Cardiovascular risk associated with high sodium-containing drugs: A systematic review

Increased Risk of New-Onset Hypertension in Patients With Narcolepsy Initiating Sodium Oxybate: A Real-World Study

OBJECTIVE

To compare intermediate-term risk of new-onset hypertension between normotensive patients with narcolepsy initiating sodium oxybate (SXB cohort) and those not initiating sodium oxybate (control cohort).

PATIENTS AND METHODS

This retrospective cohort study used MarketScan administrative claims data from January 1, 2014, to February 29, 2020. Eligible patients were 18 years of age or older with continuous enrollment (≥180 days before and after cohort entry), had one or more narcolepsy claims or a prescription fill for sodium oxybate, had no history of hypertension or antihypertensive medication use, and had no use of sodium oxybate within 13 months before cohort entry. Patients in the SXB and control cohorts were matched 1:2 for the propensity score to balance baseline characteristics. End points were (1) a composite of new-onset hypertension diagnosis or antihypertensive medication initiation and (2) new-onset hypertension diagnosis. Patients were monitored for 180 days, until outcome occurrence, sodium oxybate discontinuation (SXB cohort), or sodium oxybate initiation (control cohort). Risk per 100 patients was reported; differences were evaluated using logistic regression to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The SXB and control cohorts included 954 and 1908 patients, respectively. Risk of new-onset hypertension diagnosis or antihypertensive medication initiation was higher in the SXB cohort than in the control cohort (6.60 vs 4.20 per 100 patients; OR, 1.61; 95% CI, 1.15 to 2.27). Risk of a new-onset hypertension diagnosis only in the SXB cohort was 0.94 per 100 patients and 0.52 per 100 patients in the control cohort (OR, 1.81; 95% CI, 0.73 to 4.46).

CONCLUSION

In this study, sodium oxybate use was associated with a new-onset hypertension diagnosis or antihypertensive medication initiation in normotensive patients with narcolepsy.

Investigation Into Potentially Inappropriate Prescribing Patterns of Loop Diuretics in a Nationally Representative Outpatient Population

BACKGROUND

Loop diuretic therapy effectively treats edema related to heart failure, chronic kidney disease, and liver impairment; however, evidence supporting other indications is lacking. For indications such as hypertension or dependent edema or treatment of adverse events associated with other medications, the benefits likely do not outweigh the risks, putting patients at an unacceptably high risk of poor outcomes.

STUDY QUESTION

What is the proportion of loop diuretic prescribing that occurs in the absence of a diagnosis of heart failure, chronic kidney disease, liver impairment, or other evidence-based indications?

STUDY DESIGN

This was a national, retrospective, cross-sectional investigation conducted using the National Ambulatory Care Survey from 2013 to 2016. Outpatient visits for patients aged 18 years or older prescribed with loop diuretics were included.

MEASURES AND OUTCOMES

The primary end point was the frequency of potentially inappropriate loop diuretic prescribing. The secondary end point was a multivariable regression model that identified predictors of potentially inappropriate loop diuretic utilization.

RESULTS

This analysis identified 5261 outpatient visits conducted during the study period in which loop diuretics were prescribed. Of these, 3648 visits (65.8% of weighted visits) were of patients without a history of heart failure, chronic kidney disease, or liver impairment. Positive predictors included age older than 65 years (odds ratio [OR] 1.71; 95% confidence interval [CI] 1.38-2.13), concomitant calcium channel blocker (OR 1.42; 95% CI, 1.09-1.84), sodium-containing medication use (OR 2.78; 95% CI, 1.23-6.25), and office visit with a cardiology specialist (OR 2.84; 95% CI, 2.31-3.50).

CONCLUSIONS

This analysis identified that loop diuretics are prescribed in the absence of evidence-based indications more frequently than they are prescribed for them. This prescribing pattern creates a unique opportunity for clinicians to optimize patient care. Further study of the outcomes associated with this prescribing pattern is warranted.

Changes in Cataplexy Frequency in a Clinical Trial of Lower-Sodium Oxybate with Taper and Discontinuation of Other Anticataplectic Medications

BACKGROUND

Lower-sodium oxybate (LXB) is an oxybate medication with the same active moiety as sodium oxybate (SXB) and a unique composition of cations, resulting in 92% less sodium. LXB was shown to improve cataplexy and excessive daytime sleepiness in people with narcolepsy in a placebo-controlled, double-blind, randomized withdrawal study (NCT03030599). Additional analyses of data from this study were conducted to explore the effects of LXB on cataplexy, including the clinical course and feasibility of transition from other anticataplectics to LXB monotherapy.

