Ketorolac-induced acute renal failure and hyperkalemia: report of three cases

Spontaneous perirenal urinoma induced by NSAID-associated acute interstitial nephritis

Urinoma, defined as the urine leakage beyond the urinary tract, is commonly induced by blunt trauma or urinary tract obstruction by stone, intra-abdominal malignancy, or retroperitoneal fibrosis. Spontaneous urinoma is rare and parenchymal pathologic change is rarely mentioned when urinoma is found. We present a case of a 28-year-old woman with bilateral flank pain induced by spontaneous urinoma. The lady received chronic analgesics because of migraine. After intravenous ketorolac injection, bilateral perirenal urinoma developed. Renal biopsy showed acute interstitial nephritis associated with nonsteroid anti-inflammatory drug (NSAID). After discontinuing the medication, urinoma subsided, and the patient was discharged with normal serum creatinine. This was the first case of urinoma induced by NSAID-related interstitial nephritis, and pathophysiology and management of spontaneous urinoma are discussed.

Considering renal risk while managing cancer

Renal function is an important consideration in the management of patients with advanced cancer. There is a reciprocal relationship between cancer and the kidney: chronic kidney disease can increase the risk of developing cancer, and patients with cancer often experience renal impairment owing to age, disease-related factors and nephrotoxic treatments. As therapies for cancer continue to improve, patients are living longer with their disease, potentially extending the period over which they are susceptible to long-term complications. Furthermore, secondary symptoms, such as bone metastases or infections, may arise that will require treatment. Certain treatments, including chemotherapy, antibiotics and some bone-targeted agents, are nephrotoxic and may require dose modifications or interruptions to prevent renal injury. Nephrologists should play a key role in the identification and management of renal impairment in patients with cancer. Furthermore, they may be able to provide advice on protecting the kidneys in instances where nephrotoxic agents require dose reductions or interruptions, and when novel therapies or combinations are used. Collaboration between oncologists and nephrologists is important to optimal patient management. This article reviews the relationship between cancer and kidney disease and examines the treatments that may impact kidney function. Considerations for monitoring renal function are also discussed.

Nonsteroidal antiinflammatory drugs, cyclooxygenase-2, and the kidneys

Nonsteroidal antiinflammatory drugs (NSAIDs) are one of the most commonly used classes of medications in the world, which function by inhibiting the cyclooxygenase (COX) enzymes and downregulating the inflammatory pathway. COX enzymes are constitutively expressed in the kidneys and function to maintain a homeostatic environment in terms of maintaining the glomerular filtration rate, blood pressure, sodium, water, and osmotic regulation. When the COX enzymes are inhibited by NSAIDs, a multitude of renal and vascular complications occur. This article aims to enlighten primary care physicians of the complications that arise with NSAIDs from a renal perspective and to present some management strategies.

Dosing of antirheumatic drugs in renal disease and dialysis

Many patients with rheumatic diseases have their management complicated by renal problems. Renal failure modifies the metabolism of many drugs, especially by retention. Questions often arise about the effects of renal failure on the handling of drugs commonly used in rheumatology. For which drugs must we be especially concerned about increased toxicity? Patients on chronic dialysis may also need a variety of drugs for rheumatic disease. How are our drugs dialyzed, and which of these can be safety used and how best to use them?Decisions about dosing of rheumatic drugs are often required for the patients with chronic renal insufficiency or on long-term dialysis, although many drugs have not been formally studied in these settings. Patients with renal insufficiency are excluded from most drug trials. Data for some of these drugs have to be extrapolated based on the information available about the pharmacokinetics of the drug.This review addresses dosing of commonly used drugs in rheumatology in patients with chronic renal insufficiency or failure. It is compiled from a MEDLINE search of papers dealing with renal handling of antirheumatic drugs and suggestions for dose adjustments for these drugs. Drugs reviewed include commonly used disease-modifying antirheumatic drugs (DMARDS), drugs used for treatment of gout, commonly used nonsteroidal antnflammatory drugs (NSAIDS) and the newer COX-2 inhibitors.

The association between nonsteroidal anti-inflammatory drugs and potassium concentrations: A pharmacoepidemiological study in Saudi Arabia

OBJECTIVE

Several nonsteroidal anti-inflammatory drugs (NSAIDs) have been linked to cardiac death. The mechanism that is responsible for this adverse effect appears to be ischemic insult; however, another possible mechanism involves hyperkalemia. The objective of the present study was to determine the feasibility of conducting pharmacoepidemiological studies in Saudi Arabia using refill prescription data to investigate the association between NSAIDs and increased serum potassium concentrations.

