Antidépresseurs et hyponatrémie : revue de littérature et analyse cas/non-cas dans la base nationale de pharmacovigilance française

The risk of antidepressant-induced hyponatremia: A meta-analysis of antidepressant classes and compounds

BACKGROUND

Hyponatremia (hypoNa) is a potentially serious adverse event of antidepressant treatment. Previous research suggests the risk of drug-induced hyponatremia differs between antidepressants. This meta-analysis sought to determine the risk of antidepressant-induced hypoNa, stratified by different compounds and classes.

METHODS

A PRISMA-compliant systematic search of Web of Science and PubMed databases was performed from inception until Jan 5, 2023, for original studies reporting incidences or risks of hypoNa in adults using antidepressants. We modelled random-effects meta-analyses to compute overall event rates and odds ratios of any and clinically relevant hypoNa for each compound and class, and ran head-to-head comparisons based on hypoNa event rates. We conducted subgroup analyses for geriatric populations and sodium cut-off value. The study is registered with PROSPERO, CRD42021269801.

RESULTS

We included 39 studies (n = 8,175,111). Exposure to antidepressants was associated with significantly increased odds of hypoNa (k = 7 studies, OR = 3.160 (95%CI 1.911-5.225)). The highest event rates were found for SNRIs (7.44%), SSRIs (5.59%), and TCAs (2.66%); the lowest for mirtazapine (1.02%) and trazodone (0.89%). Compared to SSRIs, SNRIs were significantly more likely (k = 10, OR = 1.292 (1.120 - 1.491), p < 0.001) and mirtazapine significantly less likely (k = 9, OR = 0.607 (0.385 - 0.957), p = 0.032) to be associated with hypoNa.

CONCLUSION

Our meta-analysis demonstrated that, while no antidepressant can be considered completely risk-free, for hypoNa-prone patients mirtazapine should be considered the treatment of choice and SNRIs should be prescribed more cautiously than SSRIs and TCAs.

Eosinophilic granulomatosis with polyangiitis as a rare cause of the syndrome of inappropriate antidiuretic hormone secretion

Eosinophilic granulomatosis with polyangiitis (EGPA, Churg-Strauss syndrome) is a rare multisystem necrotizing vasculitis that involves small- to medium-sized blood vessels. We report a rare case of syndrome of the inappropriate antidiuretic hormone (ADH) secretion (SIADH) secondary to EGPA. A 53-year-old man applied with complaints of pain in the large joints and morning stiffness in knee for 2 months. The patient had the history of impaired fasting glucose, asthma, nasal polyps, and urticaria. Physical examination revealed intrinsic muscle atrophy and weakness in the right hand. Peripheral eosinophil count was 9.78 × 109/L (0.02-0.5), erythrocyte sedimentation rate 39 mm/h (0-20), and C-reactive protein 5.77 mg/dL (0-0.5). Migratory ground-glass pulmonary opacities had been reported in previous chest computed tomography scans. Echocardiography revealed findings compatible with eosinophilic involvement. Electroneuromyographic evaluation showed acute distal axonal neuropathy of right ulnar nerve. EGPA was considered. Oral methylprednisolone treatment was initiated. Intravenous immunoglobulin (IVIG) and cyclophosphamide treatment and gradual tapering of oral steroids were planned. In 24-h urine analysis, sodium was 387 mEq, creatinine was 1156 mg, and volume was 3000 mL. When his medical records were investigated, it was observed that hyponatremia was present for nearly 2 years. While serum osmolality was 270, urine osmolality was 604 mOsm/kg H₂O. So, SIADH diagnosis was made. Fluid intake was restricted. Although the patient's sodium level did not return to normal, it rose up to 130 mEq/L. After second cycle of EGPA treatment (cyclophosphamide and IVIG), serum sodium was normal. There is only four other documented cases of SIADH associated with EGPA. We hypothesized that blood supply to the hypothalamus and/or posterior hypophysis might be affected from EGPA vasculitis. Here, in this case, with effective treatment of EGPA, SIADH was resolved which implies a causality between two conditions.

