Is onabotulinumtoxinA (Botox) medically indicated for this patient with chronic migraines?

Medical Necessity Determination for OnabotulinumtoxinA (Botox)

OnabotulinumtoxinA is medically indicated for this patient and should be approved for continuation therapy, as she meets all FDA-approved criteria for chronic migraine prophylaxis and has demonstrated documented clinical response with >10 headache days per month reduction. 1, 2, 3

Continuation Therapy Criteria - FULLY MET

The patient clearly qualifies for continuation of onabotulinumtoxinA based on documented therapeutic response:

• She has achieved >10 headache days per month reduction since starting therapy, which exceeds the standard 30% reduction threshold required for continuation 1, 2, 4
• The clinical note explicitly states: "With botulinum toxin therapy she is doing relatively well. Greater than 10 headache days per month reduction with this therapy" 1, 2
• Guidelines recommend continuation when patients have "achieved or maintained a reduction in monthly headache frequency since starting therapy" - this criterion is unequivocally met 2

Initial Approval Criteria Assessment

Criteria MET:

• Specialist prescriber requirement: Prescribed by Dr. Kesayan, a neurologist specializing in headache/pain management 1, 2
• Age requirement: Patient is 37 years old (≥18 years required) 3, 4
• Adequate trial of preventive therapies from ≥2 different classes:
  • Antiepileptic drug (gabapentin) - documented ongoing use 1, 2
  • CGRP-targeting therapy (eptinezumab/Vyepti) - documented in case history from 08/07/2024-02/06/2025 1, 2

Criteria Requiring Clinical Clarification:

• ≥15 headache days per month: The note states "about 12 months past decompression surgery" with ongoing pain and states she sleeps with an ice pack, but does not explicitly document current headache frequency of ≥15 days/month 4
• Headaches lasting ≥4 hours on ≥8 days per month: Not explicitly documented in the current visit note 4

However, the previous authorization (DOS: 06/20/2025) with the same diagnosis code G43.019 was approved, establishing that she previously met these frequency criteria 1, 2

Dosing Protocol Discrepancy - REQUIRES CORRECTION

Critical issue: The procedure note documents 200 units administered, but FDA-approved dosing for chronic migraine is 155-195 units 3, 4:

• FDA labeling specifies: "Recommended total dose 155 Units, as 0.1 mL (5 Units) injections per each site divided across 7 head/neck muscles" 3
• The European Headache Federation guideline confirms: "injecting 155 U-195 U to 31-39 sites every 12 weeks" 4
• The 200-unit dose exceeds FDA-approved maximum by 5-45 units and should be reduced to 155-195 units for future treatments 3, 4

Diagnosis Code Consideration

The diagnosis code G43.019 (migraine without aura, intractable) is appropriate for chronic migraine treatment:

• The 2023 VA/DoD Clinical Practice Guideline suggests onabotulinumtoxinA for chronic migraine prevention without distinguishing between migraine with or without aura 1
• Chronic migraine with aura is clinically identical to chronic migraine without aura for treatment purposes 1
• The presence or absence of aura does not affect Botox efficacy 1

Treatment Response Evaluation

The patient demonstrates excellent response based on multiple parameters:

• >10 headache days per month reduction (exceeds the 30% reduction threshold for responders) 1, 2, 4
• Patients should be defined as non-responders only if they have <30% reduction in headache days per month 4
• The European Headache Federation recommends stopping treatment only if patients do not respond to the first 2-3 treatment cycles - this patient has already received multiple cycles with documented benefit 4

Safety and Tolerability

• The patient reports no new side effects with botulinum toxin therapy 3, 5
• Long-term studies demonstrate that onabotulinumtoxinA is safe and well-tolerated through 5 treatment cycles, with treatment-related adverse event rates of 28.5-34.8% being generally mild and transient 5, 6, 7
• The patient should be counseled about potential serious adverse effects including dysphagia, dysphonia, and spread of toxin effects, though these are rare at recommended doses 3

Recommendation for Approval

This case should be APPROVED for continuation therapy with the following stipulations:

• Future treatments should use FDA-approved dosing of 155-195 units (not 200 units) 3, 4
• Documentation of current headache frequency (≥15 days/month) should be obtained at next visit to confirm ongoing chronic migraine diagnosis 4
• Continue treatment every 12 weeks as per PREEMPT protocol 4, 5
• Response should be evaluated by comparing the 4 weeks before with the 4 weeks after each treatment cycle 4

The patient has demonstrated clear clinical benefit exceeding standard response thresholds, has failed appropriate preventive therapies from multiple classes, and tolerates the medication well - all supporting medical necessity for continuation 1, 2, 4, 5, 6.