Rapid-onset hyponatremia and delirium following duloxetine treatment for postherpetic neuralgia: Case report and literature review

Therapeutic Strategies for Postherpetic Neuralgia: Mechanisms, Treatments, and Perspectives

PURPOSE OF REVIEW

Postherpetic neuralgia is an annoying pain that mainly affects older people. In order to give patients more options, this review summarizes the pharmacological and interventional treatments for postherpetic neuralgia and updates the research on the efficacy, thereby providing doctors with more treatment options. The adverse effects and effective doses of its various treatments are also presented so that the therapy can be prescribed according to their concrete physical conditions. In a word, this review is dedicated to providing a comprehensive overview of the treatment options for postherpetic neuralgia and offering patients more choices.

RECENT FINDINGS

Combinational therapy is more excellent than monotherapy. The local anesthesia and gabapentin comprised outstanding compatibility. In addition, two therapeutic tools for PHN patients, especially for the intractable ones, electroacupuncture (EA), and osteopathic manipulative treatment (OMT), show their efficacy and become potential options to alleviate pain. In terms of treatment, guidelines recommend patients use tricyclic antidepressants (TCAs), gabapentin, pregabalin, and 5% lidocaine patches as the first-line medications, and gabapentin is investigated most, especially the gabapentin enacarbil (GEn). And drug efficacy can be limited by adverse effects and tolerated doses. Interventional treatments, with their invasiveness and operational difficulty, are usually considered for intractable patients. Combinational therapies may be used when a single therapy cannot achieve the desired effect. Therapies such as OMT and EA have also been proposed to palliate pain in some cases, and future directions of treatment may be investigated in Chinese medicine and acupuncture.

Treatment for chemotherapy-induced peripheral neuropathy: A systematic review of randomized control trials

Purpose: Treatment of chemotherapy-induced peripheral neuropathy (CIPN) is challenging for clinicians, and many clinical trials and meta-analyses on CIPN are controversial. There are also few comparisons of the efficacy among drugs used to treat CIPN. Therefore, this systematic review aimed to study the efficacy of drugs in treating CIPN using existing randomized controlled trials. Methods: Electronic databases were searched for randomized controlled trials (RCTs) involving any pharmaceutical intervention and/or combination therapy of treating CIPN. Results: Seventeen RCTs investigating 16 drug categories, duloxetine, pregabalin, crocin, tetrodotoxin, venlafaxine, monosialotetrahexosyl ganglioside (GM1), lamotrigine, KA (ketamine and amitriptyline) cream, nortriptyline, amitriptyline, topical Citrullus colocynthis (bitter apple) oil, BAK (baclofen, amitriptyline hydrochloride, and ketamine) pluronic lecithin organogel, gabapentin, and acetyl l-carnitine (ALC), in the treatment of CIPN were retrieved. Many of the included RCTs consisted of small sample sizes and short follow-up periods. It was difficult to quantify due to the highly variable nature of outcome indicators. Conclusion: Duloxetine, venlafaxine, pregabalin, crocin, tetrodotoxin, and monosialotetrahexosyl ganglioside exhibited some beneficial effects in treating CIPN. Duloxetine, GM1, and crocin showed moderate benefits based on the evidence review, while lamotrigine, KA cream, nortriptyline, amitriptyline, and topical Citrullus colocynthis (bitter apple) oil were not beneficial. Further studies were necessary to confirm the efficacy of gabapentin in the treatment of CIPN because of the controversy of efficacy of gabapentin. Furthermore, BAK topicalcompound analgesic gel only had a tendency to improve the CIPN symptoms, but the difference was not statistically significant. ALC might result in worsening CIPN. Most studies were not of good quality because of small sample sizes. Therefore, standardized randomized controlled trials with large samples were needed to critically assess the effectiveness of these drugs in treating CIPN in the future.

Duloxetine-induced Syndrome of Inappropriate Secretion of Antidiuretic Hormone in a Super-elderly Patient

Duloxetine is widely used for pain control and depressive syndromes. One of its potential side effects is syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Duloxetine-induced SIADH causes hyponatremia, which leads to a variety of symptoms and has previously been reported in the elderly. In the present case, we experienced a case of the rapid onset of SIADH in a super-elderly woman receiving low-dose duloxetine. Elderly patients tend to have lower duloxetine doses and an earlier onset than non-elderly patients. When hyponatremia occurs after duloxetine administration, duloxetine-induced SIADH should be considered, especially in high-risk elderly patients, regardless of the duloxetine dose or duration of treatment.

Delirium and its Pharmacological Causes in Older People, Part Two

Delirium is a syndrome that can arise from many causes or underlying conditions, and though it has been reported in younger patients, it is more prevalent in older people, though it can occur in other age groups as well. Identifying delirium is challenging in older people because of the coexistence of underlying dementia or depression, which may further complicate the presentation. Drug-induced delirium is one of the major causes of delirium, and evaluation of this potential cause or contribution is an important component of the evaluation process, since it can lead to poor patient outcomes. Part one of this three part series reviewed the epidemiology, pathophysiology, evaluation, diagnostic process, and causes of delirium in older people, with a focus on the pharmacological causes. Part two of this series continues to review drugs and drug classes that can cause or contribute to delirium in older people.

