(93) Trends of Antiseizure Medications Utilization in Pregnant People: Population-Level Data from Two Canadian Provinces Over Two Decades

Friday, August 26, 2022

8:00 AM – 6:00 PM CEST

Location: Hall C

Publication Number: 424

Presenting Author(s)

Sherif Eltonsy, PhD
– Assistant Professor, University of Manitoba, University of Manitoba, Winnipeg, Manitoba, Canada

Co-Author(s)

Payam Peymani, PharmD
– Postdoctoral Fellow, The University of Manitoba, Winnipeg, Manitoba, Canada
Brandace Winquist
– Adjunct Professor, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada., Cabri, SK, Canada
Joseph Delaney, PhD
– Associate Professor, College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
Walid Shouman
– University of Manitoba, Winnipeg, MB, Canada
Alekhya Lavu
– The University of Manitoba, University of Manitoba, Winnipeg, Manitoba, Canada
Kaarina Kowalec
– Assistant Professor, College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, MB, Canada
Marcus Ng
– Max Rady College of Medicine, Internal Medicine, Section of Neurology, University of Manitoba, MB, Canada

Background: Several antiseizure medications (ASMs) have established evidence of fetal risk with in-utero exposure. Studies in Canada and other countries have shown an increase in the utilization of ASMs; however, little is known about the trends of newer ASMs, especially in pregnant people.

Objectives: We examined the time-trends of the utilization of different ASMs among pregnant people in two Canadian provinces over 20 years.

Methods: A retrospective population-based cohort study was conducted using data from the province of Manitoba (MB) and Saskatchewan (SK) Canada. We constructed a cohort of all pregnant women from 1998 to 2019, using the provincial administrative health databases. We examined ASMs in classes (i.e., generations), regimens (mono/polytherapy), and separately.

Results: We included 274,182 and 245,899 women in 2 cohorts from MB and SK respectively. From MB, 1,759 (0.6%) pregnant people had epilepsy diagnosis and 3726 (1.36%) pregnant people were exposed to ASMs, with or without epilepsy. In SK, 1774 (0.7%) pregnant people had an epilepsy diagnosis, and 1674 (0.6%) pregnant people were exposed to ASMs with or without epilepsy. In MB, carbamazepine and phenytoin were the most dispensed ASM among pregnancies with epilepsy between 1998 and 2019, while lamotrigine became the most dispensed ASM among pregnant people with epilepsy by 2019. In SK, carbamazepine and lamotrigine were the most dispensed ASM among pregnancies with epilepsy. Among pregnant people without epilepsy, clonazepam and gabapentin were the most dispensed ASM in MB, while gabapentin and lamotrigine were the most dispensed in SK. In regimens analysis, monotherapy was presented in 37.4 % and 19.5 % of pregnant people with epilepsy in MB and SK respectively, while polytherapy was present in 7.4% and 0.8 % in MB and SK respectively. We observed an increasing trend in the new-generation ASMs polytherapy in both provinces throughout the study period (1998-2019). The combination of first-first generation ASMs dropped from 97.7% to 44.2% in MB and 90.3 to 17.6%, in SK. Combination of the first-second generation increased from 0 to 10% in MB and 0 to 9.2% in SK, while combinations of second-second generation increased from 0 to 45.8 % in MB and 9.7 to 73.2 % in SK.

Conclusions: First-generation ASMs use during pregnancy seems to show a decreasing trend in Canadian populations, as opposed to new-generation ASMs which are on the rise. It is essential to evaluate the neonatal safety profile of new-generation ASMs, especially those with scarce safety evidence. Future studies on ASMs utilization during pregnancy in other populations are warranted.