Renal syndromes associated with nonsteroidal antiinflammatory drugs

Analgesic effect of sustained-release flurbiprofen administered at the site of tissue injury in the oral surgery model

Nonsteroidal anti-inflammatory drugs produce their analgesic and adverse effects through interaction with cyclooxygenase in a variety of tissues. The authors evaluated the therapeutic potential of administering a sustained-release formulation of flurbiprofen into a surgical wound following oral surgery to produce analgesia at the site of injury while minimizing exposure to potential targets for toxicity. Subjects (N = 98) received 1 of 8 treatments: flurbiprofen in a microparticle formulation in doses of 3.125 mg, 6.25 mg, 12.5 mg, 25 mg, or 50 mg; PO flurbiprofen 25 mg or 50 mg; or placebo. The flurbiprofen microparticle formulation or matching placebo was placed into the extraction sites at the end of surgery (removal of 2 lower impacted third molars). The sum of the pain visual analog scale over the 6-hour observation period demonstrated significantly less pain (P < .05) for flurbiprofen microparticle in comparison with placebo. Fewer subjects remedicated in the flurbiprofen microparticle drug groups, primarily for the 12.5-mg and higher doses. The incidence of adverse effects and local complications did not differ across groups. These data suggest that direct administration of flurbiprofen in a microparticle formulation at a site of tissue injury delays the onset and lowers the intensity of postoperative pain at lower doses than usually administered orally.

Efficacy and renal tolerability of ibuprofen vs. indomethacin in preterm infants with patent ductus arteriosus

Indomethacin is commonly used for the treatment of patent ductus arteriosus (PDA) but has renal failure as a main side-effect. Ibuprofen seems to be efficient in closing the ductus with less side-effects, but few studies are available in literature as regards its use in preterm infants. This study is a retrospective analysis of clinical data in order to compare the efficacy and the renal tolerability of ibuprofen and indomethacin administered to preterm infants with gestational age (GA) < or = 30 weeks for the treatment of PDA. From our data, ibuprofen results pharmacologically as efficient as indomethacin and could be an alternative in prematures. About renal tolerability, our data confirm that non-steroidal anti-inflammatory drugs treatment could affect at least transiently renal function. Moreover, indomethacin could be more nephrotoxic compared with ibuprofen, as creatinine concentrations normalize more slowly in this group, although the mean difference between the two drugs was not significant as our population sample was small. Further studies are needed to assess whether ibuprofen is really less nephrotoxic than indomethacin, in particular by examining carefully the correlation between GA and ibuprofen administration.

QSAR and classification models of a novel series of COX-2 selective inhibitors: 1,5-diarylimidazoles based on support vector machines

The support vector machine, which is a novel algorithm from the machine learning community, was used to develop quantitation and classification models which can be used as a potential screening mechanism for a novel series of COX-2 selective inhibitors. Each compound was represented by calculated structural descriptors that encode constitutional, topological, geometrical, electrostatic, and quantum-chemical features. The heuristic method was then used to search the descriptor space and select the descriptors responsible for activity. Quantitative modelling results in a nonlinear, seven-descriptor model based on SVMs with root mean-square errors of 0.107 and 0.136 for training and prediction sets, respectively. The best classification results are found using SVMs: the accuracy for training and test sets is 91.2% and 88.2%, respectively. This paper proposes a new and effective method for drug design and screening.

Albuminuria and tubular markers in juvenile idiopathic arthritis

This study investigates whether renal damage occurs in children with juvenile idiopathic arthritis (JIA) either secondary to the disease per se or due to the side effects of non-steroidal anti-inflammatory drugs (NSAIDs) and slow-acting anti-rheumatic drugs (SAARDs) used in treatment. In this cross-sectional study, albuminuria, N -acetyl glucosaminidase (NAG), beta(2)-microglobulin (beta(2)M), and creatinine (Cr) levels were measured in urine samples of 45 patients (23 female, 22 male, 9.4+/-3.9 years) with JIA and a sex- and age-matched control group of 33 healthy children. The urinary albumin/Cr, NAG/Cr, and beta(2)M/Cr ratios of children with JIA and of the control group did not differ statistically. No difference was noted between patient groups with different types of JIA (12 systemic, 18 polyarticular, and 15 oligoarticular JIA). JIA patients with active disease (n=16) had higher NAG/Cr values than patients with inactive disease (P=0.002). NAG/Cr levels correlated with erythrocyte sedimentation rate (r=0.66, P<0.001) and platelet count (r=0.61, P<0.001) and showed a slight correlation with the number of joints with active arthritis in children with polyarticular JIA (r=0.45, P=0.055). Neither beta(2)M/Cr nor albumin/Cr ratios were associated with disease activity. No difference was noted between patient groups treated with different NSAIDs and SAARDs. In children with JIA tubular enzymuria increases during the active phase of the disease; however, it seems that permanent renal damage does not occur.

Drug-induced renal failure: a focus on tubulointerstitial disease

Therapeutic agents induce acute renal failure (ARF) by promoting various types of injury to the kidney. Acute interstitial nephritis (AIN) develops from medications that incite an allergic reaction, leading to interstitial inflammation and tubular damage. Acute tubular necrosis (ATN) is a dose-dependent process that develops from direct toxicity on tubular epithelia, typically in the absence of inflammation. Additional, less common patterns of drug-induced renal injury include osmotic nephropathy, crystal nephropathy, and acute nephrocalcinosis. This review focuses on the multitude of patterns of drug-induced renal failure due to tubulointerstitial disease.