An update on antidepressant pharmacotherapy in late-life depression

Introduction: Clinically important depressive symptoms that occur in adults over age 60 are often termed late-life depression (LLD). LLD poses challenges for treating clinicians in both detection and treatment. Antidepressants are the most common first-line treatment approach. Older adults are at an increased risk of adverse effects because of polypharmacy.Areas covered: This article summarizes the challenges and approaches when using pharmacotherapy in LLD with a focus on newer data that have become available during the last five years. While no new antidepressants have become available during this period, a review of the literature summarizes advances in the knowledge of the adverse effects associated with various antidepressants and on the potential contribution of pharmacogenetic tools when prescribing antidepressants to older patients.Expert opinion: During the past 5 years, most of the literature relevant to the pharmacotherapy of MDD in older patients has focused on adverse effects. In particular, the effects of antidepressants on cognition and bone are emerging as important areas for clinical attention and further investigation. There is also an emerging literature on the potential role of pharmacogenetic testing in patients with MDD, though recommendations for use in older adults await larger studies that demonstrate its efficacy and cost-effectiveness.

The risk factors of postoperative delirium in general anesthesia patients with hip fracture: Attention needed

Delirium is a common postoperative complication of patients with hip fracture, yet the risk factors for postoperative delirium in patients with hip fracture remain unclear. We aimed to evaluate the associated risk factors of postoperative delirium in patients with hip fracture, to provide evidence for formulating coping measures of postoperative delirium prevention and treatment in clinical practice.Patients undergoing surgery for hip fracture from March 1, 2018 to September 30, 2020 in our hospital were included. The related characteristics and related lab examination results were reviewed and collected. The univariate and logistic regression analyses were performed to identify the potential risk factors.A total of 462 patients were included, the incidence of postoperative delirium in patients with hip fracture was 16.02%. Logistic regression analyses indicated that history of delirium (OR = 4.38, 1.15-9.53), diabetes mellitus (OR = 5.31, 1.23-10.75), hypoalbuminemia (OR = 4.97, 1.37-9.86), postoperative hypoxemia (OR = 5.67, 2.24-13.42), and body mass index (BMI) (kg/m2) (OR = 3.03, 1.36-6.18) were the independent risk factors for the delirium in patients with hip fracture surgery (all P < 0.05). The cutoff value of postoperative blood sugar, albumin, and BMI for delirium prediction was 8.05 (mmol/L), 32.26 (g/L), and 19.35 (kg/m2), respectively, and the area under curve of postoperative blood sugar, albumin, and BMI was 0.792, 0.714, and 0.703, respectively.Those patients with a history of delirium, postoperative hypoxemia, blood glucose ≥8.05 mmol/L, albumin ≤32.26 g/L, and BMI ≤19.35 kg/m2 particularly need the attention of healthcare providers for the prevention of delirium.

Effect of duloxetine premedication for postherpetic neuralgia within 72 h of herpes zoster reactivation [PROCESS]: a study protocol for a randomized controlled trial

Background

Postherpetic neuralgia (PHN) is the most common complication attributed to herpes zoster, which involves the reactivation of residual varicella zoster virus. It has been reported previously that pre-emptive amitriptyline following acute herpes zoster has shown latent positive effects in the prevention of PHN. In this study, by interfering with the same targets, norepinephrine and serotonin, we aim to evaluate whether pre-emptive duloxetine may proactively prevent PHN development.

Methods

This is a nationwide multicentric, randomized, open-label, blinded-endpoint study that will recruit 750 participants from 18 primary centres in China. Patients aged more than 50 years who are diagnosed with uncomplicated HZ, present with vesicles within 72 h of their emergence, and have an average pain score of at least 40/100 mm on a visual analogue scale (VAS, 0 mm = no pain, 100 mm = worst possible pain, at opposite ends of a 100-mm line) will be recruited for this study. Participants will be randomized into a duloxetine arm and a control arm. Participants allocated to the duloxetine arm will be given antivirals, analgesics and duloxetine, while those allocated to the control arm will receive antivirals and analgesics but no duloxetine. The primary outcome of this study is preventive efficacy against PHN, which will be evaluated based on a 100 mm VAS. Any pain scores other than 0 mm on the VAS 12 weeks after HZ onset will be defined as PHN. The secondary outcomes will consist of the average weekly VAS score, the average weekly consumption of each analgesic, weekly feature of the pain, patients’ quality of life based on the 12-item Short-Form Health Survey, Patient Global Impression of Change Scale, sleep quality as evaluated by the Pittsburgh Sleep Quality Index and adverse events during the study period.

