosphonates is the standard treatment for Paget's disease 2, 3, 4.
- Zoledronic acid, a bisphosphonate administered as a single intravenous infusion, has been shown to be highly effective in treating Paget's disease, with a therapeutic response rate of 96% compared to 74% with oral risedronate 2, 5.
- Treatment with a potent bisphosphonate is indicated in patients with Paget's disease who have symptoms likely to respond to reduced bone turnover at pagetic sites, as well as in asymptomatic patients with active disease at sites susceptible to local progression and late complications 4.
- A single dose of 5 mg i.v. zoledronate is suggested as the treatment of choice in patients without contraindications 6.
Effects of Bisphosphonates on Paget's Disease
- Bisphosphonates restore normal bone turnover and relieve bone pain in patients with Paget's disease 2, 3.
- Zoledronic acid has been shown to improve bone pain in Paget's disease and is associated with a shorter median time to a first therapeutic response compared to risedronate 5.
- The effects of bisphosphonates on complications of Paget's disease, such as deformity, pathological fractures, and deafness, have not been adequately studied 3.
Monitoring and Follow-up of Paget's Disease
- Measurement of total ALP or other baseline disease activity markers at 6 to 12 weeks after treatment is an acceptable and cost-effective option for monitoring response to treatment 6.
- Biochemical follow-up is recommended to be used as a more objective indicator of relapse rather than symptoms, and the prolonged response after zoledronate treatment should be assessed every 1-2 years after normal bone turnover 6.