Effects of Long-Term Oral Administration of Ketoprofen in Clinically Healthy Beagle Dogs

To investigate the adverse effects of long-term administration of ketoprofen in dogs, ketoprofen (1 mg/kg) was administered to five clinically healthy beagle dogs (ketoprofen group) and gelatin capsules (control group) were administered to four clinically healthy beagle dogs for 30 days. We monitored the dogs through periodic physical examination, blood analyses, endoscopic examinations, fecal occult blood tests, renal function tests, urinalysis, urinary enzyme indices and cuticle bleeding time analysis. The lesions in the stomach, especially in the pyloric antrum, and fecal occult blood progressively worsened in the ketoprofen group. However, the differences between the ketoprofen group and the control group were not statistically significant. One dog in the ketoprofen group temporarily exhibited a decrease in renal plasma flow and two dogs exhibited enzymuria. However, these changes did not persist and the other examinations showed no significant difference between premedication and postmedication in the ketoprofen group. Therefore, the adverse effects of long-term administration of ketoprofen observed in this study were not clinically important in healthy dogs. Nevertheless, further investigation of adverse renal effects from long-term administration of ketoprofen is necessary in the dogs with subclinical renal disease.

Benefits of transdermal fentanyl in patients with rheumatoid arthritis or with osteoarthritis of the knee or hip: an open-label study to assess pain control

OBJECTIVES

To evaluate the effectiveness and safety of transdermal fentanyl (TDF) for the treatment of pain associated with rheumatoid arthritis (RA) or osteoarthritis of the knee or hip (OA), which was not adequately controlled by non-opioid analgesics and/or weak opioids.

METHODS

The study design incorporated a 1-week run-in period when current analgesic medications were optimised, a 28-day treatment period and a 1-week taper-off period. Patients with RA (n = 104) and OA (n = 159) started treatment with TDF 25 microg/h. Patches were replaced every 72 h, with the option to up-titrate until adequate pain control was achieved. Metoclopramide was taken during the first treatment week and as needed thereafter.

RESULTS

203 patients completed the treatment phase, 90 entered the taper-off phase. 25 microg/h was the most frequently used maximum dose (51%). Pain control was increased from 4% to 29% of patients during run-in. The number of patients reaching adequate pain control in the first treatment week was increased to 75%, and increased further to 88% on day 28 and to 80% at endpoint. From baseline (screening) to endpoint, there were significant reductions in pain (p < 0.001) on the Wisconsin Brief Pain Inventory, and significant improvements in quality of life (Short-Form-36: physical p < 0.001; mental health p < 0.05). Eighty per cent of the patients (n = 134) assessed the treatment favourably; nausea and vomiting were the most common adverse events, mainly occurring at treatment initiation. Efficacy of metoclopramide appeared limited. TDF could be initiated in patients pre-treated with non-opioid analgesics or weak opioids and tapered off without major complications.

CONCLUSIONS

TDF significantly improved pain control and quality of life, and was well tolerated in patients with RA or knee/hip OA who continued to experience pain on their current analgesic treatment. Treatment could be discontinued without issues. Nausea and vomiting was usually mild during treatment initiation. Patients' well being could be further accommodated by optimising prophylactic treatment.

Etoricoxib reduced pain and disability and improved quality of life in patients with chronic low back pain: a 3 month, randomized, controlled trial

BACKGROUND

Chronic low back pain (LBP) is a growing health problem. Non-steroidal anti-inflammatory drugs (NSAIDs) are used to treat this condition, but have not demonstrated efficacy beyond 2 weeks, and no studies have shown that NSAIDs produce durable improvements in disability.

METHODS

To evaluate the efficacy and durability of effect of etoricoxib for chronic LBP, a randomized, double blind, placebo-controlled trial was conducted at 46 centres. Three hundred and twenty-five patients with chronic LBP requiring treatment with an NSAID or paracetamol were randomized 1:1:1 to etoricoxib 60 mg (n=109), 90 mg (n=106), or placebo (n=110), daily for 3 months. Pre-specified endpoints over 3 months included LBP intensity scale (visual analog scale 0-100 mm) time-weighted average change from baseline, the Roland-Morris Disability Questionnaire (RMDQ), the LBP bothersomeness scale, patient and investigator global assessments, and measures of quality of life.

RESULTS

Both etoricoxib groups experienced significant reductions in LBP intensity at 4 weeks versus placebo [-15.15 mm and -13.03 mm for 60 and 90 mg, respectively, probability (p)<0.001 for each], which was maintained over 3 months. Treatment resulted in significant improvement from baseline compared to placebo in RMDQ scores (etoricoxib 60 mg, -2.82 and 90 mg, -2.38, p<0.001 for each) over 12 weeks and most other efficacy endpoints. There were no significant differences between treatments in incidence of adverse events (AEs) or discontinuations due to AEs.

CONCLUSION

Etoricoxib provided significant relief of symptoms and disability associated with chronic LBP detected at 1 week, confirmed at 4 weeks, and maintained over 3 months. Reductions in chronic LBP severity corresponded to improvements in physical functioning and quality of life. All treatments were generally well tolerated.

