migraine prophylaxis and botulinum toxin type A

Last reviewed 07/2021

NICE have issued guidance regarding the use of botulinum toxin in management of migraine (1).

NICE state that Botulinum toxin type A is recommended as an option for the prophylaxis of headaches in adults with chronic migraine (defined as headaches on at least 15 days per month of which at least 8 days are with migraine):

• that has not responded to at least three prior pharmacological prophylaxis therapies and whose condition is appropriately managed for medication overuse

When treatment with botulinum toxin type A that is recommended then it should be stopped in people whose condition:

• is not adequately responding to treatment (defined as less than a 30% reduction in headache days per month after two treatment cycles) or
• has changed to episodic migraine (defined as fewer than 15 headache days per month) for three consecutive months

Notes:

• Botulinum toxin type A is a purified neurotoxin complex, which is derived from the bacterium Clostridium botulinum
  • has neuromuscular transmitter blocking effects
  • has a UK marketing authorisation 'for the prophylaxis of headaches in adults with chronic migraine (headaches on at least 15 days per month of which at least 8 days are with migraine)'
  • recommended reconstituted dose is 155-195 units, administered intramuscularly as 0.1 ml (5 units) injections to between 31 and 39 sites around the head and back of the neck
  • recommended re-treatment schedule is every 12 weeks (see the summary of product characteristics)
• common adverse reactions include:
  • headache, migraine, facial paresis, eyelid ptosis, pruritus, rash, neck pain, myalgia, musculoskeletal pain, musculoskeletal stiffness, muscle spasms, muscle tightness, muscular weakness, and injection site pain
  • in general, adverse reactions occur within the first few days following injection and while generally transient, may have a duration of several months or, in rare cases, longer
  • for full details of adverse reactions and contraindications, see the summary of product characteristics

Reference:

• 1) NICE (June 2012). Botulinum toxin type A for the prevention of headaches in adults with chronic migraine.