Risk of digoxin intoxication in heart failure patients exposed to digoxin-diuretic interactions: a population-based study

Prevalence and differences in the co-administration of drugs known to interact: an analysis of three distinct and large populations

BACKGROUND

The co-administration of drugs known to interact greatly impacts morbidity, mortality, and health economics. This study aims to examine the drug-drug interaction (DDI) phenomenon with a large-scale longitudinal analysis of age and gender differences found in drug administration data from three distinct healthcare systems.

METHODS

This study analyzes drug administrations from population-wide electronic health records in Blumenau (Brazil; 133 K individuals), Catalonia (Spain; 5.5 M individuals), and Indianapolis (USA; 264 K individuals). The stratified prevalences of DDI for multiple severity levels per patient gender and age at the time of administration are computed, and null models are used to estimate the expected impact of polypharmacy on DDI prevalence. Finally, to study actionable strategies to reduce DDI prevalence, alternative polypharmacy regimens using drugs with fewer known interactions are simulated.

RESULTS

A large prevalence of co-administration of drugs known to interact is found in all populations, affecting 12.51%, 12.12%, and 10.06% of individuals in Blumenau, Indianapolis, and Catalonia, respectively. Despite very different healthcare systems and drug availability, the increasing prevalence of DDI as patients age is very similar across all three populations and is not explained solely by higher co-administration rates in the elderly. In general, the prevalence of DDI is significantly higher in women - with the exception of men over 50 years old in Indianapolis. Finally, we show that using proton pump inhibitor alternatives to omeprazole (the drug involved in more co-administrations in Catalonia and Blumenau), the proportion of patients that are administered known DDI can be reduced by up to 21% in both Blumenau and Catalonia and 2% in Indianapolis.

CONCLUSIONS

DDI administration has a high incidence in society, regardless of geographic, population, and healthcare management differences. Although DDI prevalence increases with age, our analysis points to a complex phenomenon that is much more prevalent than expected, suggesting comorbidities as key drivers of the increase. Furthermore, the gender differences observed in most age groups across populations are concerning in regard to gender equity in healthcare. Finally, our study exemplifies how electronic health records' analysis can lead to actionable interventions that significantly reduce the administration of known DDI and its associated human and economic costs.

Bidirectional ventricular tachycardia due to digoxin-diuretic interaction in post-cardiac surgery patient: a case report

Bidirectional ventricular tachycardia (BVT) is a rare form of malignant ventricular arrhythmia characterized by beat-to-beat alternation in the QRS axis. BVT is a hallmark of digitalis toxicity, but digoxin-induced BVT secondary to digoxin-diuretic interaction in cardiac surgery patients is not widely reported. We present the case of a 62-year-old woman undergoing mitral valve replacement with tricuspid annuloplasty who developed postoperative congestive heart failure and vasoplegic syndrome requiring norepinephrine, vasopressin, and loop diuretics. During postoperative care, she presented atrial fibrillation with rapid ventricular response, achieving rate control with digoxin, but later displayed hemodynamically stable BVT associated with digitalis toxicity. The case highlights the importance of physicians monitoring digoxin toxicity when prescribing digoxin to patients with a diuretic regimen, particularly loop diuretics. During digoxin-induced-BVT, supportive treatment, including discontinuing digitalis coupled with potassium and magnesium supplements, can be considered as long as digoxin-specific antibodies are unavailable, and the patient is hemodynamically stable.