Discovery of a potent, selective and orally active canine COX-2 inhibitor, 2-(3-difluoromethyl-5-phenyl-pyrazol-1-yl)-5-methanesulfonyl-pyridine

Structure-activity relationship (SAR) studies of 2-[3-di(and tri)fluoromethyl-5-arylpyrazol-1-yl]-5-methanesulfonylpyridine derivatives for canine COX enzymes are described. This led to the identification of 12a as a lead candidate for further progression. The in vitro and in vivo activity of 12a for the canine COX-2 enzyme as well as its in vivo efficacy and pharmacokinetic properties in dog are highlighted.

Systemic pharmacologic postoperative pain management in the geriatric orthopaedic patient

Although older adults have surgical procedures more frequently than any other group, they also experience the worst postoperative pain management. Among patients with orthopaedic disorders, this undertreatment of pain impacts postsurgical functional recovery and clinical outcomes. Recently adopted evidence-based pain management guidelines have improved care, but there still is significant room for improvement. We review standards for pain assessment in cognitively intact and impaired older adults, provide detailed guidelines for the pharmacologic treatment of postoperative pain in the orthopaedic geriatric patient, and review the stepwise approach to effective side-effect management in this population.

Nonsteroidal anti-inflammatory drugs in veterinary ophthalmology

Uveitis is a common sequela to many ocular diseases. Primary treatment goals for uveitis should be to halt inflammation, prevent or control complications caused by inflammation, relieve pain, and preserve vision. Systemic and topical NSAIDs are essential components of the pharmaceutic armamentarium currently employed in the management of ocular inflammation by general practitioners and veterinary ophthalmologists worldwide. NSAIDs effectively prevent intraoperative miosis; control postoperative pain and inflammation after intraocular procedures, thus optimizing surgical outcome; control symptoms of allergic conjunctivitis;alleviate pain from various causes of uveitis; and circumvent some of the unwanted side effects that occur with corticosteroid treatment. Systemic NSAID therapy is necessary to treat posterior uveitis, because therapeutic concentrations cannot be attained in the retina and choroid with topical administration alone, and is warranted when diseases, such as diabetes mellitus or systemic infection, preclude the use of systemic corticosteroids. Risk factors have been identified with systemic and topical administration of NSAIDs. In general, ophthalmic NSAIDs may be used safely with other ophthalmic pharmaceutics; however, concurrent use of drugs known to affect the corneal epithelium adversely, such as gentamicin, may lead to increased corneal penetration of the NSAID. The concurrent use of NSAIDs with topical corticosteroids in the face of significant preexisting corneal inflammation has been identified as a risk factor in precipitating corneal erosions and melts in people and should be undertaken with caution[8]. Clinicians should remain vigilant in their screening of ophthalmic and systemic complications secondary to drug therapy and educate owners accordingly. If a sudden increase in patient ocular pain (as manifested by an increase in blepharospasm, photophobia, ocular discharge, or rubbing)is noted, owners should be instructed to contact their veterinarian promptly.

QSAR analysis of cyclooxygenase inhibitor using particle swarm optimization and multiple linear regression

Quantitative structure-activity relationship (QSAR) models of inhibiting action of some diarylimidazole derivatives on cylcooxygenase (COX) enzyme were constructed using modified particle swarm optimization (PSO) method. As a comparison to this method, the genetic algorithm (GA) was also tested. It has been demonstrated that the modified PSO is a useful tool for variable selection comparable to GA and even superior to GA. QSAR models are constructed separately for COX-2 inhibitory activity and selectivity of COX-2 inhibition over COX-1. The spatial descriptors play a key role in the compounds' activity and selectivity to COX-2, especially Jurs descriptors. Polar interactions are the principal binding strength between compounds and COX-2 enzyme. In addition, the aqueous desolvation free energy (FH2O) value of substituent will affect the COX-2 inhibitory activity, while the charge distribution can affect the selectivity to COX-2.

Synthesis and biological evaluation of 2,3-diarylpyrazines and quinoxalines as selective COX-2 inhibitors

Several 2,3-diaryl pyrazines and quinoxalines with 4-sulfamoyl (SO(2)NH(2))/methylsulfonyl (SO(2)Me)-phenyl pharmacophores have been synthesized and evaluated for the cyclooxygenase (COX-1/COX-2) inhibitory activity. Smaller groups such as methoxy, methyl and fluoro when substituted at/around position-4 of the adjacent phenyl ring, have great impact on the selective COX-2 inhibitory activity of the series. Many potential compounds were obtained from a brief structure-activity relationship (SAR) study. Two of these, compounds 11 and 25 exhibited excellent in vivo activity in the established animal model of inflammation. Since compound 25 possessed an amenable sulfonamide group, two of its prodrugs 48 and 49 were also synthesized. Both of them have excellent in vivo potential, and represent a new class of COX-2 inhibitor.

Acute toxic renal failure

Acute renal failure (ARF) is a common problem in intensive care medicine. Even modest degrees of ARF not requiring dialysis treatment increase the risk of death approximately fivefold. Despite the widespread appreciation of the role of nephrotoxic drugs in their contribution to ARF, these drugs continue to have an ongoing aetiological role. Potentially nephrotoxic drugs include non-steroidal anti-inflammatory drugs, radiocontrast agents, antimicrobial and anaesthetic agents. Endogenous compounds such as myoglobin and haemoglobin may furthermore cause toxic nephropathy. Tubular injury initiated by toxins often results from a combination of acute renal vasoconstriction and direct cellular toxicity due to intracellular accumulation of the toxin, or, alternatively, may be mediated immunologically in case of interstitial nephritis. Patients with reduced renal functional reserve, cardiovascular co-morbidity, diabetes mellitus, and advanced age are at increased risk. Awareness of the range of toxins on the one hand and simple measures such as adequate pre-hydration of the patient and drug monitoring on the other hand may be sufficient to avoid drug-induced ARF or minimize its clinical severity in susceptible patients.

