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Briefing note: botulinum toxin type a (Botox)

SMC did not accept botulinum toxin type A 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).

  • A migraine is a severe, painful headache that is often preceded or accompanied by flashes of light, blind spots, tingling in the arms and legs, nausea, vomiting, and increased sensitivity to light and sound. The pain can last for hours or even days. Migraine results from enlargement of blood vessels and the release of chemicals from nerve fibres surrounding these blood vessels.
  • Botulinum toxin type A can prevent headaches associated with migraine. It works by paralysing the muscles of the head and neck that trigger migraines. It can be injected into superficial muscles (under the skin) and deep muscles of the head and neck. The medicine should always be administered by appropriate trained staff in specialist centres.
  • Studies have shown that people given botulinum toxin type A had a greater reduction in the number of days on which they experienced a headache compared with people given placebo (a dummy medicine containing no active treatment). However, there was no comparison of botulinum toxin type A with other medicines used to prevent headaches associated with chronic migraine.
  • The safety profile of botulinum toxin type A is well known and the incidence of side effects of concern is low.
  • SMC did not accept botulinum toxin type A for the prevention of headaches associated with migraine because there were a number of weaknesses in the clinical and economic data prepared by the manufacturer which meant it did not offer value for money.