Prescription for Suspected Giant Cell Arteritis (GCA)

Important note: GCA is a medical emergency. Do NOT delay treatment to await biopsy results. Irreversible vision loss can occur within hours to days. Start corticosteroids immediately when clinical suspicion is high.

Scenario A: GCA Suspected - No Visual Symptoms

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PRESCRIPTION
Patient: _______________  DOB: ___________  Date: ___________
Clinician: _____________  Signature: _______________________
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Rx 1:
  Prednisolone 5 mg tablets
  Dose: 60 mg (12 tablets) orally, once daily in the morning
  Duration: 2-4 weeks at this dose, then taper as below
  Quantity: 200 tablets

Tapering Schedule (guided by symptoms + ESR/CRP):
  - Weeks 1-4:    60 mg/day (induction)
  - Weeks 5-8:    50 mg/day (reduce by 10 mg)
  - Weeks 9-12:   40 mg/day (reduce by 10 mg)
  - Weeks 13-16:  30 mg/day (reduce by 10 mg)
  - Weeks 17-20:  20 mg/day (reduce by 10 mg)
  - Weeks 21-24:  15 mg/day (reduce by 5 mg)
  - Weeks 25-28:  10 mg/day (reduce by 5 mg)
  - Thereafter:   Reduce by 1 mg every 4-6 weeks until lowest
                  effective maintenance dose (caution below 10 mg/day)
  Total course: typically 12-24 months
  
  ⚠ Do NOT use alternate-day dosing — higher failure rates

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Rx 2:
  Aspirin 75-100 mg tablets
  Dose: 75 mg orally, once daily with food
  Duration: Ongoing (unless contraindicated)
  Quantity: 90 tablets
  Note: Antiplatelet therapy to reduce risk of ischaemic events

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Rx 3 (Steroid Protection):
  Omeprazole 20 mg capsules
  Dose: 20 mg orally, once daily
  Duration: For the duration of corticosteroid therapy
  Quantity: 60 capsules
  Note: Gastric protection while on long-term steroids

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Rx 4 (Bone Protection):
  Calcium 500 mg + Vitamin D3 400 IU tablets
  Dose: 1 tablet orally, twice daily
  Duration: For the duration of corticosteroid therapy
  Quantity: 120 tablets

  PLUS consider:
  Alendronic acid 70 mg tablets (if ≥40 years, post-menopausal
  women, or FRAX score indicates high fracture risk)
  Dose: 70 mg orally, once weekly on an empty stomach
  Quantity: 12 tablets (3-month supply)
  Note: Bisphosphonate for steroid-induced osteoporosis prevention

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Scenario B: GCA with Acute Visual Symptoms (Amaurosis Fugax or Vision Loss)

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INPATIENT ORDERS

IV Methylprednisolone (Solu-Medrol):
  Dose: 500 mg - 1000 mg IV once daily
  Duration: 3 days
  Then: transition to oral prednisolone 60-80 mg/day
  (followed by gradual taper as in Scenario A)

Aspirin 300 mg orally, stat loading dose, then 75 mg daily

Urgent ophthalmology and rheumatology referral

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Scenario C: Adding Tocilizumab (Biologics - Steroid-Sparing, FDA-Approved)

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Rx:
  Tocilizumab (Actemra) 162 mg/0.9 mL pre-filled syringe
  Dose: 162 mg subcutaneously, ONCE WEEKLY
  Combined with: rapid prednisolone taper to zero by month 6
  Duration: 52 weeks (per GiACTA trial protocol)
  
  Monitoring required:
  - LFTs and lipid profile at baseline, 4-8 weeks, then 3-monthly
  - Neutrophil count at baseline and each visit
  - Note: CRP and ESR will be suppressed by tocilizumab — 
    cannot use these to monitor disease activity
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Concurrent Orders and Monitoring

Key Clinical Points

• Age cutoff: GCA almost exclusively affects patients aged >50 years (mean onset ~72 years)
• ACR/EULAR 2022 criteria for classification include: new-onset headache, jaw claudication, sudden visual loss, tender/thickened temporal artery, markedly elevated ESR (>50 mm/hr) or CRP
• Biopsy: Obtain a segment 3-5 cm with serial sections. A negative biopsy does NOT exclude GCA (skip lesions occur) - if clinical suspicion is high, continue treatment
• Response to steroids is usually dramatic within 24-48 hours; failure to improve within 5-7 days should prompt reconsideration of the diagnosis
• Relapse: If relapse occurs during taper, increase prednisone by 5-10 mg; for frank visual threat, repeat IV methylprednisolone
• Duration: GCA is typically self-limited over 1-2 years; most patients can discontinue steroids, but some require low-dose maintenance for years
• Tocilizumab (anti-IL-6 receptor mAb) is approved in the US as initial combination therapy with prednisone. It allows a faster taper and reduces cumulative steroid dose (GiACTA RCT, 2017)

• Harrison's Principles of Internal Medicine, 22nd ed. (2025), p. GCA Treatment section
• Goldman-Cecil Medicine, International Edition, Treatment section on GCA
• Firestein & Kelley's Textbook of Rheumatology: "Early treatment of GCA can prevent blindness. GCA requires an initial dose of prednisone of approximately 60 mg/day"
• Kanski's Clinical Ophthalmology, 10th ed., p. 787 (GCA treatment)
• Textbook of Family Medicine, 9th ed., p. 2442 (GCA taper protocol)
• Fuster and Hurst's The Heart, 15th ed., p. Giant Cell Arteritis section
• Biologic therapies for large vessel vasculitis: systematic review (2025) - PMID 40063878
• Turkish Society Rheumatology GCA guidelines (2026) - PMID 41930660