[Therapeutic drug monitoring of antidepressants: Why venlafaxine is the most monitored drug? A review of literature]

Venlafaxine is the third most frequently prescribed antidepressant in France the last decade, with about 400,000 daily doses. Therapeutic drug monitoring (TDM) of this medication, by measuring the active moiety venlafaxine (V) and O-desmethylvenlafaxine (ODV), is recommended (level of recommendation 2). However, this antidepressant seems to be the one for which clinicians most often use TDM, much more frequently than escitalopram, which is more prescribed and for which TDM is also recommended. The main goal of this review is to provide an update on the TDM of venlafaxine: its therapeutic interval, its level of recommendation and the origin of its "success". From the literature does not enable to define a therapeutic interval for the active moiety V+ODV, that is to say a steady-state trough concentration allowing a clinical response without toxicity. Nevertheless, a target concentration from 100 to 400μg/L is certainly relevant for the majority of patients without any pharmacodynamic resistance ; though a greater concentration could result in an earlier response or could be required for a clinical response in a minority of patients. A patient with no clinical response despite a concentration greater than 1000μg/L should be proposed another antidepressant. Measurement of the ODV/V ratio is also a useful tool, values below 0.3 usually reflecting a slow metabolizer phenotype for cytochrome P-450 2D6, which is more at risk of adverse effects. Research for this phenotype probably explains many prescriptions for TDM.

[Hyponatremia in older persons (II)-A clear treatment : How to detect tricks and avoid pitfalls]

The aim of this continuing medical education (CME) article (part II) is to describe the particular challenge of the treatment of hyponatremia, which occurs in older patients. This part II follows on from part I concerning the diagnosis in the previous volume. A staged approach is necessary. The best treatment is always when the underlying cause can be eliminated. Hyponatremia in older patients is mainly induced by the syndrome of inappropriate antidiuretic hormone (SIADH) secretion. The authors use a concept for the first, second and third line strategy: (1) changing or discontinuation of drugs, (2) fluid restriction and (3) tolvaptan medication. The algorithm for treatment should be simple. It also contains recommendations for the correction rate. Caution is also needed in order to avoid the occurrence of an osmotic demyelination syndrome (ODS).

Association of sleep among 30 antidepressants: a population-wide adverse drug reaction study, 2004-2019

Background

Sleep is one of the most essential processes required to maintain a healthy human life, and patients experiencing psychiatric illness often experience an inability to sleep. The aim of this study is to test the hypothesis that antidepressant compounds with strong binding affinities for the serotonin 5-HT2C receptor, histamine H1 receptors, or norepinephrine transporter (NET) will be associated with the highest odds of somnolence.

Methods

Post-marketing cases of patient adverse drug reactions were obtained from the United States Food and Drug Administration Adverse Events Reporting System (FAERS) during the reporting window of January 2004 to September 2019. Disproportionality analyses of antidepressants reporting somnolence were calculated using the case/non-case method. The reporting odds-ratios (ROR) and corresponding 95% confidence interval (95% CI) were computed and all computations and graphing conducted in R.

Results

There were a total of 69,196 reported cases of somnolence out of a total of 7,366,864 cases reported from January 2004 to September 2019. Among the 30 antidepressants assessed, amoxapine (n = 16) reporting odds-ratio (ROR) = 7.1 (95% confidence interval [CI] [4.3–11.7]), atomoxetine (n = 1,079) ROR = 6.6 (95% CI [6.2–7.1]), a compound generally approved for attention deficit hyperactivity disorder (ADHD), and maprotiline (n = 18) ROR = 6.3 (95% CI, 3.9–10.1) were the top three compounds ranked with the highest reporting odds of somnolence. In contrast, vortioxetine (n = 52) ROR = 1.3 (95% CI [1.0–1.8]), milnacipran (n = 58) ROR = 2.1 (95% CI [1.7–2.8]), and bupropion (n = 1,048) ROR = 2.2 (95% CI [2.1–2.4]) are least significantly associated with somnolence. Moreover, levomilnacipran (n = 1) ROR = 0.4 (95% CI [0.1–2.9]) was not associated with somnolence.

