Understanding and Responding to Prescribing Patterns of Sodium Valproate-Containing Medicines in Pregnant Women and Women of Childbearing Age in Western Cape, South Africa

INTRODUCTION: Growing evidence of the teratogenic potential of sodium valproate (VPA) has changed prescribing practices across the globe; however, the impact of this research and the consequent dissemination of a Dear Health Care Professional Letter (DHCPL) in December 2015, recommending avoidance of the teratogen VPA in women of childbearing age (WOCBA) and pregnant women in South Africa, is unknown. We explored trends and reasons for VPA use among pregnant women and WOCBA in the public sector in Western Cape Province from 1 January 2015 to 31 December 2017. METHODS: Using the provincial health information exchange that collates routine electronic health data via unique patient identifiers, we analysed clinical and pharmacy records from 2015 to 2017 to determine prescription patterns of VPA and other antiepileptic drug (AED) and mood-stabilising medicine (MSM) use in WOCBA and pregnant women. Senior clinicians and policy makers were consulted to understand the determinants of VPA use. RESULTS: At least one VPA prescription was dispensed to between 8205 (0.79%) and 9425 (0.94%) WOBCA from a cohort of approximately 1 million WOCBA attending provincial health care facilities per year. Prescriptions were more likely in HIV-infected women compared with HIV-uninfected women (1.1–1.3% vs. 0.7–0.9%; p < 0.001). VPA use in WOCBA remained stable at 0.8–0.9% over the review period despite the 2016 DHCPL. VPA was the most prescribed AED/MSM, constituting 43.2–45.5% of all WOCBA taking at least one such agent, while lamotrigine, the other recommended first-line agent, was only prescribed in 7.8–8.9% of WOCBA. Over 3 years, approximately 663 pregnancies were exposed to VPA, with a steady rise in the number of exposures each year (n = 204, 214 and 245, respectively). CONCLUSION: Despite warnings, VPA remained the most frequently prescribed AED or MSM in WOCBA. Contributing factors are described. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40264-020-00987-4) contains supplementary material, which is available to authorized users.