What is the treatment for giant cell arteritis?

Treatment of Giant Cell Arteritis

High-dose glucocorticoid therapy (40-60 mg/day prednisone) should be initiated immediately for induction of remission in active giant cell arteritis, with tocilizumab added as adjunctive therapy, especially in high-risk patients or those with cranial ischemic manifestations. 1

Initial Treatment Algorithm

1. Immediate Glucocorticoid Therapy:

   • Start prednisone 40-60 mg/day (1 mg/kg/day, maximum 60 mg/day) 2, 1
   • Maintain high-dose for one month before tapering 2
   • For patients with visual symptoms, consider IV methylprednisolone pulse therapy (250-1000 mg/day for 3 days) 1

2. Adjunctive Therapy:

   • Add tocilizumab 162mg subcutaneously weekly for: 1, 3
     • Patients at high risk for glucocorticoid-related adverse events
     • Refractory or relapsing disease
     • Presence of cranial ischemic manifestations
   • Methotrexate may be used as an alternative glucocorticoid-sparing agent 2, 1

Glucocorticoid Tapering Schedule

1. Initial Phase:

   • Maintain high-dose (40-60 mg/day) until symptoms resolve and inflammatory markers normalize 1
   • Taper to 15-20 mg/day within 2-3 months 1

2. Maintenance Phase:

   • Further taper to ≤5 mg/day after 1 year 1
   • Complete treatment typically requires about 2 years 1
   • Avoid alternate-day therapy as it increases relapse risk 2

Monitoring

• Regular clinical assessment for disease activity 1
• Monitor inflammatory markers (ESR, CRP) regularly 1
• Evaluate for visual deterioration and other ischemic complications 1
• Monitor for glucocorticoid and tocilizumab-related adverse effects 1, 3

Management of Relapses

1. For relapse with cranial ischemic symptoms:

   • Add or increase dose of non-glucocorticoid immunosuppressive agent (tocilizumab or methotrexate) 1
   • Increase glucocorticoid dose to 40-60 mg/day 1

2. For relapse with polymyalgia rheumatica symptoms only:

   • Increasing glucocorticoid dose alone may be sufficient 1

Important Clinical Considerations

• Temporal artery biopsy should be performed to confirm diagnosis but should not delay treatment initiation 2, 1
• Delaying glucocorticoid therapy when visual symptoms are present is the strongest risk factor for permanent blindness 1
• Visual loss is prevalent in 18% of patients at diagnosis and is usually irreversible 2
• Relapses are common during glucocorticoid tapering (34-75%) 1
• Most relapses occur at a median of 99 days after starting treatment 4

Pitfalls to Avoid

1. Delaying treatment while awaiting biopsy results - Treatment should be initiated immediately if GCA is suspected 1
2. Inadequate initial dosing - Underdosing may lead to increased risk of ischemic complications 2, 1
3. Tapering glucocorticoids too rapidly - Can lead to disease relapse 2, 1
4. Failing to add adjunctive therapy - Tocilizumab has been shown to be effective for refractory cases and reducing glucocorticoid exposure 2, 1, 3
5. Escalating therapy based solely on increased inflammatory markers - Clinical symptoms should guide treatment decisions 1
6. Failing to monitor for treatment-related adverse effects - Regular monitoring is essential to minimize complications 1, 3

The evidence strongly supports immediate high-dose glucocorticoid therapy with consideration of tocilizumab as adjunctive therapy, particularly in high-risk patients, to reduce the risk of ischemic complications and minimize glucocorticoid-related adverse effects.