METHODS

This retrospective cohort study included patients from an academic medical center in Riyadh, Saudi Arabia. The patients who were recently prescribed NSAIDs were compared to a control group of paracetamol users, with respect to the drugs' effects on serum potassium concentrations. The covariates that affected the potassium concentration or the use of NSAIDs were controlled for in the analysis. The studied outcome was the first serum potassium concentration of more than 5 mEq/L.

RESULTS

A total of 184 patients were prescribed NSAIDs (n = 101) or paracetamol (n = 83) and met the inclusion criteria. Compared to the control group, the patients who received NSAIDs were more likely to be women, were less likely to use angiotensin-converting enzyme inhibitors, and were more likely to have lower baseline serum creatinine concentrations. The other baseline characteristics were similar between the patients in the NSAID group and the patients who received paracetamol. Compared to the patients who were prescribed paracetamol, those who were prescribed NSAIDs did not have an increased risk of hyperkalemia (odds ratio, 1.1, 95% confidence interval, 0.17-6.7, P = 0.95).

CONCLUSION

In the present, small feasibility study, no increase in the risk of hyperkalemia was associated with NSAIDs compared to paracetamol. The present study was exploratory and included only a small number of patients; therefore, this study may not be sufficiently powered to detect small differences between the groups. Future studies with larger sample sizes are needed to investigate the association between NSAIDs and hyperkalemia.

Risk of hyperkalemia associated with selective COX-2 inhibitors

BACKGROUND

Selective cyclooxygenase-2 (COX-2) inhibitors have been linked to cardiac death. The mechanism for this adverse effect appears to be by ischemic insult; however another mechanism could involve hyperkalemia. The objective of this study was to determine the effects of selective COX-2 inhibitors and non-selective nonsteroidal anti-inflammatory drugs (NSAIDs) on serum potassium concentration and the electrocardiogram.

METHODS

A retrospective cohort study was conducted using propensity score matching of patients from an inner-city academic medical center at Indianapolis, Indiana. Two hundred and two patients prescribed selective COX-2 inhibitors were matched to 202 patients prescribed non-selective NSAIDs using propensity scores methods. Outcomes included change in serum potassium concentration from baseline and the risk of an abnormal electrocardiogram.

RESULTS

Compared to patients prescribed non-selective NSAIDs, those prescribed a selective COX-2 inhibitor had a higher risk of serum potassium increase greater than 5 mEq/L (OR, 2.56; 95%CI, 1.03-6.36). However, patients prescribed selective COX-2 inhibitors had no greater risk of electrocardiogram abnormality (OR, 1.16; 95%CI, 0.74-1.82).

CONCLUSIONS

Selective COX-2 inhibitors may have a greater risk of hyperkalemia than non-selective NSAIDs. This study was exploratory with small numbers of patients. Further studies are needed to confirm these results and any association with cardiovascular events.

A double-blind prospective comparison of rofecoxib vs ketorolac in reducing postoperative pain after arthroscopic knee surgery

STUDY OBJECTIVE

The aim of this study was to compare the analgesic efficacy of premedication with rofecoxib vs intravenous (IV) ketorolac in reducing postoperative pain after arthroscopic knee surgery.

STUDY DESIGN

This is a prospective, randomized, double-blinded study.

SETTING

This study was set at a university hospital.

SUBJECTS

The subjects include 54 patients with American Society of Anesthesiologists physical statuses I, II, and III undergoing knee arthroscopy.

INTERVENTIONS

Group 1 received 50 mg oral rofecoxib preoperatively with IV placebo injection, which was administered 20 minutes before the end of the operation. Group 2 received a preoperative placebo and 30 mg IV ketorolac 20 minutes before the end of surgery.

MEASUREMENTS

The primary outcome measure was the proportion of patients reporting pain in the postoperative anesthesia care unit, 6 hours and 24 hours after discharge. Additional end points included the use of 5:325 mg oxycodone-acetaminophen (O/A) tablets, pain scores, patient's satisfaction survey, and comparison of side effects. Data were analyzed using independent samples t tests for continuous variables or chi2 tests for categorical variables. P < .05 was considered significant.

RESULTS

The 2 groups were comparable with regard to patient characteristics, intraoperative medication use, and duration of surgery. There was no difference either in pain scores or O/A use in the postoperative anesthesia care unit. At 24 hours after discharge, significantly more patients in the ketorolac group (91%) reported pain than the rofecoxib group (63%) (P = .02). Sixty-one percent of patients in the ketorolac group used O/A during the first 24 hours vs 38% in the rofecoxib group. The difference, however, was not statistically significant.