Nephrotoxic potential of selective cyclooxygenase-2 inhibitors

OBJECTIVE

To determine the relative nephrotoxic potential of cyclooxygenase (COX)-2 inhibitors.

DATA SOURCES

A MEDLINE search (1996-February 2004) identified clinical trials evaluating the nephrotoxicity of COX-2 inhibitors versus traditional nonsteroidal antiinflammatory drugs (NSAIDs). Key search terms included cyclooxygenase inhibitors, nonsteroidal antiinflammatory agents, nephrotoxicity, and chemically induced.

DATA SYNTHESIS

Three clinical trials determined that COX-2 inhibitors have similar adverse effects on the kidney when compared with nonselective NSAIDs, while 2 studies concluded that COX-2 inhibitors are less nephrotoxic than nonselective NSAIDs. All 5 trials utilized low numbers of subjects, short-term therapy, and surrogate markers of kidney damage.

CONCLUSIONS

COX-2 inhibitors may not offer distinct advantages over nonselective NSAIDs with respect to kidney function. Longer trials in patients with comorbidities are warranted. These agents should be used cautiously or not at all in patients with predisposing conditions.

Polar substitutions in the benzenesulfonamide ring of celecoxib afford a potent 1,5-diarylpyrazole class of COX-2 inhibitors

Several chemical modifications in the N(1)-benzenesulfonamide ring of celecoxib are presented. The series with a hydroxymethyl group adjacent to the sulfonamide was found to be the most potent modification that yielded many compounds selectively active against COX-2 enzyme in vitro.

Treatment of chronic low back pain with etoricoxib, a new cyclo-oxygenase-2 selective inhibitor: improvement in pain and disability—a randomized, placebo-controlled, 3-month trial

We evaluated etoricoxib, a novel COX-2-specific inhibitor, in 319 patients with chronic low back pain (LBP) in this double-blind, placebo-controlled trial. Patients were randomized to a 60 mg dose (n = 103) or 90 mg dose (n = 107) of etoricoxib, or placebo (n = 109), daily for 12 weeks. The primary endpoint was low back pain intensity scale (Visual Analog Scale of 0- to 100-mm) time-weighted average change from baseline over 4 weeks. Other endpoints included evaluation over 3 months of low back pain intensity scale, Roland-Morris Disability Questionnaire (RMDQ), low back pain bothersomeness scale, patient- and investigator-global assessments, Patient Health Survey (MOS SF-12), rescue acetaminophen use, and discontinuation due to lack of efficacy. Etoricoxib provided significant improvement from baseline versus placebo in pain intensity (4 weeks: 12.9 mm and 10.3 mm for 60-mg and 90-mg doses, P <.001 for each; 12 weeks: 10.5 mm and 7.5 mm for 60-mg and 90-mg doses, P =.001 and.018, respectively). Etoricoxib at either dose led to significant improvement in other endpoints, including RMDQ scores, bothersomeness scores and global assessments. Etoricoxib given once daily provided significant relief of symptoms, and disability associated with chronic LBP that was observed 1 week after initiating therapy, was maximal at 4 weeks, and was maintained over 3 months.

Synthesis and structure-activity relationship of a new series of COX-2 selective inhibitors: 1,5-diarylimidazoles

The synthesis and the pharmacological activity of a series of 1,5-diarylimidazoles developed as potent and selective cyclooxygenase-2 (COX-2) inhibitors are described. The new compounds were evaluated both in vitro (COX-1 and COX-2 inhibition in human whole blood) and in vivo (carrageenan-induced paw edema, air-pouch, and hyperalgesia tests). Modification of all the positions of two regioisomeric imidazole cores led to the identification of 4-[4-chloro-5-(3-fluoro-4-methoxyphenyl)imidazol-1-yl]benzenesulfonamide (UR-8880, 51f) as the best candidate, which is now undergoing Phase I clinical trials.

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.

Drug-induced renal failure: update on new medications and unique mechanisms of nephrotoxicity

Medications cause renal failure through a variety of mechanisms. Hemodynamic renal failure may result from drugs that reduce renal prostaglandins and hence renal blood flow and glomerular filtration rate. A relatively new group of drugs with this potential is the cyclooxygenase-2 selective inhibitors. Direct renal tubular toxicity has also been described with a number of new medications with unique effects on the epithelial cells of the kidney. These include the antiviral agents cidofovir, adefovir, and tenofovir as well as the bisphosphonate pamidronate. Additionally, crystal deposition in the kidney may promote the development of renal failure. Several different drugs have been described to induce crystal nephropathy, including the antiparasitic drug sulfadiazine, the antiviral agent acyclovir, and the protease inhibitor indinavir. Finally, an unusual form of renal failure characterized by swollen, vacuolated proximal tubular cells can develop from hyperosmolar substances. Agents recently described to induce an "osmotic nephrosis" include intravenous immunoglobulin and the plasma expander hydroxyethyl starch.

