Changes in sodium valproate dispensing in women of childbearing age with a diagnosis of borderline personality disorder in Aotearoa New Zealand.

Aims: To compare sodium valproate dispensing in women of childbearing age diagnosed with borderline personality disorder in 2014 and 2019 to discover if prescribing practices in Aotearoa New Zealand have changed in response to international recommendations.

Methods: National dispensing data from the Pharmaceutical Collection were linked with diagnostic data from PRIMHD (the national mental health and addiction database) to identify people diagnosed with borderline personality disorder in Aotearoa New Zealand who were dispensed psychotropic medication. Dispensing of sodium valproate for women of childbearing age was compared between 2014 and 2019. Rates of dispensing were compared between ethnicities.

Results: In 2014, 10% of women of childbearing age diagnosed with borderline personality disorder were dispensed sodium valproate. This reduced to 6% of women in 2019 (p<0.001). In 2014, there was substantial ethnic disparity with 18.1% of Māori women and 15.8% of Pacific women dispensed sodium valproate compared with 7.4% of New Zealand Europeans. This disparity reduced in 2019, with 6.4% of Māori women and 12.5% of Pacific women dispensed sodium valproate compared with 5.6% of New Zealand Europeans.

Conclusions: These findings suggest that international recommendations and guidelines have been effective in changing clinical practice and reducing ethnic inequities. Given the significant risk to offspring exposed to sodium valproate, we echo warnings against off-label prescribing of sodium valproate in borderline personality disorder.