What is the next step in managing a patient's headache that is relieved by paracetamol (acetaminophen) 600mg every 6 hours after a normal plain cranial computed tomography (CT) scan?

Management of Headache After Normal CT Scan and Relief with Paracetamol

For a patient with headache relieved by paracetamol 600mg every 6 hours after a normal cranial CT scan, the next step should be to upgrade to a more effective first-line treatment such as ibuprofen (400-600mg) or naproxen sodium (500-550mg) every 6 hours, as paracetamol alone is considered ineffective for migraine treatment. 1

Assessment of Headache Type

Based on the available information:

• Patient has headache that responded to paracetamol 600mg q6h
• CT scan was normal, ruling out serious intracranial pathology
• The current treatment is suboptimal as:
  • The dose of paracetamol (600mg) is below the recommended adult dose of 650mg 2
  • Paracetamol alone is considered ineffective for migraine treatment 1

Treatment Algorithm

Step 1: Optimize Acute Treatment

• Switch to NSAID therapy:

  • Ibuprofen 400-600mg every 6 hours (maximum 2.4g daily) 3, 1
  • OR Naproxen sodium 500-550mg every 6 hours (maximum 1.5g daily) 3, 1

• If NSAIDs are contraindicated (e.g., history of NSAID-induced asthma, bleeding disorders):

  • Continue paracetamol but optimize dosing to 650mg every 4-6 hours (not exceeding 4g daily) 2
  • Consider adding metoclopramide 10mg as adjunctive therapy 3

Step 2: For Inadequate Response to NSAIDs

• Add triptan therapy (if no contraindications such as cardiovascular disease):
  • Sumatriptan 50mg orally
  • OR Rizatriptan 10mg orally 1

Step 3: Preventive Therapy Consideration

• If headaches occur ≥2 times per month with significant disability
• OR if acute treatments are used more than twice weekly
• Consider preventive options:
  • Beta blockers (e.g., propranolol 80-240 mg/day)
  • Tricyclic antidepressants (e.g., amitriptyline 30-150 mg/day) 1

Patient Education

• Instruct patient to:

  • Maintain a headache diary to track frequency, severity, triggers, and response to treatment 1
  • Identify and avoid potential triggers (alcohol, caffeine, certain foods, stress, fatigue) 1
  • Implement non-pharmacological approaches:
    • Regular exercise
    • Consistent sleep schedule
    • Adequate hydration
    • Relaxation techniques 1

• Medication usage limits to prevent medication overuse headache:

  • NSAIDs: No more than 15 days per month
  • Paracetamol/OTC medications: No more than 14 days per month 1

Important Caveats

1. Paracetamol efficacy limitations: Research shows paracetamol 1000mg has an NNT of 12 for pain-free response at two hours, which is inferior to other commonly used analgesics 4. While it may be useful for tension-type headaches 5, 6, it is less effective for migraines.

2. Medication overuse risk: Limiting acute medication use is crucial to prevent medication overuse headache, which can develop with frequent use of analgesics 1.

3. Safety monitoring: Monitor for adverse effects of NSAIDs (GI upset, dizziness, rash) 3 and ensure paracetamol does not exceed maximum daily dose of 4g to prevent liver damage 2.

4. Combination therapy consideration: If single agents are ineffective, consider combination therapy with acetylsalicylic acid, acetaminophen, and caffeine, which has shown superior efficacy compared to monotherapy 7.