OBJECTIVE

The aim of these analyses was to evaluate cataplexy frequency during initiation/optimization of LXB and taper/discontinuation of prior antidepressant/anticataplectic medications.

METHODS

Eligible participants (adults aged 18-70 years with narcolepsy with cataplexy) entered the study taking SXB only (group A), SXB + other anticataplectics (group B), or anticataplectic medication other than SXB (group C), or were cataplexy-treatment naive (group D). LXB was initiated/optimized during a 12-week, open-label, optimized treatment and titration period (OLOTTP). Other anticataplectics were tapered/discontinued during weeks 3-10 of OLOTTP. A 2-week stable-dose period (SDP; during which participants took a stable dose of open-label LXB) and 2-week double-blind randomized withdrawal period (during which participants were randomized to continue LXB treatment or switch to placebo) followed OLOTTP. Treatment-emergent adverse events (TEAEs) were recorded throughout the duration of the study.

RESULTS

At the beginning of OLOTTP, median weekly cataplexy attacks were lower in participants taking SXB at study entry (SXB only [2.00]; SXB + other anticataplectics [0.58]) versus participants who were taking other anticataplectics (3.50) or were anticataplectic naive (5.83). Median weekly cataplexy attacks decreased during weeks 1-2 of OLOTTP in all groups. Increased cataplexy frequency was observed in participants tapering/discontinuing other anticataplectics during weeks 3-10 and was more prominent in participants taking other anticataplectics alone compared with those taking SXB plus other anticataplectics. Cataplexy frequency decreased throughout initiation/optimization in anticataplectic-naive participants. Median number of cataplexy-free days/week at the end of SDP (study week 14) was similar in all groups (6.0, 6.1, 6.0, and 6.2 in groups A, B, C, and D, respectively). During OLOTTP and SDP, TEAEs of worsening cataplexy were reported in 0%, 47.8%, 16.7%, and 2.2% of participants in groups A, B, C, and D, respectively; most TEAEs of worsening cataplexy were reported during tapering/discontinuation of other anticataplectics.

CONCLUSIONS

LXB monotherapy was effective in reducing cataplexy and increasing cataplexy-free days. These results illustrate the feasibility of switching from SXB to LXB while tapering/discontinuing other anticataplectics.

TRIAL REGISTRATION

A Study of the Efficacy and Safety of JZP-258 in Subjects With Narcolepsy With Cataplexy; https://clinicaltrials.gov/ct2/show/NCT03030599 ; clinicaltrials.gov identifier: NCT03030599.

Calcium, Magnesium, Potassium and Sodium Oxybates (Xywav®) in Sleep Disorders: A Profile of Its Use

Calcium, magnesium, potassium and sodium oxybates (Xywav®; hereafter referred to as lower-sodium oxybate), a new oxybate formulation with a greatly reduced sodium burden compared with previously approved sodium oxybate (Xyrem®), is approved for the treatment of cataplexy and excessive daytime sleepiness (EDS) in adults and children aged ≥ 7 years with narcolepsy, and is the first drug approved for the treatment of idiopathic hypersomnia in adults in the USA. In two pivotal, double-blind, placebo-controlled, phase 3 trials of randomized-withdrawal design, lower-sodium oxybate effectively improved cataplexy and EDS in adults with narcolepsy, and EDS and overall idiopathic hypersomnia symptoms in adults with idiopathic hypersomnia during open-label titration and optimization periods. At the end of the double-blind, randomized withdrawal period, participants randomized to switch to placebo experienced significant worsening in these symptoms compared with those randomized to continue lower-sodium oxybate. Furthermore, worsening in patient- and clinical-rated global scales, as well as measures of health-related quality of life were also seen with placebo versus lower-sodium oxybate. Lower-sodium oxybate is generally well tolerated, with the tolerability profile being largely consistent to that seen with sodium oxybate.

