Enhancement of blood glucose lowering effect of a sulfonylurea when coadministered with an ACE inhibitor: results of a glucose-clamp study

An Overview of Clinically Imperative and Pharmacodynamically Significant Drug Interactions of Renin-Angiotensin-Aldosterone System (RAAS) Blockers

INTRODUCTION

Hypertension is a leading cause of cardiovascular disease and chronic kidney disease, resulting in premature death and disability. The Renin-Angiotensin-Aldosterone System (RAAS) blockers, including Angiotensin-Converting Enzyme (ACE) inhibitors or Angiotensin Receptor Blockers (ARBs), are used as first-line antihypertensive therapy to treat hypertensive patients with comorbidities, including diabetes, ischemic heart disease, heart failure, and chronic kidney disease. The use of RAS blockers is associated with the risks, such as hyperkalemia, angioedema, etc. The drugs potentiating them interact pharmacodynamically, resulting in adverse consequences. This review article focuses on the clinically important drug interactions of RAAS blockers.

MATERIALS AND METHODS

The electronic databases, such as Medline/PubMed Central/PubMed, Google Scholar, ScienceDirect, Cochrane Library, Directory of Open Access Journals (DOAJ), Embase, and reference lists were searched to identify relevant articles.

RESULTS

The risk of hyperkalemia may be enhanced potentially in patients receiving a RAS blocker and potassium-sparing diuretics, potassium supplements, trimethoprim, adrenergic betablockers, antifungal agents, calcineurin inhibitors, pentamidine, heparins or an NSAID, concomitantly. The patients taking ACE inhibitors and mTOR inhibitors, DPP4 inhibitors, alteplase, or sacubitril/valsartan concurrently may be at increased risk of developing angioedema.

CONCLUSION

Clinicians, pharmacists, and other healthcare practitioners should be accountable for medication safety. To avoid adverse implications, prescribers and pharmacists must be aware of the drugs that interact with RAAS blockers.

Angiotensin-Converting Enzyme Inhibitors Used Concomitantly with Insulin Secretagogues and the Risk of Serious Hypoglycemia

Serious hypoglycemia is a major adverse event associated with insulin secretagogues. Previous studies have suggested a potential relationship between angiotensin-converting enzyme inhibitors (ACEIs) used with sulfonylureas and serious hypoglycemia, and widely used drug compendia warn of this potential drug-drug interaction. We investigated the association between serious hypoglycemia and concomitant use of ACEIs in patients receiving insulin secretagogues, using the self-controlled case series design and Medicaid claims data from 5 US states linked to Medicare claims from 1999-2011. The exposure of interest was active prescription for ACEIs during insulin secretagogue or metformin (negative control object drug) episodes. The outcome was hospital presentation for serious hypoglycemia, identified by discharge diagnosis codes in inpatient and emergency department claims (positive predictive value ~ 78-89%). We calculated confounder-adjusted rate ratios (RRs) and 95% confidence internals (CIs) of outcome occurrence during ACEI-exposed vs. ACEI-unexposed time using conditional Poisson regression. The RRs for ACEIs were not statistically elevated during observation time of glipizide (RR, 1.06; CI, 0.98-1.15), glyburide (RR, 1.05; CI, 0.96-1.15), repaglinide (RR, 1.15; CI, 0.94-1.41), or metformin (RR, 1.02; CI, 0.97-1.06); but was modestly elevated with glimepiride (RR, 1.23; CI, 1.11-1.37) and modestly reduced with nateglinide (RR, 0.73; CI, 0.56-0.96). The overall pattern of results do not suggest that ACEIs used with insulin secretagogues were associated with increased rates of serious hypoglycemia, with the possible exception of glimepiride.

Interdisciplinary approach to compensation of hypoglycemia in diabetic patients with chronic heart failure

Diabetes mellitus is a chronic disease requiring lifelong control with hypoglycemic agents that must demonstrate excellent efficacy and safety profiles. In patients taking glucose-lowering drugs, hypoglycemia is a common cause of death associated with arrhythmias, increased thrombus formation, and specific effects of catecholamines due to sympathoadrenal activation. Focus is now shifting from merely glycemic control to multifactorial approach. In the context of individual drugs and classes, this article reviews interdisciplinary strategies evaluating metabolic effects of drugs for treatment of chronic heart failure (CHF) which can mask characteristic hypoglycemia symptoms. Hypoglycemia unawareness and cardiac autonomic neuropathy are discussed. Data suggesting that hypoglycemia modulates immune response are reviewed. The potential role of gut microbiota in improving health of patients with diabetes and CHF is emphasized. Reports stating that nondiabetic CHF patients can have life-threatening hypoglycemia associated with imbalance of thyroid hormones are discussed. Regular glycemic control based on HbA1c measurements and adequate pharmacotherapy remain the priorities in diabetes management. New antihyperglycemic drugs with safer profiles should be preferred in vulnerable CHF patients. Multidrug interactions must be considered. Emerging therapies with reduced hypoglycemia risk, telemedicine, sensor technologies, and genetic testing predicting hypoglycemia risk may help solving the challenges of hypoglycemia in CHF patients with diabetes. Interdisciplinary work may involve cardiologists, diabetologists/endocrinologists, immunologists, gastroenterologists, microbiologists, nutritionists, imaging specialists, geneticists, telemedicine experts, and other relevant specialists. This review emphasizes that systematic knowledge on pathophysiology of hypoglycemia in diabetic patients with CHF is largely lacking and the gaps in our understanding require further discoveries.

