Is intravenous valproate more efficacious than oral valproate for inpatients with bipolar I disorder with a manic or depressive episode and concomitant symptoms of opposite polarity?

Intro Valproic acid (VPA) is a commonly prescribed mood stabilizer, available in both oral (OS) and intravenous (IV) formulations. However, few studies have compared their safety and efficacy. This retrospective study aimed to investigate the safety and efficacy of and IV-VPA in patients with Bipolar Disorder.Methods Fifty patients with Bipolar Disorder experiencing a manic or depressive episode, with concomitant symptoms of opposite polarity, admitted to our inpatient unit and treated with IV-VPA were included in a retrospective, single-centre, non-randomized, open-label, parallel-group comparative study. Fifty patients experiencing a manic or depressive episode, with concomitant symptoms of opposite polarity, treated with oral-VPA and selected among those who were admitted to the inpatient unit prior to the introduction of IV-VPA in our clinical practice, were included as the control group (matched based on age, gender and clinical scales score at baseline). The Clinical Global Impression (CGI), Young Mania Rating Scale (YMRS), Montgomery-Asberg Depression Rating Scale (MADRS) and Hamilton Anxiety Rating Scale (HAM-A) scores were recorded at baseline, after 3 days of treatment and discharge from the inpatient unit. Patients were asked to respond on the basis of the symptoms present on the day the scale was administered. Response rate and the presence of adverse effects were also recorded.Results Both patients treated with oral and IV-VPA demonstrated significant improvements in all psychometric scales (p < 0.001). However, the IV group exhibited superior efficacy, with significantly lower scores on the CGI, YMRS, MADRS and HAM-A scales on Day 3 and at discharge from the inpatient unit. The IV-VPA treatment showed higher response rates on all psychometric scales, and no adverse effects were reported in either group.Conclusion This retrospective study supports the use of IV-VPA as a more efficacious treatment option for patients with Bipolar Disorder, particularly in acute settings where rapid symptom improvement is crucial. Both oral and IV-VPA were found to be safe and well-tolerated.