Treatment of Giant Cell Arteritis
Immediate initiation of high-dose glucocorticoids is the cornerstone of treatment for giant cell arteritis (GCA) to prevent irreversible complications such as permanent vision loss.
Initial Treatment
For GCA with Visual or Neurologic Symptoms (Emergency Treatment)
- Start intravenous methylprednisolone 250-1000 mg/day for 3 days 1, 2
- Follow with high-dose oral prednisone (40-60 mg/day or 1 mg/kg/day, maximum 60 mg) 2
For GCA without Visual or Neurologic Symptoms
- Immediately start oral prednisone 40-60 mg/day (1 mg/kg/day, maximum 60 mg) 2
- Maintain high-dose therapy for one month before beginning taper 2
Diagnostic Considerations
- Temporal artery biopsy should be performed to confirm diagnosis but should not delay treatment initiation 2
- Biopsy should be performed within 2 weeks of starting steroids 2
- Noninvasive vascular imaging (CT angiography, MR angiography, or ultrasound) should be ordered to evaluate large vessel involvement 2
Adjunctive Therapy
Tocilizumab
- Tocilizumab (162mg subcutaneously weekly) is recommended as adjunctive therapy, especially in high-risk patients or those with cranial ischemic manifestations 2, 3
- FDA-approved for treatment of GCA 3
- Helps reduce glucocorticoid exposure and prevent relapses 2
Other Adjunctive Options
- Methotrexate may be used as a glucocorticoid-sparing agent 2
- Aspirin should be considered for patients with critical involvement of vertebral or carotid arteries 2
Glucocorticoid Tapering
- After 1 month of high-dose therapy, begin gradual taper 2
- Aim for 15-20 mg/day within 2-3 months 2
- Further taper to ≤5 mg/day after 1 year 2
- Complete treatment typically requires about 2 years 2
- Avoid alternate-day therapy as it increases relapse risk 2, 4
Monitoring
- Regular clinical assessment for disease activity and treatment-related adverse effects 2
- Monitor inflammatory markers (ESR, CRP) regularly 2
- Watch for relapses during glucocorticoid tapering (34-75% relapse rate) 2
Important Considerations
- Delaying glucocorticoid therapy when visual symptoms are present is the strongest risk factor for permanent blindness 2
- Inadequate initial dosing may lead to increased risk of ischemic complications 2
- Tapering glucocorticoids too rapidly can lead to disease relapse 2
- Calcium, vitamin D, and peptic ulcer prophylaxis should accompany steroid therapy 5
Management of Relapses
- For GCA recurrence, restart prednisone at 40-60 mg/day 2
- Decision between 40 mg versus 60 mg based on:
- Severity of symptoms
- Previous response to treatment
- Presence of visual symptoms
- Risk of glucocorticoid-related adverse events 2
By following this treatment approach, the risk of permanent vision loss and other ischemic complications can be significantly reduced, while minimizing the adverse effects of long-term glucocorticoid therapy.