Association Between Exposure to Effervescent Paracetamol and Hospitalization for Acute Heart Failure: A Case-Crossover Study

We investigated whether effervescent paracetamol, as an important source of non-dietary sodium and fluid load, is associated with a transient increase in the risk of hospitalization for acute heart failure (AHF). We conducted a unidirectional case-crossover study using data from the 1/97^th representative sample from the French healthcare database. Subjects aged 18 years or more, hospitalized for AHF during the 2014-2016 period were included. Exposure to effervescent paracetamol was compared between a risk period (i.e. 15 days immediately prior to admission for AHF) and three earlier 15-day control periods, to test a possible trigger effect of effervescent paracetamol intake on AHF. Adjusted odds ratios (aOR) were estimated with a conditional logistic regression. We identified 4,301 patients hospitalized for AHF. We found that 5.7% of AHF subjects were exposed to effervescent paracetamol during the risk period, as compared with 4.1% during the control periods (aOR 1.56 [CI_95% : 1.27 - 1.90], p < 0.001). This association was also found in the subgroup of subjects with hypertension (aOR 1.45 [CI_95% : 1.13 - 1.87], p = 0.004, n = 2,648) and in the subgroup of subjects aged 83 years or more (aOR 1.70 [CI_95% : 1.28 - 2.24], p < 0.001, n = 2,238). A similar analysis, considering exposure to non-effervescent paracetamol, did not support the existence of an indication bias likely to explain the association observed for effervescent paracetamol. This study suggests an association between effervescent paracetamol and admission for AHF and should be confirmed with other complementary study designs. This article is protected by copyright. All rights reserved.

Development of a lower-sodium oxybate formulation for the treatment of patients with narcolepsy and idiopathic hypersomnia

INTRODUCTION

Sodium oxybate (SXB) is a standard of care for cataplexy, excessive daytime sleepiness, and disrupted nighttime sleep in narcolepsy. At recommended dosages in adults (6-9 g/night), SXB increases daily dietary intake of sodium by 1100-1640 mg. Because excess sodium intake is associated with increased blood pressure and cardiovascular risk, an oxybate formulation containing 92% less sodium than SXB (lower-sodium oxybate; LXB) was developed to provide an alternative oxybate treatment option. In 2020, LXB was approved for treatment of cataplexy or excessive daytime sleepiness in patients 7 years of age and older with narcolepsy, and in 2021, for treatment of idiopathic hypersomnia in adults.

AREAS COVERED

Development of LXB from initial concept to regulatory approval is described, including formulation development and preclinical and clinical studies. Pharmacokinetic parameters and bioequivalence evaluations from phase 1 clinical trials are detailed. Efficacy and safety results from phase 3 clinical trials of LXB in patients with narcolepsy or idiopathic hypersomnia are presented and discussed.

EXPERT OPINION

Reducing sodium from high sodium‒containing medications is an important step to offset cardiovascular risks associated with high sodium consumption. The development of LXB exemplifies the importance of a collaborative approach to drug development, with patient needs paramount.

PLAIN LANGUAGE SUMMARY

Sodium oxybate (Xyrem®) is a medication for people with narcolepsy aged 7 years and older. Xyrem treats symptoms of excessive daytime sleepiness (EDS) or cataplexy (attacks of muscle weakness caused by emotion) in narcolepsy. At the recommended dosages in adults, Xyrem adds a large amount of sodium to daily dietary intake. Too much sodium in the diet is associated with increased blood pressure and risks of damage to the heart and blood vessels. Researchers used calcium, magnesium, and potassium ions in addition to a small amount of sodium to make a new oxybate medication, called Xywav®, that has 92% less sodium than Xyrem. Xywav and Xyrem were similar in laboratory and animal studies. In people, the body absorbs and processes Xywav slightly differently than Xyrem, but Xywav treatment has been shown to work the same to reduce symptoms of cataplexy and EDS in people with narcolepsy and is approved by the US Food and Drug Administration. Another neurological disorder with EDS is called idiopathic hypersomnia. Based on a clinical study, Xywav also reduced EDS and other symptoms in people with idiopathic hypersomnia. Side effects with Xywav are similar to those seen in previous studies with Xyrem.

From the pharmaceutical to the clinical: the case for effervescent paracetamol in pain management. A narrative review

OBJECTIVE

Paracetamol has an established place in the management of mild-to-moderate pain, but has certain limitations, including varying bioavailability, and potential hepatotoxicity if taken in overdose. Effervescent formulations may help to overcome these limitations.

METHODS

Pubmed searches, with no limits on date or language, were conducted in February 2020. Further references were identified from the reference lists of retrieved articles, and from the authors' knowledge of the field.