Retrospective Analysis of Potential Adverse Drug Interactions in the Drugs Prescribed to the Elderly at a Tertiary Health Care Center in Raipur, Chhattisgarh, Central India

Background The elderly population differs from adults in having various physiological changes and multiple diseases, which demand the use of multiple medications. The practice of polypharmacy in the elderly leads to numerous harmful effects like adverse drug reactions, adverse drug-drug interactions (DDIs), poor compliance, etc. Methodology This study collected 295 case files of elderly patients retrospectively in the Departments of General Medicine, Cardiology and Nephrology after obtaining Institute Ethics Committee approval to look for the potential adverse DDIs with their severity according to the clinical significance. Results and interpretation The total number of adverse DDIs identified was 156, the maximum in Category 'C.' Salbutamol plus carvedilol/propranolol, ramipril plus telmisartan and ivabradine plus diltiazem were the adverse DDIs categorized under severity 'X'. The identified DDIs were categorised according to the mechanism such as increased bleeding risk, hypokalemia, hyperkalaemia, reduced effect of drugs and increased effect of drugs.  Conclusion Polypharmacy can lead to several adverse consequences in the elderly, of which adverse DDIs play a crucial role in harmful health outcomes. This study brings out the significance of predicting drug interactions beforehand which can reduce the risk of bleeding and other risks of hyper/hypokalaemia, hyponatremia and hypoglycaemia.

Potential Effects of Digoxin on Renal Functions in Patients With Congestive Heart Failure

INTRODUCTION

Renal dysfunction is a common complication among patients with congestive heart failure (CHF) and can significantly impact their management, especially when medications like digoxin are involved. The clearance of digoxin is closely tied to the glomerular filtration rate (GFR), which suggests that the safety and efficacy of digoxin may vary with renal function. Therefore, this study aimed to assess the potential effects of digoxin on renal function in patients diagnosed with CHF at a tertiary hospital in the Asir region of Saudi Arabia.

METHODS

A retrospective study examined the records of 30 CHF patients treated with digoxin. Renal function markers like estimated GFR (eGFR), creatinine, blood urea nitrogen (BUN), albumin, and urine levels were compared before and after digoxin treatment. Liver enzymes and other relevant parameters were also examined. A statistical analysis using t-tests was conducted to evaluate the changes in renal function indicators before and after digoxin treatment.

RESULTS

The mean eGFR decreased significantly from 65.4 ± 8.9 mL/min/1.73m2 before digoxin to 57.7 ± 7.8 mL/min/1.73m2 after (p = 0.001). Creatinine, BUN, albumin, and urine levels showed no significant changes. Digoxin significantly increased aspartate aminotransferase (AST) from 34.5 ± 11.6 U/L to 53.8 ± 14.6 U/L (p = 0.002), alanine aminotransferase (ALT) from 38.5 ± 12.6 U/L to 55.3 ± 17.6 U/L (p = 0.013), and creatine kinase from 117.7 ± 22.5 U/L to 133.9 ± 15.8 U/L (p = 0.012). Hemoglobin decreased significantly from 12.8 ± 1.4 g/dL to 12.1 ± 1.4 g/dL (p = 0.034). No significant changes occurred in myoglobin, troponin, bilirubin, platelets, potassium, calcium, or chloride levels. Effects on kidney function did not differ significantly by gender or age, except blood urea nitrogen was higher in patients over 50 years (8.3 ± 2.3 vs. 5.6 ± 2.7 mg/dL, p = 0.015).

CONCLUSION

This study suggests digoxin may adversely affect renal function in CHF patients, as evidenced by reduced eGFR. However, the small retrospective design limits definitive conclusions. Further prospective research with larger samples is warranted to elucidate digoxin's renal effects in CHF patients.

Analysis of electronic health records from three distinct and large populations reveals high prevalence and biases in the co-administration of drugs known to interact

The co-administration of drugs known to interact has a high impact on morbidity, mortality, and health economics. We study the drug-drug interaction (DDI) phenomenon by analyzing drug administrations from population-wide Electronic Health Records (EHR) in Blumenau (Brazil), Catalonia (Spain), and Indianapolis (USA). Despite very different health care systems and drug availability, we find a common large risk of DDI administration that affected 13 to 20% of patients in these populations. In addition, the increasing risk of DDI as patients age is very similar across all three populations but is not explained solely by higher co-administration rates in the elderly. We also find that women are at higher risk of DDI overall- except for men over 50 years old in Indianapolis. Finally, we show that PPI alternatives to Omeprazole can reduce the number of patients affected by known DDIs by up to 21% in both Blumenau and Catalonia, and 2% in Indianapolis, exemplifying how analysis of EHR data can lead to a significant reduction of DDI and its associated human and economic costs. Although the risk of DDIs increases with age, administration patterns point to a complex phenomenon that cannot be solely explained by polypharmacy and multimorbidity. The lack of safer drug alternatives, particularly for chronic conditions, further overburdens health systems, thus highlighting the need for disruptive drug research.

