What is the best approach for managing headaches in a male patient with a history of an accident, currently experiencing right-side headaches, and taking duloxetine, who is requesting gabapentin and has declined other treatment options such as physical therapy and NSAIDs?

Management of Post-Traumatic Headache in a Patient Requesting Gabapentin

Direct Recommendation

Do not prescribe gabapentin for this patient's post-traumatic headaches, as there is insufficient evidence supporting its efficacy for migraine prophylaxis, and the patient has not yet tried evidence-based first-line treatments. 1, 2

Evidence-Based Treatment Algorithm

Step 1: Establish Appropriate Acute Treatment

Since the patient declined NSAIDs and is experiencing right-sided headaches following trauma, the most appropriate next step is:

• Initiate a triptan (sumatriptan 50-100 mg, rizatriptan, or naratriptan) for acute headache episodes, as triptans are first-line therapy for moderate to severe migraine attacks and have strong evidence for efficacy 1, 3
• The patient should take the triptan as early as possible when headache begins while pain is still mild to maximize effectiveness 1, 3
• Strictly limit triptan use to no more than 2 days per week (10 days per month) to prevent medication-overuse headache 1, 3

Step 2: Optimize Current Duloxetine Regimen

The patient is already on duloxetine, which has some evidence for headache prevention:

• Consider increasing duloxetine dose if currently below therapeutic range, as the patient declined splitting to BID dosing 1
• Duloxetine may provide modest benefit for mixed headache patterns, though evidence is stronger for amitriptyline in migraine with tension-type features 1

Step 3: Add Evidence-Based Preventive Therapy

If headaches occur more than 2 days per week or produce significant disability, preventive therapy is indicated:

• First-line preventive options include:
  • Propranolol 80-240 mg/day (strongest evidence, most consistent efficacy) 1, 3
  • Topiramate (good evidence, though may cause cognitive side effects) 1, 3
  • Amitriptyline 30-150 mg/day (particularly if mixed migraine and tension-type features) 1, 3

Step 4: Why Gabapentin Should NOT Be Used

Gabapentin lacks sufficient evidence for migraine prophylaxis:

• A Cochrane systematic review of 1,009 patients found gabapentin is NOT efficacious for episodic migraine prophylaxis 2
• Pooled analysis showed no significant difference between gabapentin (1800-2400 mg) and placebo for headache frequency reduction (MD -0.44; 95% CI -1.43 to 0.56) 2
• Gabapentin is NOT recommended for routine clinical practice due to lack of efficacy and high adverse event rates 2
• Common adverse effects include dizziness (17% vs 7% placebo), somnolence (19% vs 9% placebo), and ataxia (13% vs 6% placebo) 4, 2
• Gabapentin causes significant driving impairment and CNS depression, which would impact quality of life 4

Limited evidence exists only for:

• Individual case reports of cluster headache (not applicable to this patient) 5
• One positive study showing modest benefit, but contradicted by larger systematic review 6, 2

Critical Clinical Pitfalls to Avoid

Medication-Overuse Headache Prevention

• Any acute headache medication used more than 2 days per week can cause medication-overuse headache, leading to daily headaches and treatment resistance 1, 3
• Triptans trigger medication-overuse headache at ≥10 days per month, NSAIDs at ≥15 days per month 1, 3
• If the patient is already using acute medications frequently, initiate preventive therapy immediately rather than adding another acute treatment 3

Red Flags Requiring Further Evaluation

Given the history of trauma, assess for:

• Progressive worsening of headache pattern (suggests structural lesion) 7
• Headache awakening patient from sleep (concerning for increased intracranial pressure) 7
• Neurologic examination abnormalities (requires neuroimaging) 7

Addressing Patient's Treatment Refusals

The patient has declined multiple evidence-based options:

• Reconsider NSAIDs: Naproxen 500-825 mg has strong evidence as first-line therapy and can be combined with triptans for enhanced efficacy 1, 3
• Physical therapy: While declined, lifestyle modifications including regular aerobic exercise, consistent sleep schedule, adequate hydration, and stress management should be strongly encouraged as these have evidence for migraine reduction 1, 3
• Splitting duloxetine to BID: This may improve headache control through more stable drug levels, though evidence is limited 1

Practical Implementation

Immediate prescription:

• Sumatriptan 50-100 mg tablets, take 1 tablet at headache onset (maximum 2 doses per 24 hours, separated by at least 2 hours) 3
• Dispense limited quantity (e.g., 9 tablets) to enforce frequency limits 3

If headaches occur ≥2 days per week after 4 weeks:

• Add propranolol 80 mg daily, titrate to 160-240 mg daily over 2-4 weeks 1, 3
• Continue triptan for breakthrough headaches, maintaining <2 days per week usage 3

Contraindications to assess before prescribing triptans:

• Ischemic heart disease, previous myocardial infarction, uncontrolled hypertension, cerebrovascular disease, or peripheral vascular disease 3

If triptans are contraindicated or ineffective:

• Consider CGRP antagonists (gepants): rimegepant, ubrogepant, or zavegepant as second-line alternatives 1, 3
• These have no vasoconstriction and are safe in cardiovascular disease 3