Is medical necessity met for Botox (Botulinum toxin) 155 units intramuscularly (IM) every 12 weeks and procedure code 64615 x3 for a patient with a diagnosis of Chronic migraine without aura, intractable, with status migrainosus (G43.711) and Headache, unspecified (R51.9)?

Medical Necessity Assessment for Botox 155 Units IM Every 12 Weeks

Medical necessity is likely met for onabotulinumtoxinA (Botox) 155 units IM every 12 weeks with procedure code 64615 x3 for this patient with chronic intractable migraine, provided the patient has failed at least 2-3 oral preventive medications from different classes and meets complete ICHD-3 diagnostic criteria. 1

Critical Prerequisites for Medical Necessity

Required Prior Medication Trials

• The patient must have documented failure of 2-3 oral preventive medications from different classes before onabotulinumtoxinA is considered medically necessary. 1, 2
• Acceptable medication classes include:
  • Antidepressants (amitriptyline, venlafaxine, escitalopram) 1
  • Beta-blockers (propranolol, metoprolol, atenolol) 1
  • Anticonvulsants (topiramate, valproate) 1
• Each trial must be documented for at least 60 days at therapeutic doses, with clear documentation of start/stop dates and reason for discontinuation or failure 1
• If the patient is currently on Emgality (a CGRP antagonist), this counts as one adequate trial, but additional trials from different classes are necessary 1

Diagnostic Criteria Documentation

• Complete ICHD-3 diagnostic criteria must be documented, including at least 2 of the following pain characteristics: 1
  • Unilateral location
  • Pulsating quality
  • Moderate-to-severe intensity
  • Aggravation by routine physical activity
• The patient must have ≥15 headache days per month for >3 months, with migraine features present on ≥8 days per month 3, 1
• A formal 28-day headache diary may be required to comprehensively document headache frequency, migraine features, and associated symptoms (nausea, vomiting, photophobia, phonophobia) 1

Medication Overuse Consideration

• If the patient is taking multiple acute medications (such as alprazolam and ibuprofen 600mg), this represents a risk factor for medication overuse headache. 1
• The European Headache Federation recommends withdrawal from overused medication before initiating onabotulinumtoxinA if feasible 2
• However, if withdrawal is not feasible, onabotulinumtoxinA can be initiated from the start or before withdrawal, particularly given the intractable nature and status migrainosus presentation 1, 2

FDA-Approved Dosing and Administration

• The FDA-approved dose is 155 units every 12 weeks, administered according to the PREEMPT injection protocol (155-195 units to 31-39 sites). 1, 2
• The procedure code 64615 x3 is appropriate for the multiple injection sites required by the PREEMPT protocol 1
• OnabotulinumtoxinA is the only FDA-approved therapy specifically for chronic migraine prophylaxis 1

Evidence of Efficacy

• High-quality evidence from the PREEMPT trials demonstrates that onabotulinumtoxinA reduces headache days by 1.9 days per month in chronic migraine populations (95% CI -2.7 to -1.0) 4
• The treatment showed a significant reduction of -8.4 days with onabotulinumtoxinA versus -6.6 days with placebo at 24 weeks 1
• Improvements in headache symptoms, functioning, and quality of life are seen regardless of medication overuse status and whether patients are naive to prophylactic therapy 5

Common Pitfalls to Avoid

• Inadequate documentation of prior medication trials is the most common reason for denial—ensure each trial has documented duration, dose, and reason for failure 1
• Incomplete ICHD-3 criteria documentation—all required pain characteristics and frequency criteria must be explicitly documented 1
• Missing headache diary documentation—a 28-day diary provides objective evidence of headache frequency and characteristics 1
• The diagnosis code R51.9 (Headache, unspecified) is redundant when G43.711 (Chronic migraine without aura, intractable, with status migrainosus) is documented, as the latter is more specific 6

Treatment Response Evaluation

• Patients should be defined as non-responders if they have less than 30% reduction in headache days per month during treatment 2
• Treatment should be stopped if the patient does not respond to the first 2-3 treatment cycles 2
• Response should be evaluated by comparing the 4 weeks before with the 4 weeks after each treatment cycle 2

Safety Profile

• Treatment-related adverse events occur in approximately 60/100 participants versus 47/100 with placebo (RR 1.28,95% CI 1.12 to 1.47) 4
• Common adverse events include neck pain, facial paresis, and eyelid ptosis, consistent with injection into head and neck muscles 5
• The treatment is generally well tolerated with no CNS side effects, organic damage, or allergic complications reported 7