RESULTS

Effervescent formulations contain an organic acid (usually citric acid) and carbonate or bicarbonate salts (usually sodium bicarbonate). Upon contact with water, these react to form carbon dioxide, which facilitates the disintegration of the tablet and dissolution of the active drug. Moreover, sodium bicarbonate dose-dependently increases gastric emptying, which together with rapid dissolution facilitates drug absorption. In pharmacokinetic studies, effervescent formulations result in faster absorption of paracetamol than conventional oral formulations, and this translates into a faster onset of analgesia in clinical trials. Effervescent paracetamol has a favorable safety profile, with good tolerability. Importantly, the sodium content of some preparations does not appear to increase cardiovascular risk under real world conditions. Effervescent formulations may also offer advantages in terms of ease of administration and palatability.

CONCLUSIONS

Effervescent formulations of paracetamol result in faster drug absorption, and hence more rapid analgesia, than oral tablets, and offer a favorable tolerability and safety profile. The use of such formulations may therefore help to promote appropriate use of paracetamol.

Efficacy and safety of calcium, magnesium, potassium, and sodium oxybates (lower-sodium oxybate [LXB]; JZP-258) in a placebo-controlled, double-blind, randomized withdrawal study in adults with narcolepsy with cataplexy

Study Objectives

Evaluate efficacy and safety of lower-sodium oxybate (LXB), a novel oxybate medication with 92% less sodium than sodium oxybate (SXB).

Methods

Adults aged 18–70 years with narcolepsy with cataplexy were eligible. The study included a ≤30-day screening period; a 12-week, open-label, optimized treatment and titration period to transition to LXB from previous medications for the treatment of cataplexy; a 2-week stable-dose period (SDP); a 2-week, double-blind, randomized withdrawal period (DBRWP); and a 2-week safety follow-up. During DBRWP, participants were randomized 1:1 to placebo or to continue LXB treatment.

Results

Efficacy was assessed in 134 participants who received randomized treatment, and safety was assessed in all enrolled participants (N = 201). Statistically significant worsening of symptoms was observed in participants randomized to placebo, with median (first quartile [Q1], third quartile [Q3]) change in weekly number of cataplexy attacks from SDP to DBRWP (primary efficacy endpoint) in the placebo group of 2.35 (0.00, 11.61) versus 0.00 (−0.49, 1.75) in the LXB group (p < 0.0001; mean [standard deviation, SD] change: 11.46 [24.751] vs 0.12 [5.772]), and median (Q1, Q3) change in Epworth Sleepiness Scale score (key secondary efficacy endpoint) of 2.0 (0.0, 5.0) in the placebo group versus 0.0 (−1.0, 1.0) in the LXB group (p < 0.0001; mean [SD] change: 3.0 [4.68] vs 0.0 [2.90]). The most common treatment-emergent adverse events with LXB were headache (20.4%), nausea (12.9%), and dizziness (10.4%).

Conclusions

Efficacy of LXB for the treatment of cataplexy and excessive daytime sleepiness was demonstrated. The safety profile of LXB was consistent with SXB.

Clinical trial registration

NCT03030599.

Changes in prescribing rates of sodium-containing medications in the UK from 2009 to 2018: a cross-sectional study with interrupted time series analysis

OBJECTIVE

Effervescent, soluble, dispersible formulations contain considerable amounts of sodium. In 2013, we previously confirmed the association between sodium-containing medications and cardiovascular risks. This study aimed to determine the changes in the prescribing pattern in clinical practice following this publication.

DESIGN

A longitudinal cross-sectional study.

SETTING

Primary care in the UK from 2009 to 2018.

PARTICIPANTS

Prescribing information in The Health Improvement Network (THIN) and Prescription Cost Analysis (PCA) databases in the UK.

OUTCOME MEASUREMENTS

Prescription rates per 10 000 inhabitants were calculated using the number of prescriptions or the number of drug-using patients over the total number of inhabitants, and the prescription rates were measured at annual intervals. Prescribing trends from 2009 to 2018 were indexed with yearly data from THIN and PCA. Interrupted time series analysis (ITSA) was conducted with monthly data in THIN.

RESULTS

From the THIN database, a total of 3 651 419 prescription records from 446 233 patients were included. The prescribing rate of sodium-containing medications changed from 848.3/10 000 inhabitants in 2009 to 571.6/10 000 inhabitants in 2018. The corresponding figures from PCA data were of 631.0/10 000 inhabitants in 2009 and 423.8/10 000 inhabitants in 2018. ITSA showed the prescribing trend reduced significantly during the postpublication period (prescribing rate: slope change=-0.26; 95% CI -0.45 to -0.07; p=0.009; proportion of patients: slope change=-0.22; 95% CI -0.35 to -0.09; p<0.001), but no change in postpublication level from baseline. The prescribing rates for the non-sodium-containing standard formulations were relatively stable over the study period. The reduction in the proportion of patients using sodium-containing medications was only significant in patients over 45 years old.