Identification of Potential of Drug-Drug Interaction and Its Affecting Factors: A cross-sectional study among hospitalized coronary heart disease patients

Background:

Coronary Heart Disease (CHD) patients are at risk of suffering from drug interactions, leading to a higher risk of mortality and morbidity among these patients. This study aims to identify the potential drug-drug interactions (PDDIs) and CHD patients' related factors.

Methods:

A cross-sectional study was performed among the CHD patients to identify the PDDIs from 2014 to 2017 at Secondary Hospital. The PDDIs were categorized according to the interaction mechanism, onset, severity, and documentation.

Results:

Among 91 CHD patients, 151 PDDIs were identified consisting of pharmacodynamics mechanism and delayed onset, 50.33% and 83.44%, respectively. Furthermore, there was a correlation between the number of PDDIs and the number of drugs (r = 0.496; p < 0,001).

Conclusion:

: This study revealed that the more the drugs were prescribed to CHD patients, the more the PDDIs risk would occur. The regular monitoring of the CHD patient’s prescriptions is noteworthy to avoid the PDDIs.

A Comprehensive Review of the Pharmacologic Perspective on Loop Diuretic Drug Interactions with Therapeutically Used Drugs

Background:

Loop diuretics help to manage the patients with edema associated with congestive heart failure, liver cirrhosis, and renal disease and hypertension. The patients taking loop diuretics may receive other medications to treat comorbidities leading to drug interactions.

Methodology:

The literature was searched in databases such as Medline/PMC/PubMed, Google Scholar, Cochrane Library, Science Direct, EMBASE, Web of science, Ebsco, Directory of open access journals (DOAJ) and reference lists to spot relevant articles using the keywords Drug interactions, Pharmacodynamic interactions, Loop diuretics, Bumetanide, Ethacrynic acid, Furosemide, and Torsemide.

Results:

Loop diuretics are associated with hypokalemia, ototoxicity and other adverse effects. The drugs affected by hypokalemia, and having the potential of inducing ototoxicity could interact with loop diuretics pharmacodynamically. Loop diuretics can interact with drugs such as amphotericin B, digoxin, angiotensin-converting enzyme inhibitors (ACE inhibitors), antidiabetic drugs, antifungal agents, dobutamine, gossypoland sotalol due to diuretic associated hypokalemia. In addition, the risk of ototoxicity could be enhanced by the concomitant use of loop diuretics and cisplatin, aminoglycoside antibiotics or phosphodiesterase 5 (PDE 5) inhibitors. Loop diuretics may also interact pharmacodynamically with drugs like cephalosporins, ceritinib, levothyroxine, pixantrone, probenecid, lithium, non-steroidal anti-inflammatory drugs (NSAIDs), sulfonylureas and herbal drugs.

Conclusion:

Clinicians, pharmacists and other health care providers should take responsibility for the safe use of medications. In addition, they are required to be aware of the drugs interacting with loop diuretics, to prevent adverse drug interactions.

Digoxin: Pharmacology and toxicology-A review

Digoxin is a cardiac glycoside used as drug in case of heart problems, including congestive heart failure, atrial fibrillation or flutter, and certain cardiac arrhythmias. It has a very narrow therapeutic window of the medication. Digoxin is toxic substance with well known cardiotoxic effect. In this work, pharmacology and toxicology of digoxin are summarized; Its pharmacokinetics, pharmacodynamics, available acute toxicity data (different species, different administration routes) are summarized in this article. Moreover, its treatment side effect and human poisonings are thoroughly discussed. Finally, appropriate therapy regimen is proposed.