Acute renal failure in patients with cirrhosis: perspectives in the age of MELD

In patients with cirrhosis, acute renal failure is mainly due to prerenal failure (caused by renal hypoperfusion) and tubular necrosis. The main causes of prerenal failure are "true hypovolemia" (induced by hemorrhage or gastrointestinal or renal fluid losses), sepsis, or type 1 hepatorenal syndrome (HRS). The frequency of prerenal failure due to the administration of nonsteroidal anti-inflammatory drugs or intravascular radiocontrast agents is unknown. Prerenal failure is rapidly reversible after restoration of renal blood flow. Treatment is directed to the cause of hypoperfusion, and fluid replacement is used to treat most cases of "non-HRS" prerenal failure. In patients with type 1 HRS with very low short-term survival rate, liver transplantation is the ideal treatment. Systemic vasoconstrictor therapy (with terlipressin, noradrenaline, or midodrine [combined with octreotide]) may improve renal function in patients with type 1 HRS waiting for liver transplantation. MARS (for molecular adsorbent recirculating system) and the transjugular intrahepatic portosystemic shunt may also improve renal function in these patients. In patients with cirrhosis, acute tubular necrosis is mainly due to an ischemic insult to the renal tubules. The most common condition leading to ischemic acute tubular necrosis is severe and sustained prerenal failure. Little is known about the natural course and treatment (i.e., renal replacement therapy) of cirrhosis-associated acute tubular necrosis.

Loop diuretics: from the Na-K-2Cl transporter to clinical use

The diuretic response to loop diuretics in various disease states has consistently been found to be subnormal. One of the key determinants of the degree of diuretic response is the functional integrity of the sodium-potassium-chloride transporter in the loop of Henle. Studies in animal models suggest that expression/activity of the transporter may be affected by factors such as altered natural splicing events of NKCC2 (the gene encoding for the renal transporter), renal prostanoids, vasopressin, and other autacoids. We have reviewed the pharmacokinetics and pharmacodynamics of loop diuretics in health and in edematous disorders for which they are used. On the basis of evidence reviewed in this paper, we propose that altered expression or activity of the sodium-potassium-chloride transporter in the loop of Henle, in conjunction with events occurring in other segments of the nephron, possibly accounts for the altered diuretic response to these agents. Thus the modulators of this altered expression/activity could serve as important therapeutic targets for alternative diuretic regimens in these conditions.

Frequency of use of acetaminophen, nonsteroidal anti-inflammatory drugs, and aspirin in US women

PURPOSE

To determine the frequency of use of the three main classes of over-the-counter analgesics: acetaminophen, non-steroidal anti-inflammatory drugs, and aspirin in two large US female cohorts.

METHODS

We conducted a cross-sectional study of the frequency of analgesic use and the characteristics of users in female participants in the Nurses Health Study I (n = 86,985) and the Nurses Health Study II (n = 93,002) who were between the ages of 33 and 77 years. Information on frequency of current analgesic use was assessed by mailed questionnaire.

RESULTS

All three classes of analgesics were used frequently. For example, acetaminophen was used > or = 1 day/week by more than 20% of women. NSAIDs were used > or = 1 day/week by 42% of women aged 51 years or younger, and aspirin was used > or = 6 days/week by 25% women over age 51 years. The frequency of use of the individual analgesics varied by age (p < 0.001). In addition, women in the highest category of use of any of the analgesics tended to have a higher body mass index, were more likely to have hypertension and diabetes, and were more likely to be current smokers.

CONCLUSIONS

Analgesic use is very common among US women. Physicians should be cognizant of the frequency of use of the various over-the-counter analgesics in their female patient population.

Nephrotic syndrome and interstitial nephritis associated with celecoxib

Nonsteroidal anti-inflammatory drugs (NSAIDs) are well known to cause fluid and electrolyte abnormalities and renal failure. NSAIDs also may cause an acute allergic interstitial nephritis (AIN) and the nephrotic syndrome, characterized by histologic pathology consistent with minimal change disease in patients with previously normal renal function. The nephrotoxic potential of cyclooxygenase 2 (COX-2) inhibitors has not been established because AIN associated with nephrotic syndrome has not been reported secondary to the COX-2 inhibitors. This case report describes the first case of AIN associated with nephrotic syndrome in a patient treated with the selective COX-2 inhibitor, celecoxib.

The Renal Effects of Traditional Nonsteroidal Anti-Inflammatory Agents Versus Cyclooxygenase-2 Inhibitors

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used for the management of acute and chronic pain as well as for rheumatoid arthritis and osteoarthritis. Although gastrointestinal complications are the most common adverse events associated with the use of these drugs, the renal adverse effects such as acute renal failure, electrolyte abnormalities, nephrotic syndrome, interstitial nephritis, and papillary necrosis can be serious. The cyclooxygenase-2 (COX-2)- selective NSAIDs (celecoxib, rofecoxib) have been associated with a reduced frequency of gastrointestinal adverse events, but questions still remain as to their renal safety. Recent information has suggested an increased role for COX-2 as a constitutive renal enzyme, thus implying its importance for normal kidney homeostasis. Clinical studies and published case reports of renal adverse events associated with COX-2 inhibitors suggest that patients with decreased effective circulating blood volume, salt depletion, and renal insufficiency have an increased likelihood of renal-related adverse events. Because many older patients have conditions that place them in one of the “at-risk” categories, this population should be monitored closely for the development of renal adverse events from any NSAIDs, including COX-2-selective agents.