Conclusion

Among the thirty tested antidepressants, consistent with the original hypothesis, amoxepine has strongest 5-HT2C receptor binding affinity and has the highest reporting odds of somnolence. Atomoxetine, ranked second in reporting odds of somnolence overall, binds to the NET with with the strongest binding affinity among the thirty compounds. Mirtazapine, a tetracyclic antidepressant, was ranked 11th in reporting odds of somnolence and had the strongest H1 receptor binding affinity. This study provides an informative ranking of somnolence among thirty antidepressant compounds with an already wide array of clinical indications as well as provides insight into potential drug repurposing in psychopharmacology.

Cytochrome P450-mediated inhibition of venlafaxine metabolism by trimipramine

OBJECTIVE

The aim of this study was to ensure patients' safety and to enhance treatment efficacy, knowledge about pharmacokinetic interactions even in complex clinical situations of polypharmacy is invaluable. This study is to uncover the potential of pharmacokinetic interactions between venlafaxine and trimipramine in a naturalistic sample.

METHODS

Out of a therapeutic drug monitoring database with plasma concentrations of venlafaxine (VEN) and O-desmethylvenlafaxine (ODV), we considered two groups of patients receiving venlafaxine without known cytochrome P450 confounding medications, taking solely venlafaxine: V0 (n = 905), and a group of patients co-medicated with trimipramine, VTRIM (n = 33). For VEN, ODV and active moiety (sum of VEN + ODV) plasma concentrations and dose-adjusted concentrations as well as ODV/VEN ratios were compared between groups using the Mann-Whitney U test with a significance level of 0.05.

RESULTS

Patients co-medicated with trimipramine had higher plasma concentrations of VEN (183.0 vs. 72.0, +154%, P = 0.002) and AM (324.0 vs. 267.5, +21%, P = 0.005) and higher dose adjusted plasma concentrations than patients in the control group (P = 0.001 and P = 0.003). No differences were found for ODV and C/D ODV (P < 0.05 for both comparisons). The metabolite to parent ratio, ODV/VEN, was significantly lower in the VTRIM group (1.15 vs. 2.37, P = 0.012).

CONCLUSION

Findings suggest inhibitory effects of trimipramine on venlafaxine pharmacokinetics most likely via an inhibition of CYP 2D6 or by saturated enzyme capacity. The lack of in vitro data hampers the understanding of the exact mechanisms. Clinicians should be aware of drug-drug interactions when combining these agents. Therapeutic drug monitoring helps to ensure treatment efficacy and patients' safety.

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.

Interest of pharmacoepidemiology for pharmacodynamics and analysis of the mechanism of action of drugs

Pharmacology is often divided in separate branches, such as molecular and cellular pharmacology, pharmacokinetics, pharmacodynamics, experimental and/or preclinical pharmacology, clinical pharmacology (and therapeutics), pharmacogenetics, pharmacogenomics, pharmacovigilance, pharmacoepidemiology, pharmacoeconomics… This enumeration gives a global picture of different scientific areas, which are however dealing with the same question. Another mindset should be a global interactive and continuous approach, which could be designed as "human pharmacology". An original and attractive way to illustrate this continuous approach is to combine pharmacodynamics and pharmacovigilance and/or pharmacoepidemiologic data. Coupling disproportionality analyses in pharmacovigilance databases or computerized health databases, with pharmacological characteristics of drugs (receptor affinity, for example) allows investigating in humans, the mechanism of adverse drug reactions. Examples of such analyses investigating the risk of movement disorders, diabetes related to psychoactive drugs, or the risk of adverse cardiac outcomes with different drugs (classical drugs or protein kinase inhibitors) are given. The increasing number of research works investigating this topic underlines the importance of this relatively new approach, which gives significant inputs for the better knowledge of drug safety.