Acute renal failure and interstitial nephritis in a patient treated with rofecoxib: case report and review of the literature

Drug-induced nephropathies

Drugs are associated frequently with the development of various types of acute and chronic kidney diseases. Nephrotoxicity is associated most commonly with injury in the tubulointerstitial compartment manifested as either acute tubular injury or acute interstitial nephritis. A growing number of reports has also highlighted the potential for drug-induced glomerular disease, including direct cellular injury and immune-mediated injury. Recognition of drug-induced nephropathies and rapid discontinuation of the offending agents are critical to maximizing the likelihood of renal function recovery. This review will focus on the pathology and pathogenesis of drug-induced acute interstitial nephritis and drug-induced glomerular diseases.

Inadequate drug prescription and the rise in drug-induced acute tubulointerstitial nephritis incidence

Drugs are a frequent cause of acute tubulointerstitial nephritis (ATIN). Antibiotics, non-steroidal anti-inflammatory drugs and recently proton pump inhibitors stand among the most commonly responsible ones. However, their respective responsibility is not well known. This study reports 33 cases of drug-induced ATIN (DI-ATIN), the most frequent ones being metamizole and omeprazole. Clinicians often fail to diagnose DI-ATIN because its signs and symptoms are non-specific and differ from the now classic form observed with methicillin. Furthermore, drugs causing ATIN are too often prescribed unnecessarily. This study shows that in more than one-fifth of our cases, ATIN complicated prescription of a drug that was not justified by an adequate clinical indication. The consequences were noxious for the patients and costly in terms of public health expenses.

Drug-induced acute interstitial nephritis

Acute interstitial nephritis (AIN) is a common cause of acute kidney injury. Many etiologies of AIN have been recognized--including allergic/drug-induced, infectious, autoimmune/systemic, and idiopathic forms of disease. The most common etiology of AIN is drug-induced disease, which is thought to underlie 60-70% of cases. Multiple agents from many different classes of drugs can cause AIN, and the clinical presentation and laboratory findings vary according to the class of drug involved. AIN is characterized by interstitial inflammation, tubulitis, edema, and in some cases, eventual interstitial fibrosis. A definitive diagnosis of AIN can be established only by kidney biopsy. Noninvasive tests such as (67)gallium scintigraphy and testing for eosinophiluria have limited diagnostic utility. The mainstay of therapy for drug-induced AIN is timely discontinuation of the causative agent. Although the benefits of corticosteroid therapy remain unproven, they do appear to have a positive effect in some patients with drug-induced AIN, especially when treatment is initiated early in the course of the disease. In general, the prognosis for drug-induced AIN is good, and at least partial recovery of kidney function is normally observed. Early recognition is crucial because patients can ultimately develop chronic kidney disease.

Cyclooxygenase-2 (PTGS2) inhibitors augment the rate of hexose transport in L6 myotubes in an insulin- and AMPKalpha-independent manner

AIMS/HYPOTHESIS

Some cyclooxygenase-2 (COX2, also known as prostaglandin-endoperoxide synthase 2 [PTGS2]) inhibitors have been shown to increase insulin sensitivity in man or induce hypoglycaemic episodes when overconsumed or taken in combination with oral hypoglycaemic drugs. These side-effects and their impact on patients are not always recognised in routine clinical practice. We investigated whether these side-effects of COX2 (PTGS2) inhibitors result from stimulation of the glucose transport system in skeletal muscle cells.

MATERIALS AND METHODS

L6 myotube cultures were used to study effects of COX2 (PTGS2) inhibitors on the glucose transport system and their relationship to PTGS2 expression, insulin action and AMP-activated protein kinase alpha (AMPKalpha) activity.

RESULTS

The inhibitors niflumic acid, nimesulide and rofecoxib increased the rate of hexose uptake in L6 myotubes in the absence of insulin and in a dose- and time-dependent manner. They did this by increasing the total cell content of member 4 of the solute carrier family 2 (SCLC2A4, previously known as glucose transporter 4 [GLUT4]) (but not SCLC2A1 [previously known as GLUT1]) mRNA and protein and the amount of it in the plasma membrane. AMPKalpha was not involved in the latter effect since the inhibitors did not activate it. In addition, none of the inhibitors modulated the rate of hexose transport in vascular endothelial and smooth muscle cells expressing PTGS2 and SCLC2A1. Prostaglandin-endoperoxide synthase 1 (also known as cyclooxygenase 1) inhibitors (acetylsalicylic acid and indomethacin) did not alter the rate of hexose uptake and SCLC2A4 subcellular distribution in L6 myotubes.

CONCLUSIONS/INTERPRETATION

This study suggests that certain COX2 (PTGS2) inhibitors can alter glucose homeostasis in vivo by stimulating glucose uptake in skeletal muscles that express PTGS2.

Drug-associated renal dysfunction and injury

Renal dysfunction and injury secondary to medications are common, and can present as subtle injury and/or overt renal failure. Some drugs perturb renal perfusion and induce loss of filtration capacity. Others directly injure vascular, tubular, glomerular and interstitial cells, such that specific loss of renal function leads to clinical findings, including microangiopathy, Fanconi syndrome, acute tubular necrosis, acute interstitial nephritis, nephrotic syndrome, obstruction, nephrogenic diabetes insipidus, electrolyte abnormalities and chronic renal failure. Understanding the mechanisms involved, and recognizing the clinical presentations of renal dysfunction arising from use of commonly prescribed medications, are important if injury is to be detected early and prevented. This article reviews the clinical features and basic processes underlying renal injury related to the use of common drugs.