Pharmacotherapy of type 2 diabetes mellitus: an update on drug-drug interactions

The incidence of type 2 diabetes mellitus is increasing rapidly, as are the associated co-morbidities. Consequently, it has become necessary for a diabetic patient to take multiple medications at the same time to delay progression of the disease. This can put patients at an increased risk of moderate to severe drug interactions, which may threaten patients' life or may deteriorate the quality of their life. Hence, managing drug-drug interactions is the cornerstone of anti-diabetic therapy. Most of the clinically important drug-drug interactions of anti-diabetic agents are related to their metabolic pathways, but drugs that compete for renal excretion or impair renal status can also play an important role. In this review, we have examined the clinical implications and underlying mechanisms of drugs that are likely to alter the pharmacologic response of or cause adverse events with antidiabetic drugs, and we have outlined safe and efficacious treatment modalities.

Angiotensin-converting enzyme insertion/deletion polymorphism and severe hypoglycemia complicating type 2 diabetes: the Fremantle Diabetes Study

AIMS/HYPOTHESES

The aim of this study was to determine whether the angiotensin-converting enzyme (ACE) gene I/D polymorphisms independently predict severe hypoglycemia in community-dwelling type 2 patients.

METHODS

Six hundred and two patients who were ACE genotyped at baseline and assessed in 1998 were followed up to the end of June 2006. Severe hypoglycemia was defined as that requiring documented health service use as the primary diagnosis. Cox proportional hazards modeling was used to determine the predictors of first episode and zero-inflated negative binomial regression modeling identified predictors of frequency.

RESULTS

Forty-nine patients (8.1%) experienced 63 episodes of severe hypoglycemia. After adjusting for previously identified significant independent predictors of time to first episode, both ACE DD genotype and ACE inhibitor therapy, but not their interaction, added to the model [hazard ratio (95% confidence interval): 2.34 (1.29-4.26), P = 0.006, and 1.77 (0.99-3.13), P = 0.052, respectively]. Similarly, after adjusting for previously identified risk factors for multiple episodes of severe hypoglycemia, ACE DD genotype was independently associated with increased risk [incidence relative risk (95% confidence interval): 1.80 (1.00-3.24), P = 0.050].

CONCLUSIONS/INTERPRETATION

ACE DD genotype was associated with an approximately 2-fold increased risk of the first episode of severe hypoglycemia and its subsequent frequency in well-characterized patients with type 2 diabetes. Consistent with previous case-control studies, ACE inhibitor therapy was a weak predictor of severe hypoglycemia. ACE I/D genotyping might provide useful adjunctive prognostic information when intensive glycemic control measures are contemplated.

Drug-induced hypoglycaemia: an update

Drugs are the most frequent cause of hypoglycaemia in adults. Although hypoglycaemia is a well known adverse effect of antidiabetic agents, it may occasionally develop in the course of treatment with drugs used in everyday clinical practice, including NSAIDs, analgesics, antibacterials, antimalarials, antiarrhythmics, antidepressants and other miscellaneous agents. They induce hypoglycaemia by stimulating insulin release, reducing insulin clearance or interfering with glucose metabolism. Several drugs may also potentiate the hypoglycaemic effect of antidiabetic agents. Administration of these agents to individuals with diabetes mellitus is of most concern. Many of these drugs, and depending on clinical setting, may also induce hyperglycaemia. Drug-induced hepatotoxicity and nephrotoxicity may lead in certain circumstances to hypoglycaemia. Some drugs may also induce hypoglycaemia by causing pancreatitis. Drug-induced hypoglycaemia is usually mild but may be severe. Effective clinical management can be handled through awareness of this drug-induced adverse effect on blood glucose levels. Herein, we review pertinent clinical information on the incidence of drug-induced hypoglycaemia and discuss the underlying pathophysiological mechanisms, and prevention and management.

Characteristics of patients with sulphonurea-induced hypoglycemia

BACKGROUND/AIM

Sulphonylurea (SU) agents continue to be a cornerstone of the therapy of type 2 diabetes mellitus (T2DM). Hypoglycemia is the most dangerous side effect of SU. Identifying the characteristics of patients with SU-induced hypoglycemia (SUIH) may help in reducing its frequency.

METHODS

All consecutive admissions of patients with SUIH, between 2000 and 2008, were retrospectively reviewed.

