Non-steroidal anti-inflammatory drugs and angiotensin converting enzyme inhibitors: a commonly prescribed combination with variable effects on renal function

Determining risk factors for triple whammy acute kidney injury

Concurrent use of a diuretic, a renin-angiotensin system (RAS) inhibitor, and a non-steroidal anti-inflammatory drug (NSAID) significantly increases the risk of acute kidney injury (AKI). This phenomenon is known as "triple whammy". Diuretics and RAS inhibitors, such as an angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blocker, are often prescribed in tandem for the treatment of hypertension, whereas some NSAIDs, such as ibuprofen, are available over the counter. As such, concurrent treatment with all three drugs is common. The goals of this study are to better understand the mechanisms underlying the development of triple whammy AKI and to identify physiological factors that may increase an individual's susceptibility. To accomplish these goals, we utilize sex-specific computational models of long-term blood pressure regulation. These models include variables describing the heart and circulation, kidney function, sodium and water reabsorption in the nephron and the RAS and are parameterized separately for men and women. Hypertension is modeled as overactive renal sympathetic nervous activity. Model simulations suggest that low water intake, the myogenic response, and drug sensitivity may predispose patients with hypertension to develop triple whammy-induced AKI. Triple treatment involving an ACE inhibitor, furosemide, and NSAID results in blood pressure levels similar to double treatment with ACEI and furosemide. Additionally, the male and female hypertensive models act similarly in most situations, except for the ACE inhibitor and NSAID double treatment.

Mechanisms of triple whammy acute kidney injury

Pre-renal acute kidney injury (AKI) results from glomerular haemodynamic alterations leading to reduced glomerular filtration rate (GFR) with no parenchymal compromise. Renin-angiotensin system inhibitors, such as angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor antagonists (ARAs), non-steroidal anti-inflammatory drugs (NSAIDs) and diuretics, are highly prescribed drugs that are frequently administered together. Double and triple associations have been correlated with increased pre-renal AKI incidence, termed "double whammy" and "triple whammy", respectively. This article presents an integrative analysis of the complex interplay among the effects of NSAIDs, ACEIs/ARAs and diuretics, acting alone and together in double and triple therapies. In addition, we explore how these drug combinations alter the equilibrium of regulatory mechanisms controlling blood pressure (renal perfusion pressure) and GFR to increase the odds of inducing AKI through the concomitant reduction of blood pressure and distortion of renal autoregulation. Using this knowledge, we propose a more general model of pre-renal AKI based on a multi whammy model, whereby several factors are necessary to effectively reduce net filtration. The triple whammy was the only model associated with pre-renal AKI accompanied by a course of other risk factors, among numerous potential combinations of clinical circumstances causing hypoperfusion in which renal autoregulation is not operative or is deregulated. These factors would uncouple the normal BP-GFR relationship, where lower GFR values are obtained at every BP value.

Incidence of acute kidney injury following total joint arthroplasty: a retrospective review by RIFLE criteria

Background

Total joint arthroplasty (TJA) is a common procedure with demand for arthroplasties expected to increase exponentially. Incidence of acute kidney injury (AKI) following TJA is reportedly low, with most studies finding an incidence of <2%, increasing to 9% when emergency orthopaedic patients are included.

Methods

Retrospective medical record review of consecutive primary, elective TJA procedures was undertaken at a large tertiary hospital (Alfred). Demographic, peri-operative and post-operative data were recorded. Factors associated with AKI (based on RIFLE criteria) were determined using multiple logistic regression.

Results

Between January 2011 and June 2013, 425 patients underwent TJA; 252 total knee replacements (TKR) and 173 total hip replacements (THR). Sixty-seven patients (14.8%) developed AKI, including 51 TKR. Factors associated with AKI (adjusting for known confounders) include increasing body mass index [adjusted odds ratio (AOR) 1.14; 95% CI: 1.07, 1.21], older age (AOR 1.07; 95% CI 1.02, 1.13) and lower pre-operative glomerular filtration rate (AOR 0.97; 95% CI 0.96, 0.99) and taking angiotensin-converting enzyme inhibitors (AOR 2.70; 95% CI 1.12, 6.48) and angiotensin-II receptor blockers (AOR 2.64; 95% CI 1.18, 5.93). In most patients, AKI resolved by discharge, however, only 62% of patients had renal function tests after discharge.

Conclusions

This study showed a rate of AKI of nearly 15% in our TJA population, substantially higher than previously reported. Given that AKI and long-term complications are associated, prospective research is needed to further understand the associated factors and predict those at risk of AKI. There may be opportunities to maximize the pre-operative medical management and mitigate risk.