Simultaneous determination of canrenone, digoxin and tolvaptan by UHPLC-MS/MS: application in heart failure patients

Aim: Heart failure patients are frequently given comedication of digoxin and diuretics like spironolactone and tolvaptan. A UHPLC-MS/MS assay for determining canrenone (main active metabolite of spironolactone), digoxin and tolvaptan simultaneously should be developed so as to support related drug-drug interaction studies. Results: A UHPLC-MS/MS method for simultaneous determination of these three drugs in human plasma was established and fully verified as per CFDA guidelines. Chromatographic separation was achieved using a 4-min isocratic elution. Mass analyses were performed under positive electrospray ionization mode. The calibration curves were established over 1.0-400.0 ng/ml for canrenone and tolvaptan while over 0.1-40.0 ng/ml for digoxin. Conclusion: The developed method was feasible in detecting concentration and related drug-drug interaction studies.

Digoxin Use and Associated Adverse Events Among Older Adults

BACKGROUND

Over the past 2 decades, guidelines for digoxin use have changed significantly. However, little is known about the national-level trends of digoxin use, hospitalizations for toxicity, and subsequent outcomes over this time period.

METHODS

To describe digoxin prescription trends, we conducted a population-level, cohort study using data from IQVIA, Inc.'s National Prescription Audit (2007-2014) for patients aged ≥65 years. Further, in a national cohort of Medicare fee-for-service beneficiaries aged ≥65 years in the United States, we assessed temporal trends of hospitalizations associated with digoxin toxicity and the outcomes of these hospitalizations between 1999 and 2013.

RESULTS

From 2007 through 2014, the number of digoxin prescriptions dispensed decreased by 46.4%; from 8,099,856 to 4,343,735. From 1999 through 2013, the rate of hospitalizations with a principal or secondary diagnosis of digoxin toxicity decreased from 15 to 2 per 100,000 person-years among Medicare fee-for-service beneficiaries. In-hospital and 30-day mortality rates associated with hospitalization for digoxin toxicity decreased significantly among Medicare fee-for-service beneficiaries; from 6.0% (95% confidence interval [CI], 5.2-6.8) to 3.7% (95% CI, 2.2-5.7) and from 14.0% (95% CI, 13.0-15.2) to 10.1% (95% CI, 7.6-13.0), respectively. Rates of 30-day readmission for digoxin toxicity decreased from 23.5% (95% CI, 22.1-24.9) in 1999 to 21.7% (95% CI, 18.0-25.4) in 2013 (P < .05).

CONCLUSION

While digoxin prescriptions have decreased, it is still widely prescribed. However, the rate of hospitalizations for digoxin toxicity and adverse outcomes associated with these hospitalizations have decreased. These findings reflect the changing clinical practice of digoxin use, aligned with the changes in clinical guidelines.

Association between Sedative-hypnotics and Subsequent Cancer in Patients with and without Insomnia: A 14-year Follow-up Study in Taiwan

Background: The aim of this population-based 14-year historical and prospective study was to determine the relationships between the usage of sedative-hypnotics, including benzodiazepines and nonbenzodiazepines, and the risk of subsequent cancer in patients with or without insomnia among the Taiwanese population.

Methods: A total of 43,585 patients were recruited, 21,330 of whom had been diagnosed with insomnia and 8,717 who had been prescribed sedative-hypnotics during this study's following period of 2002 to 2015. Information from the claims data, namely basic demographic details, drug prescriptions, comorbidities, and patients' survival, was extracted from the National Health Insurance Research Database for χ² analysis. A Cox proportional hazards model was used to compute the 14-year cancer-free survival rates after adjustment for confounding factors.

