Ammonemia in bipolar patients on maintenance treatment with valproic acid

Psychotropic Medication of Acute Episodes of Mood Disorders: Current Prescription Attitude in Two Psychiatric Wards in Cagliari, Italy

Background:

Medication of acute episodes of mood disorders has changed over the last decades following the results of randomized clinical trials.

Objective:

The aim of this study was to analyze medication prescribed at discharge from two psychiatric wards. We focused on hospitalization as one of the best opportunities to start prophylaxis.

Methods:

We examined retrospectively the clinical records of 357 patients hospitalized for mood episodes in two psychiatric wards in the Cagliari area (SPDC-1 and SPDC-2) between 1 January and 31 December 2016. We focused on the psychotropic medication prescribed at discharge from the hospital.

Results:

Most patients were discharged with antipsychotics (86%) and/or benzodiazepines (89%). Combined medication was frequent, including various co-administration of first-generation and/or second-generation antipsychotics (26% of patients), or antipsychotics combined with mood-stabilizers (51% of patients). There was a preferential prescription of first-generation antipsychotics in SPDC-1, and of second-generation antipsychotics in SPDC-2. Prescription of lithium was significantly more frequent in SPDC-1.

Conclusion:

Although the treatment was in line with randomized clinical trials, the choice of individual psychotropic agents differed significantly between the two wards. Different prescription attitudes can have consequences on the long-term outcome of patients discharged from the hospital after an acute mood episode.

Levocarnitine for valproate-induced hyperammonemia in the psychiatric setting: A case series and literature review

Introduction

Hyperammonemia is a potential adverse effect of valproic acid (VPA) therapy, which is often asymptomatic but can lead to severe, life-threatening encephalopathy. Carnitine deficiency due to VPA is the proposed mechanism for hyperammonemia and the development of VPA-induced hyperammonemic encephalopathy (VHE). Levocarnitine, the active form of carnitine, has been suggested for treatment and prevention of VHE.

Methods

Data was collected by chart review of 3 patients who received oral levocarnitine supplementation in the psychiatric setting for VPA-induced hyperammonemia. Review of the literature was performed through June 2017 using the following PubMed search terms: valproate, valproic acid, hyperammonemia, altered mental status, encephalopathy, and levocarnitine. Articles were included if they described use of levocarnitine in VPA-treated patients with psychiatric disorders.

Results

One patient developed encephalopathy with resolution of symptoms after VPA discontinuation. Valproic acid was restarted with the addition of levocarnitine to prevent VHE reoccurrence. In the other 2 cases, levocarnitine was started prophylactically in patients who developed hyperammonemia without emergence of any clinical symptoms. Ammonia levels were reduced to normal in all cases, and no symptoms consistent with encephalopathy were reported. The literature search identified 6 additional cases with 5 of 6 reports supporting use of levocarnitine for decreased ammonia levels as well as an observational trial.

Discussion

This literature review and case series illustrates successful use of levocarnitine supplementation for reduction of ammonia levels in the setting of VPA-induced hyperammonemia among patients with psychiatric disorders. However, clinical significance of ammonia reduction in asymptomatic patients is difficult to determine.

Adverse drug reactions induced by valproic acid

Valproic acid is a widely-used first-generation antiepileptic drug, prescribed predominantly in epilepsy and psychiatric disorders. VPA has good efficacy and pharmacoeconomic profiles, as well as a relatively favorable safety profile. However, adverse drug reactions have been reported in relation with valproic acid use, either as monotherapy or polytherapy with other antiepileptic drugs or antipsychotic drugs. This systematic review discusses valproic acid adverse drug reactions, in terms of hepatotoxicity, mitochondrial toxicity, hyperammonemic encephalopathy, hypersensitivity syndrome reactions, neurological toxicity, metabolic and endocrine adverse events, and teratogenicity.