Oxcarbazepine (OXC) is an antiepileptic drug used as a mood stabilizer in patients diagnosed with bipolar disorder (BD). OXC has been reported as a source of hyponatremia in its use in both epilepsy and BD.

We present the case of a 53 year-old male patient diagnosed with Schizoaffective disorder, bipolar type who developed hyponatremia during his treatment with OXC.

The patient’s treatment was desvelafaxine 100 mg, Paliperidone depot 150 mg, Oxcarbazepine 600 mg which he had maintained for at least one year. He began to manifest headache, asthenia and mild confusion gradually, with morning predominance, without being clearly suggestive of an acute worsening.

In control analysis, the existence of sodium leveles of 127 and low osmolarity was observed. Therefore it was decided to suspend furosemide, close monitoring of water intake in order to rule out primary polydipsia and extra salt was introduced into the diet. Given the persistence of the symptoms, laboratory abnormalities and ruled out the existence of primary polydipsia, it was decided to suspend treatment with oxcarbazepine. After the discontinuation of the aforementioned drug the analytical findings went back to normal ranges and the symptoms disappeared.

Carrying out control tests in patients with psychiatric pathology and multiple psychiatric treatments is essential to be able to rule out analytical alterations which could be asymptomatic or with nonspecific symptoms that could be attributed to the underlying pathology. The easy reversal of symptoms encourages us to emphasize the study and differential diagnosis of each case.

No significant relationships.

Oxcarbazepine (OXC) is an antiepileptic drug widely used in the treatment of bipolar disorder (BD), specially when there are side effects with other mood stabilizers. Nevertheless, it isn’t innocuous of adverse effects and its consequences can even endanger the patient’s life.

Brief review of the literature on OXC-induced hyponatremia and exposure of a case report.

Review of the literature through research in the PubMed database, using the following keywords: “oxcarbazepine”, “hyponatremia” and “adverse effects”.

Although most of the patients are asymptomatic, hyponatremia is one of the most important side effects of OXC. About 29.9% of the patients develop hyponatremia, but only 2.5-3% of psychiatric patients develop severe hyponatremia. The risk of hyponatremia is higher during the first three months of treatment. Severe and/or symptomatic hyponatremia has important clinical implications and may be associated with neurological damage, including seizures, brain stem herniation and death. A 44-year-old woman diagnosed with BD started OXC due to drug intoxications with other mood stabilizers. Six days after initiating treatment, she presented persistent vomiting and severe hyponatremia was detected in blood tests. OXC was suspended with symptomatic resolution.

Healthcare professionals should be alert to symptoms that may arise in patients under OXC. Periodic evaluations of serum sodium levels should be carried out. Cases of severe and/or symptomatic hyponatremia should be rapidly identified and treated in order to reduce the risk of developing brain injury and death.

To investigate whether measurement of plasma levels can predict tolerance to oxcarbazepine (OXC).

We reviewed medical records to identify all inpatients consecutively treated by OXC at the University Department of Psychiatry in Bordeaux. Adverse effects were rated before treatment onset, at day 3, then every week and at discharge or at discontinuation. Residual hydroxy-OXC concentrations were measured on blood samples at the same periods.

OXC was prescribed to 20 patients with bipolar (n = 18) or schizoaffective bipolar-type disorder (n = 2). Reported side effects were transient and occurred mostly at the beginning of the treatment. Three patients stopped OXC because of severe cutaneous side effects. Residual hydroxy-OXC plasma levels were similar in patients with or without occurrence of side effects at all times of assessment.

Our data suggest that the occurrence of severe side-effects is relatively high with OXC. Measurement of plasma OXC levels does not appear to be of interest in clinical practice since plasma concentrations are not predictive of the occurrence of side effects.

This study compared the efficacy and safety of oxcarbazepine and divalproex sodium in acute mania patients.

In this 12 week, randomized, double-blind pilot study, 60 patients diagnosed with acute mania (DSM-IV) and a baseline Young Mania Rating Scale (YMRS) score of 20 or more received flexibly dosed oxcarbazepine (1000–2400 mg/day) or divalproex (750–2000 mg/day). The mean decrease in the YMRS score from baseline was used as the main outcome measure of response to treatment. A priori protocol-defined threshold scores were ≤12 for remission and ≥15 for relapse. Number of patients showing adequate response and the time taken to achieve improvement was compared. Adverse events were systematically recorded throughout the study.

Over 12 weeks, mean improvement in YMRS scores was comparable for both the groups including the mean total scores as well as percentage fall from baseline. There were no significant differences between treatments in the rates of symptomatic mania remission (90% in divalproex and 80% in oxcarbazepine group) and subsequent relapse. Median time taken to symptomatic remission was 56 days in divalproex group while it was 70 days in the oxcarbazepine group (p = 0.123). A significantly greater number of patients in divalproex group experienced one or more adverse drug events as compared to patients in the oxcarbazepine group (66.7% versus 30%, p < 0.01).

Oxcarbazepine demonstrated comparable efficacy to divalproex sodium in the management of acute mania. Also the overall adverse event profile was found to be superior for oxcarbazepine.