CONCLUSIONS

The prescribing of sodium-containing medications in the UK primary care has declined significantly during the postpublication period. Changes in the prescribing trends for sodium-containing medications varied across regions of the UK and patient age groups.

Cardiovascular disorders in narcolepsy: Review of associations and determinants

Narcolepsy type 1 (NT1) is a lifelong disorder of sleep-wake dysregulation defined by clinical symptoms, neurophysiological findings, and low hypocretin levels. Besides a role in sleep, hypocretins are also involved in regulation of heart rate and blood pressure. This literature review examines data on the autonomic effects of hypocretin deficiency and evidence about how narcolepsy is associated with multiple cardiovascular risk factors and comorbidities, including cardiovascular disease. An important impact in NT1 is lack of nocturnal blood pressure dipping, which has been associated with mortality in the general population. Hypertension is also prevalent in NT1. Furthermore, disrupted nighttime sleep and excessive daytime sleepiness, which are characteristic of narcolepsy, may increase cardiovascular risk. Patients with narcolepsy also often present with other comorbidities (eg, obesity, diabetes, depression, other sleep disorders) that may contribute to increased cardiovascular risk. Management of multimorbidity in patients with narcolepsy should include regular assessment of cardiovascular health (including ambulatory blood pressure monitoring), mitigation of cardiovascular risk factors (eg, cessation of smoking and other lifestyle changes, sleep hygiene, and pharmacotherapy), and prescription of a regimen of narcolepsy medications that balances symptomatic benefits with cardiovascular safety.

The sodium in sodium oxybate: is there cause for concern?

Sodium oxybate (SO), the sodium salt of γ-hydroxybutyric acid, is one of the primary pharmacologic agents used to treat excessive sleepiness, disturbed nighttime sleep, and cataplexy in narcolepsy. The sodium content of SO ranges from 550 to 1640 mg at 3-9 g, given in two equal nightly doses. Clinicians are advised to consider daily sodium intake in patients with narcolepsy who are treated with SO and have comorbid disorders associated with increased cardiovascular (CV) risk, in whom sodium intake may be a concern. It remains unclear whether all patients with narcolepsy treated with SO should modify or restrict their sodium intake. No data are currently available specific to the sodium content or threshold of SO at which patients might experience increased CV risk. To appraise attributable risk, critical evaluation of the literature was conducted to examine the relationship between CV risk and sodium intake, narcolepsy, and SO exposure. The findings suggest that increased CV risk is associated with extremes of daily sodium intake, and that narcolepsy is associated with comorbidities that may increase CV risk in some patients. However, data from studies regarding SO use in patients with narcolepsy have shown a very low frequency of CV side effects (eg, hypertension) and no overall association with CV risk. In the absence of data that specifically address CV risk with SO based on its sodium content, the clinical evidence to date suggests that SO treatment does not confer additional CV risk in patients with narcolepsy.

Evaluation of exposure to effervescent drugs in a large health check-up population in France: a cross-sectional study

OBJECTIVES

The relationship between high dietary sodium intake and hypertension is well established. Some drugs are associated with high-sodium content, particularly effervescent tablets (ETs). Despite a possible cardiovascular risk associated with the use of such drugs, observational data describing exposure to ETs in ambulatory subjects are lacking.This study aims to estimate the prevalence of exposure to ETs and to highlight factors associated with this exposure in a large French health check-up population.

DESIGN

This was a cross-sectional study.

SETTING AND PARTICIPANTS

Participants were French individuals who underwent medical check-ups at the Investigations Préventives et Cliniques centre between April and June 2017.

RESULTS

In total, 1043 subjects were included in the study. The prevalence of exposure to ETs in the last 30 days was 26.9% (95% CI 24.2% to 29.6%). Exposure was frequent (ie, two ETs per week or more in the last 30 days) for 7.3% of subjects. Self-medication was the major source of exposure (93.8%). Paracetamol, aspirin, vitamins and betaine accounted for 95.3% of the ETs used. The factors associated with this exposure by multivariate analysis were: male gender, Overseas French origin, depression and body mass index ≥25 kg/m². A diagnosis of hypertension or treatment with diuretics were not protective factors against exposure to ETs.

CONCLUSION

Exposure to ETs is frequent in the general population, particularly through self-medication. Clinical conditions associated with low-salt requirements were not associated with lower exposure to ETs, suggesting a lack of awareness by practitioners and patients about this iatrogenic issue.