Results: Patients with insomnia who used sedative-hypnotics had an adjusted hazard ratio of 1.49 compared with patients with insomnia who did not use any sedative-hypnotics, and patients without insomnia who used sedative-hypnotics had an adjusted hazard ratio of 1.68 compared with patients without insomnia who did not use any sedative-hypnotics. Regarding site-specific risk, patients with insomnia who used sedative-hypnotics had an increased risk of oral and breast cancers, and patients without insomnia who received sedative-hypnotics prescriptions had an increased risk of liver and breast cancers. The cancer-free survival rate of patients who had used sedative-hypnotics was significantly lower than that of patients who had never used sedative-hypnotics.

Conclusions: The use of sedative-hypnotics in patients either with or without insomnia was associated with subsequent cancer development in the Taiwanese population. Increased risks of oral, liver, and breast cancer were found in the patients with the use of sedative-hypnotics. The use of sedative-hypnotics should be discouraged for treating patients with or without insomnia in Taiwan.

Risk of cancer in patients with heart failure who use digoxin: a 10-year follow-up study and cell-based verification

Heart failure (HF) is the leading cause of death in the world and digoxin remains one of the oldest therapies for HF. However, its safety and efficacy have been controversial since its initial use and there is uncertainty about its long-term efficacy and safety. Recently, the repositioning of cardiac glycosides is to function in anti-tumor activity via multiple working pathways. It is interesting to compare the potential effects of digoxin in clinical patients and cell lines. First, we analyze patient information retrieved from the National Health Insurance Research database of Taiwan between January 1, 2000 and December 31, 2000. This retrospective study included a study cohort (1,219 patients) and a comparison cohort. Our analytical data suggested that patients taking digoxin are at an increased risk of cancers, including breast, liver, and lung cancers, during the 10-year follow-up period. In contrast to the anti-tumor function of digoxin, we further examined the potential pathway of digoxin via the cell-based strategy using several breast cancer cell lines, including MCF-7, BT-474, MAD-MB-231, and ZR-75-1. Digoxin consistently exerted its cytotoxicity to these four cell lines with various range of concentration. However, the proliferation of ZR-75-1 cells was the only cell lines induced by digoxin and the others were dramatically suppressed by digoxin. The responsiveness of SRSF3 to digoxin might be involved with cell-type differences. In summary, we combined a cohort study for digoxin treatment for HF patients with a cell-based strategy that addresses the translation issue, which revealed the complexity of personalized medicine.

Compatibility of medication with PRISCUS criteria and identification of drug interactions in a large cohort of patients with COPD

Patients with COPD are often of advanced age and have a high number of medications due to their lung disease and comorbidities. Thus they are at risk for unwanted effects from drugs, either due to age or due to interactions between drugs. These issues are not clarified. We therefore assessed the number of medications and potential adverse effects in a large cohort of patients with COPD. The analysis was performed in 2741 patients of the German COPD cohort COSYCONET, using baseline data (visit 1) and follow-up data after about 1.5 years (visit 3). Spirometric GOLD grades 1-4 were found in 8/35/32/9% of patients and GOLD groups ABCD in 7/25/4/48% of patients, while the remaining patients (n = 450, 16.4%) could not be classified according to GOLD criteria. The compatibility of medication with age was evaluated via the PRISCUS list, drug interactions via the AiD clinic system, whereby only drug combinations occurring in at least 10 patients were considered (nine unwanted interactions, one wanted interaction). The median numbers of medications were 5 or more in all patient categories, among them 3 or more non-respiratory medications. In the total population there were 153 patients (10.2%) aged ≥65 years who had any medication of the PRISCUS list with intermediate or low risk. Serious adverse combinations of drugs according to AiD occurred in 114 patients (4.2%), while the number of unwanted but only potentially clinically relevant combinations was 175 (6.4%). The number of wanted combinations was 219 (8.0%). These numbers did not markedly change when restricting the analysis to patients of GOLD grades 1-4. Moreover, the results were similar for visit 1 and visit 3. We conclude that in a large cohort of COPD patients about 10% of patients aged at least 65 years had medications that could interfere with their age and that the proportions of patients with either unwanted or wanted drug interactions were both in the range of 8-10%. These results suggest that problems arising from the high number of medications were not very frequent in the COPD cohort analysed.