RESULTS

Over the study period, 4702 patients with type 2 diabetes mellitus were admitted to the department of medicine. Of these, 155 patients were admitted because of SUIH. Most of these patients were elderly, had multiple comorbid situations, and were taking multiple medications. Almost a third of the patients had a history of recent changes in the use of their medications. Various infectious complications (urinary, lung, skin, and peritoneal) occurred in 43% of patients. Renal failure was a frequent finding at admission (44% of patients had creatinine plasma levels > 120 μmol/L). Poor oral intake before admission was reported by 31% of patients. Markers of malnutrition (low serum levels of albumin, iron, vitamin B-12, and folic acid) were frequently found in most patients. Mean hemoglobin A1C levels were in the low abnormal levels. A major vascular event during hospitalization co-occurred in 11% of patients. Three patients died during the hospital admission for SUIH.

CONCLUSIONS

Elderly fragile patients with multiple comorbid situations including renal failure and tight glycemic control are prone to develop SUIH. Sulphonylurea agents should be avoided in such patients. An episode of SUIH should be considered as an alarming prognostic marker.

Key considerations around the risks and consequences of hypoglycaemia in people with type 2 diabetes

Hypoglycaemia and its consequences represent a significant risk for many people who have type 2 diabetes, and hypoglycaemia is currently under-recognised and commonly avoidable. Current clinical guidelines recommend the targeting of tight glycaemic control and this strategy may also be associated with an increased risk of hypoglycaemia. Hypoglycaemia impacts on morbidity, mortality and quality of life of people with type 2 diabetes, and improved recognition of the symptoms of hypoglycaemia will allow effective treatment and reduce the risk of progression to more severe episodes. A common cause of hypoglycaemia in people with type 2 diabetes is glucose-lowering medication, in particular, those which raise insulin independently of ambient glucose concentration such as sulphonylureas and exogenous insulin. The recently published National Institute for Health and Clinical Excellence guideline recommends the use of Dipeptidyl peptidase-4 inhibitors or thiazolidinediones (glitazones) as alternative second-line therapy instead of a sulphonylurea in those patients who are at significant risk of hypoglycaemia and its consequences.

Therapeutic perspective: starting an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker in a diabetic patient

There are extensive data confirming involvement of the renin-angiotensin system in microvascular and macrovascular complications of diabetes. Blockade of the system with angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) is regarded as the first-line approach to managing hypertension and end-organ protection in patients with diabetes. ACE inhibitors are still the preferred agents for most patients. Dose should be lower with renal impairment unless an agent which is not excreted by the kidneys is chosen. Dose should be titrated up to the maximum tolerated to optimize end-organ protection, and intermediate-acting agents should be given in a twice daily divided dose when higher doses are used. Electrolytes should be checked before commencing, 1-2 weeks later, and after each dose increment. A modest decrease in estimated glomerular filtration rate (eGFR) and increase in creatinine often occurs with ACE inhibitors or ARBs. The agents may need to be discontinued if eGFR decreases by >15%, if creatinine increases by >20%, or if hyperkalemia develops. Cough occurs in 5-10% of patients taking ACE inhibitor, but not with ARBs. Angioedema is probably equally common with ACE inhibitor or ARBs. It is not widely appreciated that ACE inhibitors may precipitate hypoglycaemia in patients taking glucose-lowering medication. The combination of ACE inhibitor and ARB is not routinely indicated for either hypertension or end-organ protection. While patients should not be denied the undoubted benefits of these important classes of drugs, we should also guard against their indiscriminate use in patients with diabetes. We must also ensure that patients receive appropriate counselling and monitoring.

Development of an evidence-based checklist for the detection of drug related problems in type 2 diabetes

Objective To develop an evidence-based checklist to identify potential drug related problems (PDRP) in patients with type 2 diabetes. Setting The evidence based checklist was applied to records of ambulatory type 2 diabetes patients in New South Wales, Australia. Method After comprehensive review of the literature, relevant medication groups and potential drug related problems in type 2 diabetes were identified. All the relevant information was then structured in the form of a checklist. To test the utility of the evidence-based checklist a cross-sectional retrospective study was conducted. The PDRP checklist was applied to the data of 148 patients with established type 2 diabetes and poor glycaemic control. The range and extent of DRPs in this population were identified, which were categorized using the PCNE classification. In addition, the relationship between the total as well as each category of DRPs and several of the patients’ clinical parameters was investigated. Main outcome measure: Number and category of DRPs per patient. Results The PDRP checklist was successfully developed and consisted of six main sections. 682 potential DRPs were identified using the checklist, an average of 4.6 (SD = 1.7) per patient. Metabolic and blood pressure control in the study subjects was generally poor: with a mean HbA1c of 8.7% (SD = 1.5) and mean blood pressure of 139.8 mmHg (SD = 18.1)/81.7 mmHg (SD = 11.1). The majority of DRPs was recorded in the categories ‘therapy failure’ (n = 264) and ‘drug choice problem’ (n = 206). Potentially non-adherent patients had a significantly higher HbA1c than patients who adhered to therapy (HbA1c of 9.4% vs. 8.5%; P = 0.01). Conclusion This is the first tool developed specifically to detect potential DRPs in patients with type 2 diabetes. It was used to identify DRPs in a sample of type 2 diabetes patients and demonstrated the high prevalence of DRPs per patient. The checklist may assist pharmacists and other health care professionals to systematically identify issues in therapy and management of their type 2 diabetes patients and enable earlier intervention to improve metabolic control.