What is the recommended dosage and administration protocol for FDA-approved Botox (Botulinum Toxin) treatments for migraines?

FDA-Approved Botox Treatment Protocol for Chronic Migraine

For FDA-approved Botox treatment of chronic migraines, onabotulinumtoxinA should be administered at a dosage of 155-195 units injected across 31-39 specific sites in the head and neck region every 12 weeks, following the PREEMPT injection protocol. 1

Patient Eligibility Criteria

Botox (onabotulinumtoxinA) is FDA-approved specifically for chronic migraine, defined as:

• 15 or more headache days per month
• At least 8 of those days being migraine days
• Symptoms persisting for more than 3 months

Prior to Botox Treatment

Patients should typically have tried at least 2-3 other migraine preventive medications before starting Botox therapy 1. These may include:

• Beta-blockers (propranolol, timolol)
• Anticonvulsants (topiramate, valproate)
• Antidepressants (amitriptyline)
• CGRP antagonists

Administration Protocol

Dosage and Injection Sites

The FDA-approved protocol follows the PREEMPT injection paradigm:

• Total dose: 155-195 units
• Administered across 31-39 anatomical sites
• Divided across 7 specific muscle areas:
  1. Corrugator: 10 units (5 units each side)
  2. Procerus: 5 units
  3. Frontalis: 20 units (10 units each side)
  4. Temporalis: 40 units (20 units each side)
  5. Occipitalis: 30 units (15 units each side)
  6. Cervical paraspinal: 20 units (10 units each side)
  7. Trapezius: 30 units (15 units each side)

Administration Technique

• Use a sterile 30-gauge, 0.5-inch needle
• Dilute with preservative-free 0.9% sodium chloride
• Administer intramuscularly
• Standard dilution: 2 mL of diluent per 100-unit vial (resulting in 5 units/0.1 mL)
• Injections should be spaced approximately 1.5-2 cm apart

Treatment Schedule and Monitoring

• Treatments are administered every 12 weeks
• Evaluate response by comparing the 4 weeks before with the 4 weeks after each treatment cycle 1
• Response criteria: ≥30% reduction in headache days per month is considered a positive response 1
• Non-responders: Patients with <30% reduction after 2-3 treatment cycles should discontinue therapy

Contraindications and Precautions

• Known hypersensitivity to botulinum toxin
• Active infection at injection sites
• Pre-existing neuromuscular disorders
• Pregnancy and breastfeeding (safety not established)

Common Adverse Effects

• Neck pain (reported in approximately 9% of patients)
• Muscle weakness
• Headache
• Eyelid ptosis
• Facial paresis
• Injection site pain

Important Clinical Considerations

1. Medication overuse should ideally be addressed before starting Botox therapy, but treatment can be initiated concurrently with medication withdrawal if necessary 1

2. Treatment discontinuation should be considered when:

   • Patient achieves <10 headache days per month for 3 consecutive months
   • Patient shows no response after 2-3 treatment cycles

3. After discontinuation, patients should be re-evaluated 4-5 months later to ensure they have not reverted to chronic migraine 1

4. Botox is not recommended for episodic migraine (fewer than 15 headache days per month) 2, 3

5. The therapeutic effect typically begins within 1-2 weeks after injection and lasts approximately 12 weeks

By following this standardized protocol, healthcare providers can optimize the effectiveness of Botox treatment for chronic migraine patients while minimizing potential adverse effects.