Drug Safety https://doi.org/10.1007/s40264-020-00987-4 ORIGINAL RESEARCH ARTICLE Understanding and Responding to Prescribing Patterns of Sodium Valproate‑Containing Medicines in Pregnant Women and Women of Childbearing Age in Western Cape, South Africa Ushma Mehta1 · Mariette Smith1,2 · Emma Kalk1 · Helen Hayes3 · Annoesjka Swart4 · Lawrence Tucker5 · Renier Coetzee6 · Andrew Boulle1,2 · Marc Blockman7 © The Author(s) 2020 Abstract 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 identifers, 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 clini- cians 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 frst-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 fac- tors are described. 1 Introduction (WOCBA; unless there is no other efective treatment avail- able) due to convincing evidence of high rates of congenital In recent years, the Medicines Control Council in South malformations (approximately 11%) [3] and neurodevel- Africa (MCC; now known as the South African Health Prod- opmental impairment (30–40%) such as delayed physical ucts Regulatory Authority [SAHPRA]), the US Food and milestones, memory problems, difculties in speech and lan- Drug Administration (FDA) [1], the European Medicines guage, and lower intellectual ability associated with in utero Agency (EMA) [2] and other regulatory authorities have exposure [4–11]. In addition, there is compelling evidence highlighted the need to completely avoid sodium valproate of an increased risk of autism and autism spectrum disorder (VPA) in pregnant women and women of childbearing age in children exposed to VPA in utero [12–15]. Due to its poor safety profle in pregnancy, VPA is indi- cated for epilepsy only in WOCBA who are intolerant of Electronic supplementary material The online version of this article (https ://doi.org/10.1007/s4026 4-020-00987 -4) contains or unresponsive to other antiepileptic treatments and who supplementary material, which is available to authorized users. are compliant with an efective Pregnancy Prevention Pro- gramme (PPP) [2]. However, in HIV-infected adults in * Ushma Mehta South Africa receiving antiretroviral treatment (ART), VPA [email protected] has been one of two therapeutic options recommended as Extended author information available on the last page of the article Vol.:(0123456789) U. Mehta et al. through key informant interviews and meetings with senior Key Points clinicians and policy makers at the provincial level. Despite warnings, valproate use in women of childbear- ing age (WOCBA) has not changed in the Western Cape 2 Methods Province of South Africa over a 3-year period, and sodium valproate (VPA) remains the most commonly We conducted a retrospective review of aggregate popula- prescribed antiepileptic or mood-stabilising medicine tion-level data. The Provincial Health Data Centre (PHDC) among women of childbearing age in the Western Cape in the Western Cape is a health information exchange in Province of South Africa. which all electronic health data are linked via a unique Over 3 years, approximately 663 pregnancies were patient identifer allocated to all patients seeking care at exposed to VPA, with a steady rise in the num- public health facilities in the Western Cape Province [17]. ber of exposures each year (n = 204, 214 and 245, Anonymised, aggregate data extracts were provided by respectively). Contributing factors to these trends are the PDHC for a cohort of WOCBA (13–55 years of age) described, including the concerns about drug–drug inter- over 3 years from January 2015 to December 2017. Preg- actions between antiepileptic/mood-stabilising medicines nancies were identifed electronically through a series of and antiretrovirals. evidences implying pregnancy, categorised by various lev- els of confdence. These evidences included registration on Despite signifcant measures that have been taken at MomConnect (a mobile health messaging service for South both a national and provincial level, the implementa- African mothers); laboratory tests (e.g. rhesus test, preg- tion of new approaches to the treatment of epilepsy in nancy test, syphilis test, Beta HCG test, and pap smear with women are hindered by challenges facing clinicians in a recorded gestational age); outcome-related evidences (e.g. resource-limited setting with a high burden of HIV. birth registration, diagnostic/procedure-related codes indi- cating a pregnancy outcome, maternal death, maternal dis- charge summary); electronic admission records for antenatal and obstetric ward visits; and the use of pregnancy-related frst-line treatment for the management of epilepsy, the other medicines (e.g. misoprostol and mifepristone in combina- being lamotrigine [16]. This is primarily because most other tion indicating termination of pregnancy, iron and folate dis- antiepileptics have clinically signifcant drug–drug interac- pensed) [17–19]. Only high-confdence pregnancies were tions with ART, afecting the safety and efcacy of both included in this analysis. antiepileptic and antiretroviral agents. VPA is also indi- Antiepileptic drug/mood-stabilising medication (AED/ cated for maintenance therapy for bipolar mood disorder, MSM) use was identifed from electronic pharmacy dis- and, together with lithium, was until recently considered a pensing records and linked to women in the cohort via the frst-line option in the public sector in South Africa [16]. It unique patient identifer. We defned a pre- and intra-preg- has also been used for migraine prophylaxis, although VPA- nancy period, which starts at the beginning of the calendar containing products are not registered for this indication in year before the year of delivery and ends with delivery. VPA South Africa [1]. exposure during pregnancy was defned as a WOCBA with Prior to this study, valproate prescribing practices in evidence of pregnancy who has at least one prescription of South Africa were undocumented. In December 2015, a VPA dispensed during the pregnancy period. The pregnancy Dear Health Care Professional Letter (DHCPL) was dissemi- period was defned as the estimated pregnancy start date nated to registered medical practitioners and pharmacists to the pregnancy outcome (including pregnancy loss) date. in South Africa warning about the high risk of congenital Where available, the last menstrual period and reported ges- anomalies and developmental disorders associated with VPA tational age based on ultrasound were used to estimate the use during pregnancy (See Electronic Supplementary Mate- pregnancy period. In the absence of this data, a period of rial 1). This study aimed to establish whether this regulatory 280 days prior to birth was considered the pregnancy period safety alert had any impact on clinical care or prescribing. for a full-term birth. To ensure maximal ascertainment of We aimed to assess the extent of VPA use among pregnant exposure, all women identifed as being prescribed valproate women and WOCBA seeking care in the public sector in the in pregnancy were included in our analyses even if the preg- Western Cape Province, South Africa, using linked popula- nancy outcome was unknown. tion-level electronic clinical and pharmacy records between We explicitly decomposed VPA exposures during preg- January 2015 and December 2017, i.e. 1 year before and nancy into three types, by timing: (1) VPA initiated dur- 2 years after the December 2015 DHCPL safety alert. We ing pregnancy (defned as the frst recorded prescription of explored reasons for ongoing VPA use in the public sector VPA issued during the pregnancy period); (2) VPA switched Valproate Prescribing Trends in Pregnant Women and Women of Childbearing Age for an alternative during the course of the pregnancy (frst course of the study period (Table 1). Over the 3 years, at AED/MS prescription without VPA issued after the esti- least one VPA prescription was dispensed to between 0.79% mated pregnancy start date and before the pregnancy out- and 0.94% of these WOCBA . In all 3 years, prescriptions come date); and (3) VPA used throughout pregnancy. Data for VPA were signifcantly more likely in HIV-infected on pregnancy exposures were confned to sites where the WOCBA and pregnant women compared with HIV-negative pharmacy electronic management system was present for women or women for whom HIV status was undocumented more than 3 months prior to onset of the pregnancy, reduc- (p < 0.001) (Table 1). VPA prescriptions for WOCBP or ing the likelihood of a false date of treatment onset in rela- pregnant women did not signifcantly decrease after the tion to the pregnancy episode.