Hyponatremia associated with bupropion

Pharmacological Approach to Smoking Cessation: An Updated Review for Daily Clinical Practice

Tobacco use is one of the major public health concerns and it is the most preventable cause of morbidity and mortality worldwide. Smoking cessation reduces subsequent cardiovascular events and mortality. Smoking is a real chronic disorder characterized by the development of an addiction status mainly due to nicotine. This condition makes the smokers generally unable to quit smoking without help. Different strategies are available to treat smoking dependence that include both non-pharmacological (behavioral counselling) and pharmacological therapies. Currently, it is well accepted that smoking cessation drugs are effective and safe in real-world settings. Nicotine replacement therapy (NRT), varenicline, bupropion and cytisine are the main pharmacological strategies available for smoking cessation. Their efficacy and safety have been proved even in patients with chronic cardiovascular disease. Each of these drugs has peculiar characteristics and the clinician should customize the smoking cessation strategy based on currently available scientific evidence and patient's preference, paying particular attention to those patients having specific cardiovascular and psychiatric comorbidities. The present document aims to summarize the current viable pharmacological strategies for smoking cessation, also discussing the controversial issue regarding the use of alternative tobacco products, in order to provide useful practical indications to all physicians, mainly to those involved in cardiovascular prevention.

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.

Bupropion Induced Hyponatremia in an Elderly Patient: A Case Report and Review of the Literature

We present the case of a 72-year-old female with a major depressive episode who developed hyponatremia associated with bupropion. In reviewing the literature, there are only a few case reports which pertain to this topic. The clinical symptoms of hyponatremia can be misinterpreted as a worsening of the primary psychiatric illness and can lead to potentially serious consequences if not fully evaluated. We recommend that clinicians should be well aware of this side effect and that sodium levels should be checked within the first 2 weeks after initiating treatment in patients, especially those with additional risk factors for hyponatremia, such as older age, female sex, diuretic use, low BMI, and unexplained mental status changes at any time during treatment with antidepressants. The risk for hyponatremia associated with mirtazapine appears to be low and its use can be helpful in patients who have developed hyponatremia induced by other antidepressants and who experienced symptoms of weight loss and insomnia.

Hyponatraemia and confusion in a 70-year-old female when bupropion was added to dothiepin and escitalopram

OBJECTIVE

Hyponatraemia secondary to syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a well-recorded adverse event observed in elderly patients on antidepressant treatment. Bupropion is an antidepressant agent usually reserved as an augmentation strategy for treatment-resistant depression. While hyponatraemia is not a documented side effect of bupropion, there are a few cases outside of Australia reported in the literature. We report on a case of hyponatraemia observed on bupropion initiation in a 70-year-old female patient with treatment-resistant depression. We present a discussion of the possible mechanism of action for the hyponatraemia observed in our case and prior reported cases.

CONCLUSIONS

Our case and review of the available literature highlights the dangers of polypharmacy in the management of treatment-resistant depression. Our findings suggest that the association of hyponatraemia with bupropion in our and subsequent cases was likely the result of medication interaction and not a direct side effect of bupropion. Where bupropion is being used as an augmenting agent in the treatment of depression we would suggest checking of serum sodium prior to commencement of bupropion, and monitoring thereafter. This is especially important in elderly patients where other risk factors for hyponatraemia are likely to be present.

Antidepressants and the risk of hyponatremia: a class-by-class review of literature

BACKGROUND

Antidepressant-induced hyponatremia can cause significant morbidity and mortality. It is mostly associated with the use of selective serotonin reuptake inhibitors (SSRIs), but its frequency and class specificity are uncertain.

OBJECTIVES

To determine the relationship between hyponatremia and antidepressants and to define the incidence and odds ratios for antidepressant classes.

METHODS

A review of the literature prior to March 2013 was performed using Web of Science and PubMed by employing combinations of search strings "antidepressants" and antidepressant class and generic drug names with "hyponatr(a)emia," "SIADH," or "inappropriate ADH."

RESULTS

Overall, 21 effect studies and more than 100 case reports were considered, most concerning SSRIs. Because of variations in study designs, populations, and cutoff values, incidence rates diverged between 0.06% and 40% for SSRIs and 0.08% and 70% for venlafaxine. Although based on less solid evidence, incidence figures for mirtazapine and tricyclic antidepressants were lower. Regarding classes, odds ratios for SSRIs (1.5-21.6) were consistently higher than for tricyclic antidepressants (TCAs) (1.1-4.9). The risks associated with monoamine oxidase inhibitors, reboxetine, and bupropion could not be established owing to insufficient information. Patient risk factors included older age (odds ratios = 6.3) and concomitant use of (thiazide) diuretics (odds ratios = 11.2-13.5).

CONCLUSION

Hyponatremia is a potentially dangerous side effect of antidepressants and is not exclusive to SSRIs. Current evidence suggests a relatively higher risk of hyponatremia with SSRIs and venlafaxine, especially when combined with patient risk factors, warranting clinicians to be aware of this complication. The risks associated with mirtazapine are moderate, supporting this antidepressant as an alternative treatment for patients with (an increased risk of) hyponatremia.

Bupropion-induced hyponatremia

Although hyponatremia has been reported with the use of various antidepressants, the association of hyponatremia with bupropion has been limited to two case reports. In this case report, we present the case of a 75-year-old man who developed hyponatremia with the use of bupropion, which improved with stoppage of bupropion.