Syndrome of inappropriate antidiuretic hormone secretion associated with desvenlafaxine

Management of SIADH-related hyponatremia due to psychotropic medications - An expert consensus from the Association of Medicine and Psychiatry

OBJECTIVE

Hyponatremia is the most common electrolyte imbalance encountered in clinical practice and is associated with negative healthcare outcomes and cost. SIADH is thought to account for one third of all hyponatremia cases and is typically an insidious process. Psychotropic medications are commonly implicated in the etiology of drug induced SIADH. There is limited guidance for clinicians on management of psychotropic-induced SIADH.

METHODS

After an extensive review of the existing literature, clinical-educators from the Association of Medicine and Psychiatry developed expert consensus recommendations for management of psychotropic-induced SIADH. A risk score was proposed based on risk factors for SIADH to guide clinical decision-making.

RESULTS

SSRIs, SNRIs, antipsychotics, carbamazepine, and oxcarbazepine have moderate to high level of evidence demonstrating their association with SIADH. Evaluation for an avoidance of medications that cause hyponatremia is particularly important. Substitution with medication that is less likely to cause SIADH should be considered when appropriate. We propose an algorithmic approach to monitoring hyponatremia with SIADH and corresponding treatment depending on symptom severity.

CONCLUSIONS

The proposed algorithm can help clinicians in determining whether psychotropic medication should be stopped, reduced or substituted where SIADH is suspected with recommendations for sodium (Na+) monitoring. These recommendations preserve a role for clinical judgment in the management of hyponatremia with consideration of the risks and benefits, which may be particularly relevant for complex patients that present with medical and psychiatric comorbidities. Further studies are needed to determine whether baseline and serial Na+ monitoring reduces morbidity and mortality.

Desvenlafaxine in the treatment of major depression: an updated overview

Introduction: Major depressive disorder (MDD) remains one of the most prevalent mental health conditions. It is a chronic, relapsing condition and despite multiple treatment options, many patients fail to achieve remission of symptoms. Inadequacy of treatment has stimulated the search for agents with significant therapeutic advantages.Areas covered: This review examines literature concerning the use of desvenlafaxine in the treatment of MDD published since a previous analysis in this journal in 2014. Published papers were identified via a PubMed and Web of Science search and excluded congress presentations. Results from clinical trials in MDD, systematic reviews, and post hoc analyses in patient subgroups, are reviewed.Expert opinion: Desvenlafaxine was an effective antidepressant with favorable safety and tolerability in adults. Efficacy was demonstrated in the subgroup of peri- and post-menopausal women with MDD but not in children and adolescents. There is a relatively low potential for drug-drug interactions due to its metabolic profile. Hepatic impairment does not significantly alter dose requirements, whereas severe renal disease requires some adjustments of dose. Desvenlafaxine maybe suitable in patients with comorbid physical illnesses. Desvenlafaxine can be a first line consideration for the treatment of cases of MDD uncomplicated by medical comorbidities.

Association of Hyponatraemia and Antidepressant Drugs: A Pharmacovigilance-Pharmacodynamic Assessment Through an Analysis of the US Food and Drug Administration Adverse Event Reporting System (FAERS) Database

BACKGROUND

Hyponatraemia induced by antidepressant drugs is a rare but potentially life-threatening adverse reaction. Whether it is associated with all or only some antidepressant drugs is still unclear. This needs to be clarified to guide antidepressant therapies, especially in patients with electrolytic imbalances.

OBJECTIVES

The primary objective of this study was to quantify the strength of association between the use of different antidepressant drugs and hyponatraemia by using information reported to the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS). The secondary objective was to investigate the putative relationship between different antidepressant pharmacological targets and the risks of hyponatraemia induced by antidepressant drugs using the 'pharmacovigilance-pharmacodynamic' method.

METHODS

We used the FAERS database to conduct a case/non-case analysis on spontaneous reports, focusing on events of hyponatraemia/syndrome of inappropriate antidiuretic hormone secretion (SIADH) reported in connection with the use of antidepressant drugs. Risk was expressed as a measure of disproportionality using the reporting odds ratio while adjusting for sex, age and concomitant medications associated with hyponatraemia/SIADH. We assessed to what extent the receptor-binding properties of antidepressant drugs could associate with the reporting odds ratios of hyponatraemia/SIADH of antidepressant drugs, building a linear regression model that included as independent variables the binding affinities (pKi) to the serotonin transporter, dopamine transporter, norepinephrine transporter, and serotonin 5-HT_2C, 5-HT_2A and 5-HT_1A, and α₁- and α₂-adrenergic receptors.

RESULTS

There were 2233 reports identified. The adjusted reporting odds ratio for the association between antidepressant drug use and hyponatraemia was 1.91 (95% confidence interval 1.83-2.00). The association was strongest for mirtazapine, followed by selective serotonin reuptake inhibitors, and lowest with serotonin-modulating antidepressant drugs. A significant linear correlation was found between the adjusted reporting odds ratios for hyponatraemia and pKi for the adrenergic receptors α₁ and α₂.

CONCLUSIONS

Hyponatraemia is reported at a disproportionately higher level with classes of antidepressant drugs (noradrenergic and specific serotonergic antidepressant [mirtazapine] and serotonin modulators [vortioxetine]) that are in general considered to have a better profile of tolerability in terms of hyponatraemia. With regard to the presented results, the risk of hyponatraemia with mirtazapine appears to be greater than what was reported in the literature; however, confounding by indication cannot be ruled out. Our pharmacovigilance-pharmacodynamic analysis also indicates that inhibition of the serotonin transporter may not be involved in the hyponatraemia linked to the use of antidepressant drugs.