OnabotulinumtoxinA (Botox) injections provide relief for some people with chronic headaches and might be a viable option for people who do not tolerate daily medication well. Botox would most likely be considered if the headaches have features of chronic migraines.
It is an injection of a neurotoxin derived from the bacteria that causes botulism. When the Botox botulinum toxin is purified and used in tiny doses in specific areas, it temporarily reduces muscle contractions for approximately 3 months.
Botox is injected around pain fibers that are involved in headaches. Botox enters the nerve endings around where it is injected and blocks the release of chemicals involved in pain transmission. This prevents activation of pain networks in the brain.
Botox prevents migraine headaches before they start, but takes time to work. One treatment lasts for 10-12 weeks, and two Botox treatments may reduce the number of headache days by approximately 50%.
The FDA approves the use of Botox to treat chronic migraine in adults who are age 18 or over. Botox is considered an “off-label” treatment if it’s used for children or adolescents.
The most common side effect from the Botox shots is a sore neck, and using an ice pack may reduce the discomfort. It can take up to six months to see the maximum benefit from Botox. In the meantime, the patient can continue his regular headache medications with no risk of a drug interaction.