A SINGLE CASE REPORT ON HYPERAMMONEMIA INDUCED BY VALPROATE MONOTHERAPY WITHOUT HEPATIC DYSFUNCTION

C Prarthana Saraswathi,S Nambi,J Anu Rita

doi:10.22159/ijpps.2017v9i4.8571

Abstract

Valproate is a commonly used mood stabilizer. One of the important and rare side effects of valproate is hyperammonemia leading to delirium and hepatic encephalopathy. Valproate-induced delirium is commonly mistaken for worsening of manic symptoms or psychosis. We hereby report a case of bipolar affective disorder who was on a therapeutic dose of valproate monotherapy developed altered mental status where we found elevated levels of plasma ammonia which decreased after the discontinuation of valproate and with normal levels of serum valproate, LFT’s, EEG and imagings. This case report emphasises on the need to consider plasma ammonia levels in patients with altered mental status receiving valproate in addition to other investigations.

Highlights

Valproate is a commonly used mood stabiliser and an anticonvulsant
We presented here the case of a valproate-induced delirium due to hyperammonemia in a patient with bipolar disorder when valproate dose was increased
A 58 y old male with the bipolar affective disorder was on a maintenance dose of valproate 500 mg per day past 3 mo and was increased to 1000 mg per day 4 d back. He presented with altered mental status, irrelevant and slurred speech, drowsiness, disorientation, difficulty in walking, altered sleep pattern and abdominal discomfort

Summary

INTRODUCTION

Valproate is a commonly used mood stabiliser and an anticonvulsant. Valproate-induced delirium due to hyper-ammonemia is a rare adverse effect ascribed to valproate. Valproate-induced hyperammonemia occurs when the patient is receiving additional medications like topiramate, has focal neurological deficits or has elevated liver function tests [1,2,3,4]. Such hyperammonemia occurs when valproate is initiated. A 58 y old male with the bipolar affective disorder was on a maintenance dose of valproate 500 mg per day past 3 mo and was increased to 1000 mg per day 4 d back He presented with altered mental status, irrelevant and slurred speech, drowsiness, disorientation, difficulty in walking, altered sleep pattern and abdominal discomfort. Repeat plasma ammonia was done on 5th day and it was decreased to 50 μmole/l

DISCUSSION

CONCLUSION