Cyclooxygenase-2 inhibitor-associated acute renal failure: case report with rofecoxib and review of the literature

Cyclooxygenase (COX)-2 inhibitors are widely prescribed for their antiinflammatory and analgesic effects. The potential for COX-2 inhibitors to exert deleterious effects on renal function similar to those of traditional nonsteroidal antiinflammatory drugs is not well defined. Until recently, COX-1 was considered responsible for the synthesis of renal prostaglandins. However, COX-2 is also constitutively expressed in the human kidney Clinical studies have reported a significant decrease in glomerular filtration rate in young and elderly sodium-depleted volunteers given COX-2 inhibitors. We describe the case of a 71-year-old woman who developed acute renal failure after receiving a 50-mg dose of the selective COX-2 inhibitor rofecoxib.

The safety of drugs for OTC use: what evidence is required for an NSAID switch?

In recent years there has been a growing demand for safe and effective over-the-counter (OTC) drugs. The demonstration of the safety of OTC products in actual conditions of use is crucial for their wide distribution, since the circumstances of their use may be different from the prescription-only setting. A group of experts met in Geneva, Switzerland, with the aim of exploring the criteria required to show safety equivalence of OTC medications, with specific reference to low-dose non-steroidal anti-inflammatory drugs (NSAIDs) used for analgesia. It was agreed that an acceptable surrogate marker for safety as the primary endpoint in a study designed to show that a new NSAID was not inferior to a current NSAID would be any adverse event leading the patient to consult a physician. A sample size of 10,000 patients in each arm of a two-arm study would be sufficient to show non-inferiority with acceptable relative risk equal to 1.2 with at least 90% power for an event rate of 5%. An example of a possible pharmacy-based randomized study design to demonstrate safety equivalence of OTC analgesics is given.

Topical nonsteroidal anti-inflammatory drugs for ophthalmic use: a safety review

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used agents that despite chemically heterogeneity, share similar therapeutic properties and adverse effects. Topical ophthalmic NSAIDs are limited to the relatively water soluble phenylacetic and phenylalkanoic acids as well as indole derivatives, which are more suitable for ophthalmic use. Topical ophthalmic NSAIDs are commonly used in the treatment of post-operative inflammation following cataract extraction and various surgical refractive procedures. They are also used in the prevention and treatment of cystoid macular oedema and for the treatment of allergic conjunctivitis. Absorption of topical ophthalmic NSAIDs through the nasal mucosa results in systemic exposure and the occurrence of adverse systemic events, including exacerbation of bronchial asthma. Local irritant effects of topical ophthalmic NSAIDs include conjunctival hyperaemia, burning, stinging and corneal anaesthesia. A more serious complication involves the association of topical ophthalmic NSAIDs with indolent corneal ulceration and full-thickness corneal melts. Analysis of NSAID-associated corneal events implicates the now defunct generic dicolfenac product, diclofenac sodium ophthalmic solution as the agent primarily responsible. However, these events generated a renewed interest in the safety of ophthalmic NSAIDs and a scrutiny of the pharmacology regarding NSAID action in the eye. An elucidation of possible pharmacodynamic explanations of NSAID-induced corneal injury includes the role of epithelial hypoxia, which not only appears to aid in determining the metabolic destination of arachidonate, it may play a key role in orchestrating a novel inflammatory response unrelated to prostanoid formation. The use of NSAIDs under conditions of corneal hypoxia may therefore not only result in a disappointing therapeutic response, it may result in a paradoxical inflammatory exacerbation. Other potential mechanisms include the relationship between NSAIDs and corneal matrix metalloproteinase and direct toxicity due to cytotoxic excipients such as surfactants, solubilisers and preservatives found in topical NSAID ophthalmic preparations. In general, ophthalmic NSAIDs may be used safely with other ophthalmic pharmaceuticals; however, concurrent use of agents known to adversely effect the corneal epithelium, such as gentamicin, may lead to increased corneal penetration of the NSAID. The concurrent use of NSAIDs with topical corticosteorids in the face of significant pre-existing corneal inflammation has been identified as a risk factor in precipitating corneal erosions and melts and should be undertaken with caution. Until clinical evidence dictates otherwise, data supporting theories of potential pharmacodynamic mechanisms of NSAID injury do not alter the favorable benefit-risk ratio of ophthalmic NSAID use when employed in an appropriate and judicious manner.

