While the PREEMPT protocol provides recommendations on the proper use of onabotulinumtoxinA (BoNT-A) for migraine prevention, there is a wide variety in methods of injection between clinicians and for the same clinician based on patient needs, according to study results published in Headache.
BoNT-A is one of the Food and Drug Administration (FDA)-approved treatments for migraine prevention and was shown to decrease the number of headache days. The FDA approved the 155-unit fixed dose, fixed-site PREEMPT protocol of BoNT-A injections for migraine 9 years ago. However, over time many modifications of the original protocol were developed to improve patient management and/or comfort.
The goal of the current study was to explore alterations in PREEMPT protocol and the explanations for them using an anonymous questionnaire to headache clinicians. The surveys were sent by email via Redcap on November 8th, 2019 with 3 weekly automatic reminders. The survey link was closed on December 13th, 2019. Everyone received the same survey with the questions asked in the same order.
The survey was emailed to 878 Headache Medicine clinicians, of which 182 (20.7%) completed the survey, including 11 (6%) with <1 year of experience with BoNT-A injection for chronic migraine, 40 (22%) that had between 1 and 3 years of experience, and 130 (71.4%) with ≥3 years of experience.
Out of the 182 responders, 141 (77.5%) did not always follow the PREEMPT protocol and alterations included modification of the number of injections (128 participants, 70.3%), the total units of BoNT-A injected (115 participants, 63.2%), sites injected (105 participants, 57.7%), dilution (22 participants, 12.1%), and addition of lidocaine (4 participants, 2.2%). Furthermore, there were some variations in checking for blood return before injecting.
The main reported reasons for changes in number, dose, and location of injections included adapting to the patients’ pain, anatomy, and preferences.
The study had several limitations, according to the researchers, including difficulties to identify all the headache specialists in North America, missing data on their level of training, and that that the survey was designed to stop if participants answered that they always followed the PREEMPT protocol.
“The wide inter- and intra-personal variations in BoNT-A injections for chronic migraine prevention seen in this survey raise concerns about the standardization of the procedure and suggest that an advisory protocol containing more evidence and discussion of the reasoning behind the recommendations might be more helpful than the current prescriptive protocol,” conclude the researchers.
Begasse de Dhaem O, Gharedaghi MH, Rizzoli P. Modifications to the PREEMPT protocol for onabotulinumtoxinA injections for chronic migraine in clinical practice. Headache. doi:10.1111/head.13823