CONCLUSION

Preoperative rofecoxib is as effective as ketorolac for the treatment of pain after knee arthroscopy. Higher frequency of pain reporting at 24 hours by patients in ketorolac group is explained by the longer analgesic effect of rofecoxib. Future studies should directly compare gastrointestinal injury of these drugs, as well as cost-effectiveness of rofecoxib vs ketorolac.

Renal expression of COX-2, ANG II, and AT1 receptor in remnant kidney: strong renoprotection by therapy with losartan and a nonsteroidal anti-inflammatory

Chronic renal injury can be mediated by angiotensin II (ANG II) and prostanoids through hemodynamic and inflammatory mechanisms and attenuated by individual suppression of these mediators. In rats with (5/6) renal ablation (Nx), we investigated 1) the intrarenal distribution of COX-2, ANG II, and the AT(1) receptor (AT(1)R); 2) the renoprotective and antiinflammatory effects of an association between the AT(1)R blocker, losartan (Los), and the gastric sparing anti-inflammatory nitroflurbiprofen (NOF). Adult male Munich-Wistar rats underwent Nx or sham operation (S), remaining untreated for 30 days, after which renal structure was examined in 12 Nx rats (Nx(pre)). The remaining rats were followed during an additional 90 days, distributed among 4 treatment groups: Nx(V) (vehicle), Nx(Los) (Los), Nx(NOF) (NOF), and Nx(Los/NOF) (Los/NOF). Nx(pre) rats exhibited marked albuminuria, hypertension, glomerulosclerosis, interstitial expansion, and macrophage infiltration, accompanied by abnormal glomerular, vascular, and interstitial COX-2 expression. ANG II appeared in interstitial cells, in contrast to S, in which ANG II was virtually confined to afferent arterioles. Intrarenal AT(1)R distribution shifted from mostly tubular in S to predominantly interstitial in Nx(pre). All these changes were aggravated at 120 days and attenuated by Los and NOF monotherapies. Los/NOF treatment arrested renal structural injury and ANG II expression and reversed hypertension, albuminuria, and renal inflammation. In conclusion, abnormal expression of COX-2, ANG II, and AT(1)R may be key to development of renal injury in Nx. Concomitant COX-2 inhibition and AT(1)R blockade arrested renal injury and may represent a useful strategy in the treatment of chronic nephropathies.

Cost-effectiveness of different postoperative analgesic treatments

Pain may produce metabolic changes after surgery, which may contribute to further morbidity. A variety of medicines and techniques can be used to successfully treat pain. It is postulated that improved analgesia leads to improved outcomes, although analgesics may also contribute to morbidity. This article reviews the literature evaluating the cost-effectiveness of providing different types of postoperative analgesics and finds that most studies are so poorly conducted that they prevent definitive conclusions being made. The author suggests that further studies be done using analgesics as just one part of a multimodal rehabilitation approach with careful attention to defining outcome, costs and achieving sufficient power to find or exclude meaningful differences.

Ketorolac use in the national football league: prevalence, efficacy, and adverse events

Researchers who surveyed usage patterns, effectiveness, and possible adverse effects of ketorolac tromethamine among National Football League players found some common themes among the 31 teams that responded. Though isolated adverse events were noted, most team healthcare providers felt that ketorolac is effective and safe when the team physician directs its use.

Effect of ketorolac on renal function after donor nephrectomy

OBJECTIVES

To evaluate the safety of ketorolac, a nonsteroidal anti-inflammatory drug, that is being used more frequently for postoperative analgesia, we performed a detailed analysis of healthy patients undergoing open donor nephrectomy.

METHODS

We conducted a retrospective review of 198 consecutive patients who underwent open living donor nephrectomy between January 1998 and July 2000. We compared patients who were and were not given ketorolac. Regression analysis was used to determine whether any significant interactions were present between ketorolac and donor age, sex, weight, estimated surgical blood loss, or operative time in terms of its effect on renal function. Creatinine clearance was calculated by the Gault-Cockcroft equation.