Cyclo-oxygenase-2 inhibition increases blood pressure in rats

1 It is known that nonselective cyclo-oxygenase (COX) inhibitors have small but significant effects on blood pressure (BP), most notably in hypertensive patients on antihypertensive medication. Whether selective COX-2 inhibitors also interfere with BP regulation is not well understood. Therefore, we aimed to examine the effect of chronic treatment with a selective COX-2 inhibitor (rofecoxib) on systolic blood pressure (sBP) in normotensive Wistar-Kyoto rats (WKY) and on the developmental changes of sBP in young spontaneously hypertensive rats (SHR). In addition, we investigated a possible influence of salt intake on the effects of COX-2 inhibition on BP in these two rat strains. 2 Rofecoxib dose dependently increased sBP and decreased plasma levels of 6-keto prostaglandin (PG)F(1alpha) in WKY rats fed a normal salt diet (0.6% NaCl, wt wt(-1)), without affecting serum thromboxane (TX)B(2) levels. 3 Rofecoxib significantly elevated sBP in both rat strains fed normal salt or high salt diet (8% NaCl, wt wt(-1)), but not in rats on low salt intake (0.02% NaCl, wt wt(-1)). 4 Rofecoxib significantly decreased plasma levels of 6-keto PGF(1alpha) in both rat strains fed normal or high salt diet, but not in rats during low salt intake. 5 Rofecoxib exerted no influence on the changes of body weight nor on water intake. Plasma renin activity (PRA) and renocortical renin mRNA abundance were not changed by rofecoxib, but plasma aldosterone concentration (PAC) was significantly reduced. 6 These results suggest that chronic inhibition of COX-2 causes an increase of blood pressure that depends on prostacyclin synthesis. Furthermore, this increase is independent on genetic predisposition and can be prevented by salt deprivation. Since water intake and body weight gain were not changed by rofecoxib, fluid retention appears not to be a major reason for the development of hypertension. Similarly, an activation of the renin-angiotensin-aldosterone axis appears to be an unlikely candidate mechanism.

Structure toxicity relationships--how useful are they in predicting toxicities of new drugs?

This chapter provides just a few newer examples of structural moieties found in drugs that have been associated with reactive metabolite formation and toxicities. For a discussion of several other structures in drugs that undergo metabolic activation to reactive intermediates, the reader is directed to previous volumes in this series and other chapters in this book, as well as a previous condensed review (Nelson, 1982). Since that review, some new knowledge allows us to better predict that some structural moieties are more likely than others to form drug reactive metabolites that may be involved in causing toxic effects in humans. For example, most aniline-, thiophene-, and nitroaromatic-containing drugs have had a relatively high incidence of adverse effects, and it would be prudent in the drug discovery process to avoid these substructures if possible. However, as illustrated by the case of olanzapine, these structures may be important for potent activity, and could therefore be beneficial in some cases. The glitazones represent a new class of drugs with a unique thiazolidinedione structure. This raises two important points. First, it demonstrates how limited our knowledge base is in regard to structure toxicity relationships when new structures are introduced. Our approaches must be very empirical and are far from quantitative for the reasons outlined in the introduction. Secondly, the glitazones point out the importance of benefit/risk considerations. This was a new structural class of drugs with a unique spectrum of action that is very beneficial in the treatment of a major disease. Despite some suspected risk of toxicity, based on early trials, troglitazone was approved for use with careful monitoring. This author believes that was the right decision, as was the decision to withdraw the drug when the risk became unacceptable, especially with the introduction of safer alternatives. If this were just another NSAID (e.g., bromfenac), there would be little reason for approval. In summary, as I pointed out previously (Nelson, 1982), with our limited knowledge of structure toxicity relationships, we can only make reasonable judgments as to risk assessment of a new drug in humans, and hope that we neither release a dangerous chemical entity nor, as importantly, abort an effective one.

Cyclo-oxygenase-2 inhibitors and the kidney: a case for caution

Cyclo-oxygenase (COX) is one of the key enzymes in the biosynthesis of prostaglandins. Two isoforms of this enzyme COX-1 and COX-2 are known to exist. Among other functions, prostaglandins play an important role in the protection of the gastric mucosa and maintenance of renal function in pathophysiological conditions which would otherwise threaten it. Conventional nonsteroidal anti-inflammatory drugs (NSAIDs) block prostaglandin synthesis, resulting in gastric mucosal injury and renal dysfunction in susceptible individuals. The recent introduction of selective COX-2 inhibitors, celecoxib and rofecoxib, appear to induce less gastrointestinal morbidity. Although conclusive data are still lacking, there is evidence to suggest that COX-2 antagonists may be capable of causing some of the same renal syndromes seen in association with the older, less selective NSAIDs.

Celecoxib-induced acute interstitial nephritis

Data about the nephrotoxicity of selective cyclooxygenase-2 inhibitors are still evolving. Acute interstitial nephritis is a well-described complication of therapy with nonselective nonsteroidal anti-inflammatory drugs. We report a case of biopsy-proven acute interstitial nephritis in a 73-year-old diabetic woman, who had taken celecoxib for more than 1 year before presentation. She presented with clinical findings of subnephrotic proteinuria and acute renal failure that required dialysis. She recovered renal function with cessation of celecoxib therapy after 2 weeks. Other medications were reintroduced safely, without recurrence of renal failure. A kidney biopsy specimen showed acute interstitial nephritis with a prominent eosinophilic infiltrate in the interstitium. This case documents the occurrence of acute interstitial nephritis with celecoxib and emphasizes the need for continued vigilance and care in use of cyclooxygenase-2 inhibitors in high-risk patients.