Intravenous vasodilator therapy in congestive heart failure

The prevalence of congestive heart failure (CHF) is increasing in the US and worldwide, partly because patients are living longer. Treatment of CHF is mostly on an outpatient basis, but inpatient care is required for decompensated CHF, acute CHF or poor response to outpatient treatment. Control of symptoms is usually achieved by diuresis. Intravenous (IV) vasodilators are an important adjunct to the inpatient treatment of CHF. They work mainly by reducing the afterload on the myocardium although preload reduction also occurs. After clinical stabilisation, the goal is to switch to a maintenance oral regimen to be continued as outpatient therapy. The range of IV vasodilators available for inpatient treatment of CHF includes nitrates, phosphodiesterase inhibitors, dobutamine, morphine, ACE inhibitors, B-type natriuretic peptides and endothelin receptor antagonists. As each agent may have a different mechanism or site of action, each agent may affect preload, contractility or afterload to a different extent and it may be desirable to choose one over the other in a particular clinical setting. Examples of standard therapy include dobutamine, milrinone and nitroglycerin. Nesiritide, a B-type natriuretic peptide, is a newer vasodilator and US FDA approved for use in acute CHF. However, most studies with this agent have been in small numbers of patients with anecdotal findings. Larger studies are warranted to pinpoint the efficacy and adverse effects of this agent. It is primarily used to reduce the acuity of decompensated CHF on admission to hospital.Endothelin receptor antagonists show promise in the management of acute CHF, but continue to be investigational. Long-term data on their efficacy and safety are limited. None of the endothelin receptor antagonists are FDA approved for use in patients with CHF.

Nonsteroidal anti-inflammatory drugs and heart failure

Heart failure constitutes an increasing public health problem because of the growing incidence and prevalence, poor prognosis and high hospital (re)admission rates. Myocardial infarction is the underlying cause in the majority of patients, followed by hypertension, valvular heart disease and idiopathic cardiomyopathy. Nonsteroidal anti-inflammatory drugs (NSAIDs), which inhibit the enzymes cyclo-oxygenase (COX) 1 and 2, have been associated with the occurrence of symptoms of heart failure in several case reports and quantitative studies, mainly in patients with a history of cardiovascular disease or left ventricular impairment. NSAIDs may impair renal function in patients with a decreased effective circulating volume by inhibiting prostaglandin synthesis. Consequently, water and sodium retention, and decreases in renal blood flow and glomerular filtration rate may occur, affecting the unstable cardiovascular homeostasis in these patients. In patients with pre-existing heart failure, this may lead to cardiac decompensation. Putative renal-sparing NSAIDs, such as COX-2 selective inhibitors have similar effects on renal function as the traditional NSAIDs, and can likewise be expected to increase the risk of heart failure in susceptible patients. NSAIDs are frequently prescribed to elderly patients, who are particularly at risk for the renal adverse effects. If treatment with NSAIDs in high risk patients cannot be avoided, intensive monitoring and patient education is important.

Effects of long-term treatment with angiotensin-converting-enzyme inhibitors in the presence or absence of aspirin: a systematic review

BACKGROUND

Results from a retrospective analysis of the Studies of Left Ventricular Dysfunction (SOLVD) study suggest that angiotensin-converting-enzyme (ACE) inhibitors may be less effective in patients receiving aspirin. We aimed to confirm or refute this theory.

METHODS

We used the Peto-Yusuf method to undertake a systematic overview of data for 22060 patients from six long-term randomised trials of ACE inhibitors to assess whether aspirin altered the effects of ACE inhibitor therapy on major clinical outcomes (composite of death, myocardial infarction, stroke, hospital admission for congestive heart failure, or revascularisation).

FINDINGS

Baseline characteristics, and prognosis in patients allocated placebo, differed strikingly between those who were and were not taking aspirin at baseline. Results from analyses of all trials, except SOLVD, did not suggest any significant differences between the proportional reductions in risk with ACE inhibitor therapy in the presence or absence of aspirin for the major clinical outcomes (p=0.15), or in any of its individual components, except myocardial infarction (interaction p=0.01). Overall, ACE inhibitor therapy significantly reduced the risk of the major clinical outcomes by 22% (p<0.0001), with clear reductions in risk both among those receiving aspirin at baseline (odds ratio 0.80, [99% CI 0.73-0.88]) and those who were not (0.71 [99% CI 0.62-0.81], interaction p=0.07).

INTERPRETATION

Considering the totality of evidence on all major vascular outcomes in these trials, there is only weak evidence of any reduction in the benefit of ACE-inhibitor therapy when added to aspirin. However, there is definite evidence of clinically important benefits with respect to these major clinical outcomes with ACE-inhibitor therapy, irrespective of whether concomitant aspirin is used.