RESULTS

Among the 83 patients given ketorolac, the mean amount received was 200 mg (range 30 to 360, median 210). No differences were found in the preoperative creatinine clearance between patients who did (118 +/- 29 mL/min) or did not (118 +/- 27 mL/min, P = 0.89) receive ketorolac. Patients who received ketorolac had a slightly lower creatinine clearance on the second postoperative day relative to patients who did not receive ketorolac (66% versus 72% of preoperative calculated creatinine clearance, P = 0.05). However, at a minimum of 3 months postoperatively, the creatinine clearance did not differ between the two groups (70% versus 73%, P = 0.92). Among patients who received ketorolac, no significant association was found between the amount received and renal function at any point tested. In the regression analysis, no significant interactions were found between ketorolac and the clinical variables of age, sex, weight, estimated surgical blood loss, or operative time. Moreover, in an analysis of only the patients who received ketorolac, no significant interactions were found between the amount of ketorolac received and the clinical variables of age, sex, weight, estimated surgical blood loss, or operative time.

CONCLUSIONS

Ketorolac use was not associated with any long-term impairment in renal function when used during the first 2 postoperative days in healthy patients undergoing open donor nephrectomy. Moreover, in the range administered, no subset of patients or maximal ketorolac dose was identified at which ketorolac use was not safe.

Outpatient uterine artery embolization for symptomatic uterine fibroids: experience in 49 patients

PURPOSE

To assess the feasibility of performing uterine artery embolization as an outpatient treatment for symptomatic uterine fibroids.

MATERIALS AND METHODS

Forty-nine consecutive patients (mean age, 44.5 years; range, 28-54 years) underwent uterine artery embolization during a 12-month period. Embolization was performed with 350-500 microm polyvinyl alcohol particles (44 of 49) or Gelfoam pledgets (five of 49). At discharge, patients were given instructions regarding the constitutional symptoms to expect after embolization. A specific medication regimen consisting of prochlorperazine, ketorolac, meperidine, and hydrocodone was prescribed for relief of these symptoms. All patients were telephoned within 24 hours of discharge. During long-term follow-up, a questionnaire was administered to all patients to evaluate the periprocedural experience. Three-month clinical follow-up was available in 26 patients and 6-month imaging follow-up was available in 16 patients.

RESULTS

Fourteen patients presented with menorrhagia, six had bulk-related symptoms (abdominal distension, stress incontinence, pelvic pain), and 29 had both. Technical success for bilateral embolization was 98%. Forty-seven of 49 patients were discharged to home 6-8 hours after the procedure; two patients required overnight observation in an ambulatory unit (one because of postprocedure hypertension and one because of a late procedure completion time). At the first follow-up phone call, reported symptoms included pelvic pain/cramping in 83.7% (41 of 49), fatigue in 75.5% (37 of 49), nausea/vomiting in 46.9% (23 of 49), and a nonpurulent vaginal discharge in 18.4% (nine of 49). These symptoms were satisfactorily controlled with discharge medications in 48 of 49 patients. No patients returned to the hospital or visited an emergency room during the first 48 hours after discharge. Forty-six of 49 patients were satisfied with the decision for home discharge. The average uterine volume reduction in 16 patients with 6-month imaging follow-up was 47.5%; 88.5%, of patients (23 of 26) with 3-month clinical follow-up reported improvement or elimination of symptoms.

CONCLUSION

With defined telephone follow-up, staff availability, and a protocol designed to alleviate the postprocedure constitutional symptoms, uterine artery embolization is both safe and effective when performed as an outpatient procedure.

Acetaminophen as an adjunct to morphine by patient-controlled analgesia in the management of acute postoperative pain

Opioids play a fundamental role in the management of postoperative pain, but their use is associated with a number of side effects, including nausea and vomiting, sedation, and respiratory depression. Co-administration of a nonopioid has been proposed as a method of reducing opioid intake and minimizing side effects. Sixty-one ASA physical status I and II patients were enrolled in a double-blind, randomized, placebo-controlled, parallel study to investigate the effect of a combination of acetaminophen and morphine after open reduction and internal fixation of acute limb fractures. Patients were randomized to receive either oral acetaminophen (1 g every 4 h) or placebo as an adjuvant to morphine by patient-controlled analgesia (PCA) postoperatively. They were assessed daily for 72 h or until the PCA was discontinued according to standardized guidelines. The outcome variables collected were pain scores (11-point scale), amount of morphine self-administered, duration of PCA use, compliance with study design, incidence of nausea and sedation, and overall patient satisfaction. The acetaminophen group had lower pain scores on Day 1 (2.1 vs 3.3; P = 0.03) and a shorter average duration of PCA use (35.8 vs 45.5 h; P = 0.03). Overall patient satisfaction was also significantly greater in the acetaminophen group (8.7 vs 7.9; P = 0.04). These data suggest that acetaminophen is a useful adjunct to morphine PCA.