Discussion

This study will investigate a prophylactic approach for reducing the prevalence of postherpetic neuralgia with duloxetine and will add significant new knowledge on the preventive effects of duloxetine on PHN.

Trial registration

Clinicaltrials.gov NCT04313335. Registered on 18 March 2020.

Acute Severe Hyponatremia Induced by a Duloxetine Overdose in an Elderly Woman

We report a case of acute severe hyponatremia within 24 hours after a duloxetine overdose. An 82-year-old woman presented to the ED after ingesting duloxetine and diltiazem. She became hemodynamically unstable due to the diltiazem overdose and was appropriately resuscitated. During hospitalization she experienced hyponatremia consistent with syndrome of inappropriate antidiuretic hormone (SIADH). Based on the observations we concluded there was a probable relationship between the hyponatremia and the duloxetine overdose. Clinicians should monitor patients’ electrolytes for acute disturbances after an overdose of duloxetine.

Effects of low extracellular sodium on proliferation and invasive activity of cancer cells in vitro

PURPOSE

Hyponatremia is the most common electrolyte disorder in hospitalized patients, and its etiopathogenesis is related to an underlying tumor in 14% of cases. Hyponatremia has been associated with a worse outcome in several pathologies, including cancer, in which the leading cause of this electrolyte alteration is the syndrome of inappropriate antidiuresis. The aim of this study was to analyze in vitro the effects of low extracellular [Na⁺] in cancer progression.

MATERIALS AND METHODS

We used a previously validated experimental model of chronic hyponatremia to characterize the effects of low extracellular [Na⁺] in different human cancer cell lines: pancreatic adenocarcinoma (PANC-1), neuroblastoma (SK-N-AS, SH-SY5Y), colorectal adenocarcinoma (HCT-8), chronic myeloid leukemia (K562).

RESULTS

Our results demonstrate a direct relationship between low [Na⁺], reduced cell adhesion and increased invasion and proliferation in all cell lines tested. Accordingly, the number of tumor colonies grown in soft agar and the expression of collagenases type IV (metalloproteinases 2 and 9) were markedly higher in cancer cells exposed to reduced extracellular [Na⁺]. Gene analysis showed an upregulation of molecular pathways involved in oxidative stress (heme oxygenase 1) and in proliferation and invasion (RhoA, ROCK-1, ROCK-2). The activation of RhoA/ROCK pathway was paralleled by a deregulation of the cytoskeleton-associated proteins, resulting in the promotion of actin cytoskeletal remodeling and cell invasion.

CONCLUSIONS

Overall, our data demonstrate for the first time that low [Na⁺] promotes cancer progression in vitro, thus suggesting that hyponatremia is not a simple bystander of disease severity in cancer.

Recurrent Severe Hyponatremia in a Patient with Sjögren's Syndrome

Sjögren's syndrome (SS) is an autoimmune disease that presents with exocrine gland dysfunction. Renal involvement is common in SS and often results in tubulointerstitial nephritis, renal tubular acidosis, and Fanconi's syndrome. Electrolyte imbalances are commonly the first symptom of renal involvement of SS. The most common feature of dysnatremia in SS is hypernatremia with diabetes insipidus. However, cases of hyponatremia with syndrome of inappropriate antidiuretic hormone secretion (SIADH) are rarely reported in patients with SS. Herein, we report a case of recurrent severe SIADH in a patient with SS.

Chronic idiopathic hyponatremia in an elderly patient due to inappropriate antidiuretic hormone secretion (SIADH) syndrome

INTRODUCTION

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is a disorder which is characterized by the inability to suppress the secretion of antidiuretic hormone (ADH), leading to impaired water excretion and hyponatremia. The syndrome should be suspected in any patient with hyponatremia, hypo-osmolality and a urine osmolality >100 mOsm/kg, while urine sodium concentration is above 40 mEq/L.

CASE DESCRIPTION

Herein, we present an 84-year-old female patient with chronic idiopathic hyponatremia due to SIADH. Her laboratory tests showed hyponatremia with serum sodium of 120 mEq/L, while urine sodium concentration was 83 mEq/L. Measured serum osmolality was 255 mOsm/kg and urinary osmolality 130 mOsm/kg. In addition to these, her serum glucose, potassium, uric acid, renal, and liver functions were normal, and there were no acid-base disorders. The patient's adrenal function (cortisol, adrenocorticotropic hormone, renin, and aldosterone) showed no abnormalities, as well as her thyroid function.

DISCUSSION

The patient suffered from chronic idiopathic hyponatremia and osteoporosis, which often coexists in patients with chronic idiopathic SIADH and was treated with alendronate/cholecalciferol. The scenario of the presence of SIADH was further strengthened by the fact that hyponatremia did not improve after isotonic normal saline administration, but only with fluid restriction.  HIPPOKRATIA 2019, 23(1): 42-44.