Clinical effects of early angiotensin-converting enzyme inhibitor treatment for acute myocardial infarction are similar in the presence and absence of aspirin: systematic overview of individual data from 96,712 randomized patients. Angiotensin-converting Enzyme Inhibitor Myocardial Infarction Collaborative Group

OBJECTIVES

We sought to determine whether the clinical effects of early angiotensin-converting enzyme (ACE) inhibitor (ACEi) treatment for acute myocardial infarction (MI) are influenced by the concomitant use of aspirin (ASA).

BACKGROUND

Aspirin and ACEi both reduce mortality when given early after MI. Aspirin inhibits the synthesis of vasodilating prostaglandins, and, in principle, this inhibition might antagonize some of the effects of ACEi. But it is uncertain whether, in practice, this influences the effects of ACEi on mortality and major morbidity after MI.

METHODS

This overview sought individual patient data from all trials involving more than 1,000 patients randomly allocated to receive ACEi or control starting in the acute phase of MI (0-36 h from onset) and continuing for four to six weeks. Data on concomitant ASA use were available for 96,712 of 98,496 patients in four eligible trials (and for none of 1,556 patients in the one other eligible trial).

RESULTS

Overall 30-day mortality was 7.1% among patients allocated to ACEi and 7.6% among those allocated to control, corresponding to a 7% (standard deviation [SD], 2%) proportional reduction (95% confidence interval 2% to 11%, p = 0.004). Angiotensin-converting enzyme inhibitor was associated with similar proportional reductions in 30-day mortality among the 86,484 patients who were taking ASA (6% [SD, 3%] reduction) and among the 10,228 patients who were not (10% [SD, 5%] reduction: chi-squared test of heterogeneity between these reductions = 0.4; p = 0.5). Angiotensin-converting enzyme inhibitor produced definite increases in the incidence of persistent hypotension (17.9% ACEi vs. 9.4% control) and of renal dysfunction (1.3% ACEi vs. 0.6% control), but there was no good evidence that these effects were different in the presence or absence of ASA (chi-squared for heterogeneity = 0.4 and 0.0, respectively; both not significant). Nor was there good evidence that the effects of ACEi on other clinical outcomes were changed by concomitant ASA use.

CONCLUSIONS

Both ASA and ACEi are beneficial in acute MI. The present results support the early use of ACEi in acute MI, irrespective of whether or not ASA is being given.

Drug-induced heart failure

Heart failure is a clinical syndrome that is predominantly caused by cardiovascular disorders such as coronary heart disease and hypertension. However, several classes of drugs may induce heart failure in patients without concurrent cardiovascular disease or may precipitate the occurrence of heart failure in patients with preexisting left ventricular impairment. We reviewed the literature on drug-induced heart failure, using the MEDLINE database and lateral references. Successively, we discuss the potential role in the occurrence of heart failure of cytostatics, immunomodulating drugs, antidepressants, calcium channel blocking agents, nonsteroidal anti-inflammatory drugs, antiarrhythmics, beta-adrenoceptor blocking agents, anesthetics and some miscellaneous agents. Drug-induced heart failure may play a role in only a minority of the patients presenting with heart failure. Nevertheless, drug-induced heart failure should be regarded as a potentially preventable cause of heart failure, although sometimes other priorities do not offer therapeutic alternatives (e.g., anthracycline-induced cardiomyopathy). The awareness of clinicians of potential adverse effects on cardiac performance by several classes of drugs, particularly in patients with preexisting ventricular dysfunction, may contribute to timely diagnosis and prevention of drug-induced heart failure.

Role of bradykinin in the neonatal renal effects of angiotensin converting enzyme inhibition

The vascular effects of angiotensin converting enzyme inhibitors are mediated by the inhibition of the dual action of angiotensin converting enzyme (ACE): production of angiotensin II and degradation of bradykinin. The deleterious effect of converting enzyme inhibitors (CEI) on neonatal renal function have been ascribed to the elevated activity of the renin-angiotensin system. In order to clarify the role of bradykinin in the CEI-induced renal dysfunction of the newborn, the effect of perindoprilat was investigated in anesthetized newborn rabbits with intact or inhibited bradykinin B2 receptors. Inulin and PAH clearances were used as indices of GFR and renal plasma flow, respectively. Perindoprilat (20 microg/kg i.v.) caused marked systemic and renal vasodilation, reflected by a fall in blood pressure and renal vascular resistance. GFR decreased, while urine flow rate did not change. Prior inhibition of the B2 receptors by Hoe 140 (300 microg/kg s.c.) did not prevent any of the hemodynamic changes caused by perindoprilat, indicating that bradykinin accumulation does not contribute to the CEI-induced neonatal renal effects. A control group receiving only Hoe 140 revealed that BK maintains postglomerular vasodilation via B2 receptors in basal conditions. Thus, the absence of functional B2 receptors in the newborn was not responsible for the failure of Hoe 140 to prevent the perindoprilat-induced changes. Species- and/or age-related differences in the kinin-metabolism could explain these results, suggesting that in the newborn rabbit other kininases than ACE are mainly responsible for the degradation of bradykinin.