Effect of Chronic Kidney Diseases on Mortality among Digoxin Users Treated for Non-Valvular Atrial Fibrillation: A Nationwide Register-Based Retrospective Cohort Study

PURPOSE

This study investigated the impact of chronic kidney disease on all-causes and cardiovascular mortality in patients with atrial fibrillation treated with digoxin.

METHODS

All patients with non-valvular atrial fibrillation and/or atrial flutter as hospitalization diagnosis from January 1, 1997 to December 31, 2012 were identified in Danish nationwide administrative registries. Cox proportional hazard model was used to compare the adjusted risk of all-causes and cardiovascular mortality among patients with and without chronic kidney disease and among patients with different chronic kidney disease stages within 180 days and 2 years from the first digoxin prescription.

RESULTS

We identified 37,981 patients receiving digoxin; 1884 patients had the diagnosis of chronic kidney disease. Cox regression analysis showed no statistically significant differences in all-causes (Hazard Ratio, HR 0.89; 95% confident interval, CI 0.78-1.03) and cardiovascular mortality (HR 0.88; 95%CI 0.74-1.05) among patients with and without chronic kidney disease within 180 days of follow-up period. No statistically significant differences was found using a 2 years follow-up period neither for all causes mortality (HR 0.90; 95%CI 0.79-1.03), nor for cardiovascular mortality (HR 0.87; 95%CI 0.74-1.02). No statistically significant differences was found comparing patients with and without estimated Glomerular Filtration Rate <30ml/min/1.73m2 and patients with different stages of chronic kidney disease, for all-causes and cardiovascular mortality within 180 days and 2 years from the first digoxin prescription.

CONCLUSIONS

This study suggest no direct effect of chronic kidney disease and chronic kidney disease stages on all-causes and cardiovascular mortality within both 180 days and 2 years from the first digoxin prescription in patients treatment-naïve with digoxin for non-valvular atrial fibrillation.

Risk of psychiatric disorders in patients with chronic insomnia and sedative-hypnotic prescription: a nationwide population-based follow-up study

STUDY OBJECTIVES

Previous epidemiological studies have established insomnia as a major risk factor for mood, anxiety, and substance use disorders. However, the associations between insomnia with sedative-hypnotic prescriptions and various psychiatric disorders have not been thoroughly examined. The current study involved evaluating the risk of psychiatric disorders, namely schizophrenia, mood, anxiety, somatoform, and substance-related disorders, over a 6-y follow-up period in three groups: patients with insomnia and sedative-hypnotic prescriptions (Inso-Hyp), those with insomnia and without sedative-hypnotic prescriptions (Inso-NonHyp), and those with neither insomnia nor sedative-hypnotic prescriptions (NonInso-NonHyp).

METHODS

We used a historical cohort study design to compare the risk of psychiatric disorders among the three groups. Data regarding these patients were derived from reimbursement claims recorded in Taiwan's National Health Insurance Research Database. Cox proportional hazards regression was used to compare the 6-y risk of subsequent psychiatric disorders among the Inso-Hyp, Inso-NonHyp, and NonInso-NonHyp groups.

RESULTS

Compared with the Inso-NonHyp and NonInso-NonHyp group patients, the Inso-Hyp group patients exhibited a higher risk of psychiatric disorders, particularly bipolar disorders (adjusted hazard ratio [AHR]: 7.60; 95% confidence interval [CI]: 5.31-10.89 and AHR: 14.69; 95% CI: 11.11-19.43, respectively). Moreover, among the Inso-Hyp patient group, insomnia prescribed with benzodiazepine, a longer duration of sedative-hypnotic action, and higher doses of sedativehypnotics were significantly associated with a higher risk of depressive and anxiety disorders.

