Valproate in acute mania: is our practice evidence based?

Abstract

This audit was conducted on acute psychiatric in-patient wards with the aim of establishing if valproate prescribing in acute mania followed evidence-based guidelines with particular emphasis on formulations used and whether accelerated valproate dosing was employed. Case notes from 43 (42 percent male) patients admitted with mania and subsequently discharged on valproate were reviewed. Valproate formulation, weight measurement (necessary for dose-calculation in accelerated dosing), initial valproate dose and increments, serum valproate monitoring and other prescribed psychotropic agents were noted. Most (95 percent) patients received sodium valproate (epilim chrono/generic), the remaining received valproate semi-sodium (depakote). All but one patient received antipsychotic medication in combination. Weight was recorded in only four (9 percent) patients. The mean valproate daily dose after the first week was 1,027mg (sd = 408). It took 29 (sd = 42) days to reach the maximum daily dose (1,426 mg sd = 467) from valproate initiation. Serum levels were monitored in 34 (79 percent) cases, but the mean period between valproate initiation to the first serum level test was 38 (sd = 47) days. A significant positive correlation was found between days taken to reach maximum dose and hospital stay (Spearman's rho = 0.41, n = 43, p = 0.006, two-tailed). Accelerated valproate dosing was not common practice, which may have resulted in suboptimal efficacy, probably leading to combination treatment. This study highlights the need for adequate initial dosing and dose increments when treating manic patients and suggests current practice is not evidence-based. Local prescribing policy and national guidelines' influence on practice are discussed.