The different patterns of blood pressure elevation by rofecoxib and nabumetone

Hypertension and knee osteoarthritis (OA) are frequent comorbidities. Nonsteroidal anti-inflammatory drugs (NSAIDs) are often used to relieve pain in such patients. In the last decade selective NSAIDs are used more commonly since they lead to less gastrointestinal complications. As has been shown, the treatment with NSAIDs may cause a mild rise of arterial blood pressure (BP). The influence of selective NSAIDs on BP, particularly in hypertensive patients has still to be investigated. The aim of this study was to determine arterial BP changes in patients suffering from stable arterial hypertension and knee OA and treated with rofecoxib or nabumetone. Two groups of patients with knee OA and stable arterial hypertension received either 25 mg rofecoxib once daily or namebutone 2000 mg once daily during the first week of treatment and 1000 mg for the following 3 weeks. Twenty-four hour arterial BP monitoring was performed prior to initiation of treatment and at the end of a 4-week period. The results were that no changes were found in the mean systolic and diastolic characteristics of BP in the rofecoxib treatment group during day time (delta systolic BP -0.4 mm Hg and delta diastolic BP -0.4 mm Hg), while nocturnal BP increased significantly: delta systolic BP +15.7 mm Hg and delta diastolic BP +8.5 mm Hg. The mean systolic arterial pressure in the nabumeton group raised delta systolic BP 2.9 mm Hg in the daytime and 5 mm Hg during the night-time after the treatment. The mean diastolic arterial pressure also rose delta diastolic 3.2 mm Hg and 4.9 mm Hg at day and night hours respectively. In conclusion rofecoxib treatment did not change arterial BP during day time hours, however, there was a distinct increase in night-time systolic and diastolic BP leading to a disappearance of the physiological diurnal variation. Nabumetone caused a moderate increase of day and night BP, without changes in biological diurnal variation.

Comparison of the morphine-sparing effects of diclofenac sodium and ketorolac tromethamine after major orthopedic surgery

STUDY OBJECTIVES

To compare the efficacy of diclofenac sodium with ketorolac tromethamine in reducing postoperative morphine use after major orthopedic surgery.

DESIGN

Double-blind, randomized, placebo-controlled study.

SETTING

Major teaching institution.

PATIENTS

102 ASA physical status II patients undergoing hip and knee replacement with general anesthesia.

INTERVENTIONS

Before induction of anesthesia, patients were randomly allocated to receive intravenously either diclofenac sodium 75 mg (Group D), ketorolac tromethamine 60 mg (Group K), or placebo (Group P). Patient-controlled analgesia was supplied postoperatively using morphine.

MEASUREMENTS

Visual analog scale (VAS), verbal pain score (VPS), sedation score, frequency of opioid side effects, and morphine consumption were recorded every 4 hours.

MAIN RESULTS

There was a highly significant downward trend for VAS, VPS, and sedation scores over time, p = 0.001. The mean VAS and VPS scores were significantly lower in Groups D and K compared with Group P at time 0, p = 0.009 and 8 hours, p = 0.026. The mean (SD) 24-hour morphine requirements were 36.3 mg (16.9), 47.2 mg (34.9), and 51.6 mg (22.2) for Groups D, K, and P, respectively, p = 0.032. Fewer patients suffered from postoperative nausea and vomiting in the treatment groups (Groups D and K) compared with Group P (9, 8, and 19, respectively), p < 0.05. Fewer patients also suffered from pruritus in Groups D and K compared with Group P (3, 4, and 11, respectively), p < 0.01.

CONCLUSIONS

Preoperative administration of intravenous diclofenac 75 mg or ketorolac 60 mg significantly reduces morphine requirements and associated side effects after major orthopedic surgery.

Renal effects of cyclooxygyenase-2-selective inhibitors

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used. These agents are associated with adverse renal effects caused by the reduction in synthesis of renal prostaglandins through inhibition of cyclooxygenase (COX). Both isoforms of COX, COX-1 and COX-2, are expressed in the kidney in constitutive and inducible forms. It is assumed therefore that the COX-2-selective inhibitors, rofecoxib and celecoxib, would have an effect on renal function similar to that of nonselective NSAIDs. Several studies have evaluated this issue, although they have different study models and some have design flaws that limit their interpretation. Therefore, conclusions should be based on the pattern of observed effects rather than on individual data. These studies suggest that both celecoxib and rofecoxib can cause sodium retention and decrease glomerular filtration rate (GFR) to a similar extent as nonselective NSAIDs in patients at risk for adverse renal effects. Consequently, the same precautions regarding renal risk that are followed for nonselective NSAIDs should be used when selective COX-2 inhibitors are administered.

Pharmacology of cyclooxygenase-2 inhibition in the kidney

Cyclooxygenase (COX) exists as two unique isoforms (that is, COX-1 and COX-2) which are poorly understood with regard to their roles in renal function. The renal effects of conventional non-steroidal anti-inflammatory drugs (NSAIDs) are believed to result from the inhibition of one or both isoforms. Drugs that selectively inhibit COX-2 provide useful pharmacological tools for discerning the effects associated with the inhibition of the individual isoforms, and may help clarify the renal roles of COX-1 and COX-2. This review summarizes the current data on the renal expression of COX isoforms and their potential roles in renal function, and reviews the studies that have attempted to correlate renal functional changes with selective isoform inhibition. Since there are significant differences in the expression of COX isoforms in the kidneys of laboratory animals and humans, this review also examines the correlation of the results of COX inhibition in experimental studies in laboratory animals with clinical data. Because of potential interspecies differences in the roles of COX isoforms in renal function, animal models may have limited predictive value for patients, particularly those with renal risk factors. Accordingly, any uncertainty concerning the safety or therapeutic benefit of COX-2-specific drugs in these patient populations will need to be resolved with clinical investigations.