Headache Medicine

ISSN 2178-7468

-ISSN 2763-6178

v.11

Supplement

p. 42

October 2020.

ASAA

DOI: 10.48208/HeadacheMed.2020.Supplement.42

Peres, M.; Swerts, D.

Headache Medicine

Placebo effect in chronic migraine prevention. A systematic review

Diego Swerts, Mario Peres

FISCAE

Background

The preventive management of headaches has different routes of administration (Oral, Subcutaneous, Intravenous, and Application to the

head). Placebo effect is a powerful determinant of health outcomes in several disorders, Meta-analysis of clinical trials in pain conditions

such as bromyalgia and osteoarthritis shows placebo effect can contribute to up to 75% of the overall treatment effect. The placebo

effect on different routes of administration is poorly described. Thus, we seek to analyze in this meta-analysis the difference between the

routes of administration in the placebo effect in the management of chronic migraine.

Methods

We conducted a meta-analysis with 8 randomized , double blind, Placebo Clinical trials, with 2498 persons. Men and Women over 18

who suffer from chronic migraine (over 15 migraine episodes per month for 3 months) without associated comorbidities. We compared

those who received placeboadministered agent for preventive treatment of chronic migraine SC, EV or oral against those who received

placebo-administered head injection. The primary outcome was reduction in the number of days with migraine in the month assessed at

12 weeks of treatment compared with baseline.

Results

Our study showed that placebo responses were greater when botulinum toxin type A was applied in the head, followed by intravenous

injection of an anti-CGRP monoclonal antibody eptinezumab. Oral topiramate and subcutaneous Mabs had no difference, being inferior

to other routes of administration. Also, our analysis shows that much of the effect of drugs in the treatment of migraine is still due to the

high placebo effect, which contributes about 80% of the therapeutic gain.

Conclusions

Administration route affects placebo responses in CM preventive treatment but not therapeutic gain as much. Elucidating the underlying

mechanisms that mediate placebo effect in migraine treatment is benecial to clinical practice and drug development.

Keywords:

Chronic migraine, Placebo effect, Randomized clinical trials