The Canadian Headache Society (CHS) presented its updated migraine prophylaxis guideline at the World Congress of Neurology in Montreal late in 2023 and again at their inaugural conference this past October. This latest guideline includes important updates since the last guideline was published in 2012, notably with the inclusion of calcitonin gene-related peptide (CGRP) blocking agents and recommendations on prophylaxis strategies for Canadians living with chronic migraine. The updated guideline includes evidence-based recommendations for migraine prevention as well as practical treatment strategies based on expert consensus.
The migraine prophylaxis guideline is organized in two parts: one consisting of evidence-based recommendations and the second offering treatment strategies based on expert consensus. For the first part, a thorough review of the published literature using a rigorous systematic review protocol identified over 4,400 abstracts, from which 440 full papers were reviewed, and 63 studies were selected for inclusion. The quality of evidence was assessed using the GRADE system, and recommendations were obtained through consensus according to the Delphi method, with consensus defined as 70% agreement.
Updated Recommendations for Episodic Migraine Prophylaxis
A key update of the CHS guideline is the strong recommendation for CGRP blocking medications, both monoclonal antibodies and gepants, for prevention of episodic migraine (EM). This recommendation is based on moderate to high quality evidence for these agents.
CGRP blocking agents are strongly recommended for EM prophylaxis
Several other agents were added to the recommended list for EM prophylaxis, such as an NMDA receptor antagonist, a specific anticonvulsant, and an additional antihypertensive. However, these were all given a weak recommendation based on very low to moderate quality evidence. Two conventional oral agents were also downgraded to lower strength of recommendation.
Recommendations for Chronic Migraine Prophylaxis
Strongly recommended medications for prevention of chronic migraine (CM) include the CGRP blocking agents and botulinum neurotoxin, all based on high quality evidence, and beta-blockers based on moderate quality evidence.
The CHS updated guideline includes recommendations for prevention of CM for the first time
Migraine Prevention Strategies
From a practical perspective, the CHS updated guideline offers expert consensus on strategies for migraine prevention in specific circumstances: first time use, low side effect strategy, depression/anxiety, additional monotherapy strategies, and refractory patient strategy. Dr. Medrea called out an important change to the refractory EM patient strategy wherein CGRP monoclonal antibodies are very strongly recommended when first-line preventive treatments fail since their efficacy and safety are supported by the highest quality evidence. “This is an important advocacy piece because there are still patients who are being denied these treatments for episodic migraine,” said Dr. Medrea.
Furthermore, the CHS guideline committee included the CGRP blocking treatments and botulinum neurotoxin among the first-line preventive treatments for CM prophylaxis since these newer agents offer at least comparable efficacy as conventional oral agents and they have demonstrated a more favourable tolerability profile.
CGRP blocking agents and botulinum neurotoxin are recommended as first-line preventive treatments for chronic migraine
Dr. Medrea underscored the importance of shared decision-making between a clinician and their patient when selecting a migraine prophylaxis strategy, with consideration of individual factors such as tolerance to side effects, body mass index, hypertension, and patient preference.
Newer anti-CGRP medications have added to the arsenal of episodic and chronic migraine prevention
Our correspondent’s highlights from the symposium are meant as a fair representation of the scientific content presented. The views and opinions expressed on this page do not necessarily reflect those of Lundbeck.
