Prevalence and risk factors for hyponatremia in adult epilepsy patients: Large-scale cross-sectional cohort study.

Abstract

PURPOSE:

To evaluate the risk factors and prevalence of hyponatremia among epilepsy patients in relation to use of antiepileptic drugs (AEDs).

METHODS:

We retrospectively reviewed 14,620 adult patients (aged 18-103 years) and classified them into the following 3 groups: patients without AED treatment (n = 2165, Group I), patients receiving antiepileptic drugs other than carbamazepine (n = 7442, Group II), and patients treated with carbamazepine (n = 5013, Group III). This study did not include the patients receiving oxcarbazepine or eslicarbazepine acetate because these AEDs are not marketed in Japan. Severe hyponatremia was defined as a serum sodium level < 130 mEq/L.

RESULTS:

In Groups I, II, and III, the mean sodium level was 140, 139, and 137 mEq/L, respectively. The highest frequency of severe hyponatremia was observed in Group III (7%), and it was much higher than in Group I (0.8%) or Group II (1.2%). In Groups II and III, old age, low body weight, and concomitant use of phenobarbital, benzodiazepines, or antipsychotics were risk factors for hyponatremia. In Group III, the sodium level decreased as the carbamazepine dose increased. At a carbamazepine dose exceeding 600 mg/day, there was 10.9-fold higher prevalence of hyponatremia, and the risk was potentiated by concomitant use of valproate.

CONCLUSION:

The serum sodium level should be monitored carefully when patients are receiving AED polypharmacy combined with antipsychotics. In particular, concomitant administration of valproate enhances the risk of hyperammonemia in patients receiving carbamazepine. These findings may help clinicians to avoid hyponatremia in patients with epilepsy.

• Authors: Yoshiaki Yamamoto, Yukitoshi Takahashi, Katsumi Imai, Akiko Ohta, Yoshiyuki Kagawa, Yushi Inoue
• Journal: Seizure (Seizure) Vol. 73 Pg. 26-30 (Dec 2019) ISSN: 1532-2688 [Electronic] England
• PMID: 31707295 (Publication Type: Journal Article)
• Copyright: Copyright © 2019. Published by Elsevier Ltd.

Chemical References

• Anticonvulsants
• Antipsychotic Agents
• Benzodiazepines
• Carbamazepine
• Valproic Acid

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Anticonvulsants (administration & dosage, adverse effects)
• Antipsychotic Agents (administration & dosage, adverse effects)
• Benzodiazepines (administration & dosage, adverse effects)
• Carbamazepine (administration & dosage, adverse effects)
• Cohort Studies
• Cross-Sectional Studies
• Drug Therapy, Combination (adverse effects)
• Epilepsy (complications, drug therapy)
• Female
• Humans
• Hyponatremia (chemically induced)
• Male
• Middle Aged
• Prevalence
• Retrospective Studies
• Risk Factors
• Valproic Acid
• Young Adult