Antiseizure Medication Dispensing Before and After Initiation of Antidementia Medicines: A Population-Based Matched Cohort Study.
4 affiliations
- 1Institute for Health Research, University of Notre Dame, Fremantle, Western Australia, Australia.
- 2Medical School, University of Western Australia, Perth, Western Australia, Australia.
- 3School of Population and Global Health, University of Western Australia, Perth, Western Australia, Australia.
- 4La Trobe Rural Health School, La Trobe University, Bendigo, Victoria, Australia.
Abstract
Purpose
Seizures and behavioural and psychiatric features may prompt antiseizure medication (ASM) use in dementia. We examined whether increased ASM dispensing precedes or follows initiation of antidementia treatment to inform hypotheses about when these indications emerge.Methods
Using the Australian Pharmaceutical Benefits Scheme (PBS) 10% sample, we matched people aged ≥ 50 years with incident antidementia dispensing in 2018-2021 1:1 to controls without antidementia dispensing (2013-2024) by age, sex, index year and diabetes and hypertension treatment. We compared annual ASM dispensing (ATC N03, excluding gabapentinoids) from 5 years before to 3 years after initiation using McNemar's test and interrupted time series analysis. Sensitivity analyses re-matched on Rx-Risk comorbidity and removed the survival requirement.Results
Among 4385 matched pairs (59.8% women; mean age 78.3 years), ASM dispensing was higher in cases 5 years before initiation (2.7% vs. 1.8%; ratio 1.53, 95% CI = 1.15-2.03) and the difference widened after initiation (year 3: 9.1% vs. 2.4%; ratio 3.85, 95% CI = 3.13-4.75). Valproate accounted for most of the excess (year 3 ratio 6.97, 95% CI = 4.80-10.12). Levetiracetam dispensing rose gradually from year -3 and was higher after initiation (year 3 ratio 2.30, 95% CI = 1.51-3.50). Matching on comorbidity attenuated pre-initiation differences (year -5 ratio 1.42). The excess was greater at ages 50-79 years.Conclusions
ASM dispensing, most noticeably valproate, was higher in people with antidementia medicine dispensing than in controls, modestly before and markedly after initiation. Behavioural and psychiatric indications seem to predominate, with a smaller seizure-related contribution possibly beginning before treatment, although dispensing data cannot confirm indications. Valproate use warrants review.
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BibTeX
@article{almeida2026antiseizure,
title = {{Antiseizure Medication Dispensing Before and After Initiation of Antidementia Medicines: A Population-Based Matched Cohort Study.}},
author = {Osvaldo P Almeida and Christopher Etherton-Beer and Frank M Sanfilippo and David B Preen and Amy Page},
journal = {Pharmacoepidemiology and drug safety},
year = {2026},
month = nov,
doi = {10.1002/pds.70530},
url = {https://europepmc.org/article/MED/43010636},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Antiseizure Medication Dispensing Before and After Initiation of Antidementia Medicines: A Population-Based Matched Cohort Study.
AU - Osvaldo P Almeida
AU - Christopher Etherton-Beer
AU - Frank M Sanfilippo
AU - David B Preen
AU - Amy Page
PY - 2026
DA - 2026/11/01
JO - Pharmacoepidemiology and drug safety
DO - 10.1002/pds.70530
UR - https://europepmc.org/article/MED/43010636
AB - Purpose Seizures and behavioural and psychiatric features may prompt antiseizure medication (ASM) use in dementia. We examined whether increased ASM dispensing precedes or follows initiation of antidementia treatment to inform hypotheses about when these indications emerge.Methods Using the Australian Pharmaceutical Benefits Scheme (PBS) 10% sample, we matched people aged ≥ 50 years with incident antidementia dispensing in 2018-2021 1:1 to controls without antidementia dispensing (2013-2024) by age, sex, index year and diabetes and hypertension treatment. We compared annual ASM dispensing (ATC N03, excluding gabapentinoids) from 5 years before to 3 years after initiation using McNemar's test and interrupted time series analysis. Sensitivity analyses re-matched on Rx-Risk comorbidity and removed the survival requirement.Results Among 4385 matched pairs (59.8% women; mean age 78.3 years), ASM dispensing was higher in cases 5 years before initiation (2.7% vs. 1.8%; ratio 1.53, 95% CI = 1.15-2.03) and the difference widened after initiation (year 3: 9.1% vs. 2.4%; ratio 3.85, 95% CI = 3.13-4.75). Valproate accounted for most of the excess (year 3 ratio 6.97, 95% CI = 4.80-10.12). Levetiracetam dispensing rose gradually from year -3 and was higher after initiation (year 3 ratio 2.30, 95% CI = 1.51-3.50). Matching on comorbidity attenuated pre-initiation differences (year -5 ratio 1.42). The excess was greater at ages 50-79 years.Conclusions ASM dispensing, most noticeably valproate, was higher in people with antidementia medicine dispensing than in controls, modestly before and markedly after initiation. Behavioural and psychiatric indications seem to predominate, with a smaller seizure-related contribution possibly beginning before treatment, although dispensing data cannot confirm indications. Valproate use warrants review.
SN - 1053-8569
SN - 1099-1557
ER -