Postdoctoral Fellow The University of Manitoba Winnipeg, Canada
Background: Pregnant people with epilepsy (PPWE) are advised to continue antiseizure medications (ASMs) during pregnancy to minimize maternal and newborn adverse outcomes associated with seizures. With the availability of newer generation ASMs and the increased use of ASM for other indications - neuropathic pain and psychiatric disorders - a significant increase in utilization trends have been observed. Recent real-world data on ASMs utilization in pregnancy is essential.
Objectives: This study aimed to examine the trends of ASMs utilization among pregnant people in Canada.
Methods: This population-based utilization study included data from 3 Canadian provinces (Manitoba [MB], Saskatchewan [SK], and Alberta [AB]) between 1998 to 2019. We focused on ASMs used throughout the pregnancy, mono- vs poly-therapy, and different generations of ASMs. Epilepsy was defined through hospitalization and physician billings for epilepsy, during the 5 years prior to delivery. ASMs included old generations (phenytoin, carbamazepine and valproic acid) and new generation ASM (gabapentin and levetiracetam). We used descriptive analysis to calculate the patterns of ASMs use, and conducted subgroup analysis by socioeconomic status (higher vs. lower).
Results: We included 274,182, 245,899 and 533,402 people from MB, SK, and AB respectively. Epilepsy prevalence was 0.6% (1,759 cases) in MB, 0.7% (1,774 cases) in SK and 1% (5,048 cases) in AB. ASMs were used among 3,726 (1.4%), 1674 (0.6%), and 12,830 (2.4%) pregnancies in MB, SK and AB, respectively. Monotherapy was reported in 21.3%, 19.5% and 30.5% of PPWE, while polytherapy was reported in 24.4%, 5.2% and 11.7% in MB, SK and AB respectively. The combination of two first generation ASMs decreased from 97.7% to 44.2% in MB, 90.3% to 17.6% in SK and 58.73% to 39.11% in AB. The first-second generation combination increased from 0% to 10% in MB, 0% to 9.2% in SK, and 6.03% to 8.06% in AB, while the second-second generation combination increased from 0% to 45.8 % in MB, 9.7% to 73.2 % in SK and 35.2% to 52.8% for AB. The prevalence of utilization was 31.5%, 27.6%, and 12.6% among low SES, and 9.2%, 12.3%, and 28.4% among high SES in PPWE in MB, SK, AB respectively. In the group of pregnant people without epilepsy, gabapentin and clonazepam were the most commonly used ASM in MB and AB, while lamotrigine and gabapentin were the most commonly used in SK.
Conclusions: Our findings demonstrate that the use of old-generation ASMs during pregnancy is declining in Canadian populations, as recommended by guidelines, while the use of new-generation ASMs are rising. The growing trend in gabapentin use among pregnant people represents a potential concern.
