Pharmacological management of hyponatremia

ABSTRACT

Introduction: Hyponatremia is the most common electrolyte disorder with a prevalence of up to 30% in hospitalized patients. Furthermore, it is associated with increased morbidity and mortality.

Areas covered: This review discusses the efficacy and side effects of the currently available treatment options for hyponatremia and the differences in the pharmacological approach between the European and USA guidelines. Additionally, the authors provide their expert perspectives on current treatment strategies and what they expect from this field in the future.

Expert opinion: Several pharmacological options are available for the treatment of hyponatremia, but data from trials examining and comparing these treatments are missing. Regarding chronic hyponatremia, the role of vaptans should be further analyzed, focusing on comparisons with other active treatments on patient-relevant outcomes and not only on serum sodium concentration. Clinicians should be cautious to an overly rapid increase in serum sodium levels with all available treatment strategies. Finally, it is important to ascertain whether correction of serum sodium levels improves mortality in hyponatremic patients.

KEYWORDS:

• Hyponatremia
• vaptans
• urea
• demeclocycline
• loop diuretics
• saline

Article Highlights

• The intravenous administration of hypertonic saline is the treatment of choice for the management of acute or symptomatic hyponatremia.

• Restoration of plasma volume with isotonic saline is the treatment of choice in patients with hypovolemic hyponatremia but special attention should be given for a possible overcorrection when plasma volume is restored.

• Loop diuretics plus oral NaCl may be used as a second line therapy of chronic hyponatremia due to the syndrome of inappropriate antidiuresis (SIAD).

• Urea exerts beneficial effects on brain swelling and it is promising for the treatment of non-hypovolemic hyponatremia.

• Demeclocycline (900–1200 mg/d) induces nephrogenous diabetes insipidus and may be also used for chronic hyponatremia in association with water restriction.

• Vaptans significantly increase serum sodium levels compared with placebo, have been used in euvolemic and hypervolemic hyponatremia and their administration has been associated with improvements of symptoms in hyponatremic patients but not mortality.

• With the exception of vaptan trials, data from randomized controlled trials assessing and comparing the pharmacological options for hyponatremia treatment are missing.

This box summarizes key points contained in the article.

Declaration of interest

G Liamis has given lectures sponsored by various pharmaceutical companies including Bristol-Myers Squibb, Pfizer Inc, Eli Lilly and Company, Abbott, Amgen Inc, AstraZeneca, Novartis, Vianex, Teva Pharmaceuticals and Merck Sharp and Dohme. TD Filippatos has given lectures sponsored by Bristol-Myers Squibb, Pfizer Inc, Eli Lilly and Company, Abbott, Amgen, AstraZeneca, Novartis, Vianex, Teva Pharmaceuticals and Merck Sharp and Dohme. MS Elisaf has given lectures sponsored by AstraZeneca, Pfizer Inc, Abbott, Sanofi, Boehringer Ingelheim, Eli Lilly and Company and GlaxoSmithKline. He has also received grants for research protocols as well as given lectures sponsored by Merck Sharp and Dohme. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This manuscript has not been funded.