CONCLUSION

The Inso-Hyp group exhibited a higher risk of developing psychiatric disorders than did the Inso-NonHyp and NonInso-NonHyp groups. The results regarding patients with insomnia and sedative-hypnotic prescriptions associated with the risk of psychiatric disorders can serve as a reference for care providers when managing sleep disturbances.

Would It Matter to Expose Elderly Patients Who Took Digoxin to Chinese Medications?

OBJECTIVES

Elderly patients seem vulnerable to digoxin toxicity because of their diminished organ functions and tendency to encounter drug interactions. The aim of this research was to explore the extent of the concurrent use of digoxin with Chinese medications (CMs), its contributing factors, and the relevant consequences.

METHODS

A retrospective population-based cohort study was conducted using Longitudinal Health Insurance databases in Taiwan. Those elderly patients being prescribed with digoxin in outpatient settings in 2006 were evaluated for the incidence, prevalence, and duration of concurrent use with concentrated CMs in 2006. After 1:1 random matching to select the corresponding digoxin-only elderly users, univariate and multivariate logistic regression analyses were performed to explore factors associated with concomitant incident digoxin-CM use and incident digoxin-specific CM use. The relevant clinical and economic outcomes for a 3-month follow-up period from the initial exposure of incident digoxin-CM use were compared.

RESULTS

Of 185,076 elderly, 6,374 were prescribed with digoxin and 789 were CM-digoxin users in 2006. The prevalence and incidence of concomitant CM use among digoxin elderly users were 0.43% and 0.22%, respectively. Although the other factors were not statistically significantly associated with incident CM-digoxin use, patients with heart diseases and with benign prostate hypertrophy had an increased likelihood of incident CM-digoxin use of 115% and 102%, respectively. Almost all the concerned clinical and economic outcomes were not statistically significantly different between incident exposure or not, except for the use of potassium-sparing and nonsteroidal anti-inflammatory drugs.

CONCLUSIONS

There was a relatively low incidence of digoxin-CM use among the elderly in Taiwan. Although no significant effects on clinical and economic outcomes occurred, it is necessary to monitor potential side effects of digoxin more aggressively for those vulnerable elderly using digoxin with CMs, especially for those who tended to expose to incident digoxin-CM use elderly patients.

Exposure to sennoside-digoxin interaction and risk of digoxin toxicity: a population-based nested case-control study

AIMS

Digoxin is an important medication for heart failure (HF) patients and sennosides are widely used to treat constipation. Recently, safety concerns have been raised about a possible interaction between sennosides and digoxin, an issue that has not been studied empirically. This study therefore aimed to evaluate whether exposure to sennoside-digoxin interaction is associated with an increased risk of digoxin toxicity.

METHODS AND RESULTS

This was a population-based nested case-control study that analysed data obtained from the Taiwan National Health Insurance Research Database between 1 January 2001 and 31 December 2004. All HF patients treated with digoxin for the first time were included as the study cohort. Of these, cases were identified as subjects hospitalized for digoxin toxicity (International Classification of Diseases, Ninth Revision, Clinical Modification, ICD-9-CM 972.1), and matched to randomly selected controls. Use of sennosides was compared between the two groups. Odds ratios (ORs) were employed to quantify the risk associated with exposure to sennoside-digoxin interaction by conditional logistic regression. The study cohort comprised 222,527 HF patients, of whom 524 were identified as cases and 2,502 as matched controls. Use of sennosides during the 14 days preceding the index date was found to be associated with a 1.61-fold increased risk of digoxin toxicity [95% confidence interval (CI) = 1.15, 2.25]. Additionally, a greater risk was observed for sennosides prescribed at an average daily dose ≥ 24 mg (adjusted OR = 1.93; 95% CI = 1.27, 2.94).

CONCLUSION

The combined use of sennosides and digoxin was found to be associated with a modest increased risk of digoxin toxicity in HF patients.