Adverse cardiovascular effects of NSAIDs in patients with congestive heart failure

Congestive heart failure (CHF) is a complex clinical syndrome, especially in the elderly, which results from cardiac dysfunction. Epidemiological studies have shown a gradual increase in age-adjusted hospitalisation rates for CHF and overall population prevalence of CHF during the last 2 decades in Western countries. The healthcare costs associated with CHF are considerable and are likely to increase in the near future. Hence, identification of risk factors which could induce or exacerbate CHF is of major importance. NSAIDs are frequently prescribed in elderly patients for several rheumatological and nonrheumatological indications. Numerous adverse reactions, mainly related to the gastrointestinal tract and kidney function, have been described for NSAIDs. In addition, some case reports have suggested a causal relation between the use of NSAIDs and the onset of CHF. The pathophysiology of CHF and the pharmacological properties of NSAIDs support this hypothesis. In particular, the inhibition of prostaglandin synthesis may adversely affect cardiovascular homeostasis in patients with a propensity to develop CHF. Notwithstanding the adverse effects, however, the prescription of NSAIDs in elderly patients is often desirable and justifiable. Therefore, further pharmaco-epidemiological research is needed to quantify the risk for CHF attributable to the use of NSAIDs and to identify patients who are particularly susceptible to the adverse cardiovascular effects of these agents. In these patients, it may be advisable to avoid the use of NSAIDs.

Tiaprofenic acid. A reappraisal of its pharmacological properties and use in the management of rheumatic diseases

Tiaprofenic acid is a nonsteroidal anti-inflammatory drug (NSAID) used in the treatment of patients with rheumatic diseases and other clinical conditions of pain and inflammation. Like other propionic acid derivatives, tiaprofenic acid is effective and generally well tolerated. Comparative studies in patients with rheumatoid arthritis or osteoarthritis receiving tiaprofenic acid 600 mg/day demonstrated improvements in pain intensity, duration of morning stiffness, articular index and other clinical variables which were similar to those achieved with alternative NSAIDs. Tolerability was also comparable between tiaprofenic acid and other NSAIDs in most trials; the most frequently reported adverse events involved the gastrointestinal tract. Some studies showed a trend towards fewer patient withdrawals because of adverse events with tiaprofenic acid than with NSAIDs such as indomethacin. Current evidence suggests that nonbacterial cystitis is more likely to be associated with tiaprofenic acid than with other NSAIDs. This reaction should, however, be considered in the perspective of its infrequent occurrence and its typical reversibility, and against the wider background of the established usage of tiaprofenic acid and its overall tolerability profile which is similar to that of other NSAIDs. Unlike indomethacin, tiaprofenic acid was not associated with increased cartilage degradation in a recently completed large clinical trial known as LINK, which evaluated the effects of long term administration in patients with osteoarthritis of the knee. Thus, tiaprofenic acid is an established option among the range of NSAIDs used in the treatment of patients with rheumatic diseases, with efficacy and tolerability profiles that are relatively well characterised. The availability of a sustained release dosage form of tiaprofenic acid, which has a similar efficacy and tolerability profile to the standard formulation, provides a convenient once daily dosage regimen.

The effect of tenidap on the anti-hypertensive efficacy of ACE inhibitors in patients treated for mild to moderate hypertension

1. A randomised, placebo controlled, double-blind, parallel group study was conducted to assess the effect of tenidap sodium, a novel cytokine modulating drug, on the stable hypotensive response to the angiotension converting enzyme (ACE) inhibitor enalapril in subjects with mild to moderate, uncomplicated, essential hypertension. 2. Twenty-four male and female hypertensives, aged 33-77 years, received either 120 mg tenidap sodium or matched placebo daily for 22 days concomitantly with enalapril. 3. Mean endpoint supine and standing, systolic and diastolic pressures remained within 10% of baseline in each treatment group. However, the endpoint values were marginally above baseline during double-blind treatment with tenidap and marginally below baseline in the group receiving placebo. The increases in supine and standing systolic pressures in the tenidap group differed significantly from the changes in the placebo group. There were no significant differences between groups in changes in pulse rate. 4. Gastrointestinal side effects of mild to moderate severity attributed to treatment with tenidap were experienced by five subjects, one of whom was withdrawn during the third week of treatment. One subject receiving placebo was withdrawn because of a moderate headache attributed to study treatment. 5. The results of this study suggest that treatment with tenidap may interfere with the anti-hypertensive efficacy of ACE inhibitors. It is recommended that blood pressure should be monitored when tenidap is administered concomitantly with an ACE inhibitor.