Post-Authorization Safety Study to Assess the Effectiveness of the Newly Implemented Risk Minimization Measures for Topiramate: Drug Utilization Study

Study type

• Study topic:
  Human medicinal product
• Study type:
  Non-interventional study
• Scope of the study:
  Assessment of risk minimisation measure implementation or effectiveness

  Drug utilisation
• Data collection methods:
  Secondary use of data

Non-interventional study

• Non-interventional study design:
  Cohort

Study drug and medical condition

• Study drug International non-proprietary name (INN) or common name:
  TOPIRAMATE
• Anatomical Therapeutic Chemical (ATC) code:
  (N03AX11) topiramate

  topiramate
• Medical condition to be studied:
  Epilepsy

  Migraine

Population studied

• Short description of the study population:
  Patients in this study will be WOCBP (≥13 to ≤49 years of age and without prior record of hysterectomy or sterilization) identified in the healthcare database selected for each of the countries (France, Germany, Spain, Sweden, UK). ; Depending on the study objective, patients must have epilepsy and/or migraine or be exposed to topiramate.
• Age groups:
  Adolescents (12 to < 18 years)

  Adults (18 to < 46 years)

  Adults (46 to < 65 years)
• Special population of interest:
  Women of childbearing potential not using contraception

  Women of childbearing potential using contraception

Study design details

• Study design:
  The study design is a pre-post, observational study using data from existing healthcare databases in the EU and the UK. ; The pre- and post-implementation periods will be defined as 36 months prior to publication of Bjørk et al. on 31 May 2022 and 36 months after implementation of the new RMMs.
• Main study objective:
  The overarching goal of the study is to describe the use of topiramate among WOCBP with epilepsy or migraine during pre- and post-implementation periods of the newly implemented RMM and to determine the effectiveness of the newly implemented RMMs to reduce exposure to topiramate during pregnancy and for at least up to four weeks after discontinuing treatment with topiramate.
• Outcomes:
  Exposure to topiramate is the outcome of interest and will be determined by indication. In addition, new users of topiramate during the pre- and post-implementation periods will be characterized by indication.
• Data analysis plan:
  The data from each data source will be analysed separately according to a common study protocol. ; All descriptive analyses will be displayed for the pre- and post-implementation periods, overall and by age category and country. ; Interrupted time-series analysis is planned for primary objective 1, contingent upon sufficient statistical power. All other study objectives are descriptive. ; Continuous variables will be summarized using appropriate statistics for continuous variables (eg, mean, standard deviation (SD), median, range, minimum and maximum). ; Categorical variables will be summarized using appropriate statistics (eg, number, percentage and 95% Clopper-Pearson confidence intervals).