IMPLICATIONS

This study assesses the benefit of combining two analgesics for the treatment of postoperative pain. Such a combination improves the quality of pain relief and patient satisfaction.

Clinical implications of ketorolac for postoperative analgesia

Ketorolac is the only nonsteroidal anti-inflammatory drug (NSAID) in widespread clinical use that is available in an injectable form. Though similar to aspirin and ibuprofen, it is much more potent. In fact, it is potent enough to be useful for postsurgical pain either alone or in combination with other pain relief strategies. For many types of pain, ketorolac is comparable in potency with opioids though the mechanism by which it relieves pain is significantly different. Ketorolac has a much longer duration than morphine or meperidine but has a slower onset. Though we sometimes perceive NSAIDs as almost harmless, ketorolac is a potent drug and, like other potent drugs, has the potential to produce potent adverse effects including organ disfunction and allergic reaction. Risk factors for these adverse effects are well understood, allowing the clinician to plan the ketorolac use safely. Well planned patient selection and ketorolac administration can improve patient care by reducing opioid side effects and improving analgesia while speeding patient recovery and PACU discharge times.

Ketorolac. A reappraisal of its pharmacodynamic and pharmacokinetic properties and therapeutic use in pain management

Ketorolac is a nonsteroidal anti-inflammatory drug (NSAID) with strong analgesic activity. The analgesic efficacy of ketorolac has been extensively evaluated in the postoperative setting, in both hospital inpatients and outpatients, and in patients with various other acute pain states. After major abdominal, orthopaedic or gynaecological surgery or ambulatory laparoscopic or gynaecological procedures, ketorolac provides relief from mild to severe pain in the majority of patients and has similar analgesic efficacy to that of standard dosages of morphine and pethidine (meperidine) as well as less frequently used opioids and other NSAIDs. The analgesic effect of ketorolac may be slightly delayed but often persists for longer than that of opioids. Combined therapy with ketorolac and an opioid results in a 25 to 50% reduction in opioid requirements, and in some patients this is accompanied by a concomitant decrease in opioid-induced adverse events, more rapid return to normal gastrointestinal function and shorter stay in hospital. In children undergoing myringotomy, hernia repair, tonsillectomy, or other surgery associated with mild to moderate pain, ketorolac provides comparable analgesia to morphine, pethidine or paracetamol (acetaminophen). In the emergency department, ketorolac attenuates moderate to severe pain in patients with renal colic, migraine headache, musculoskeletal pain or sickle cell crisis and is usually as effective as frequently used opioids, such as morphine and pethidine, and other NSAIDs and analgesics. Subcutaneous administration of ketorolac reduces pain in patients with cancer and seems particularly beneficial in pain resulting from bone metastases. The acquisition cost of ketorolac is greater than that of morphine or pethidine; however, in a small number of studies, the higher cost of ketorolac was offset when treatment with ketorolac resulted in a reduced hospital stay compared with alternative opioid therapy. The tolerability profile of ketorolac parallels that of other NSAIDs; most clinically important adverse events affect the gastrointestinal tract and/or renal or haematological function. The incidence of serious or fatal adverse events reported with ketorolac has decreased since revision of dosage guidelines. Results from a large retrospective postmarketing surveillance study in more than 20,000 patients demonstrated that the overall risk of gastrointestinal or operative site bleeding related to parenteral ketorolac therapy was only slightly higher than with opioids. However, the risk increased markedly when high dosages were used for more than 5 days, especially in the elderly. Acute renal failure may occur after treatment with ketorolac but is usually reversible on drug discontinuation. In common with other NSAIDs, ketorolac has also been implicated in allergic or hypersensitivity reactions. In summary, ketorolac is a strong analgesic with a tolerability profile which resembles that of other NSAIDs. When used in accordance with current dosage guidelines, this drug provides a useful alternative, or adjuvant, to opioids in patients with moderate to severe pain.

Drug-induced nephrotoxicity: the crucial role of risk factors

Although the exact incidence of drug-induced nephrotoxicity is not known, it is important for clinicians to be aware of the risks in certain patients and to know which drugs are the most commonly implicated. The latter include radiocontrast agents, aminoglycosides, nonsteroidal anti-inflammatory drugs, and angiotensin-converting enzyme inhibitors. Other medications also have nephrotoxic potential when they are prescribed in specific patient populations. Renal injury may be transient and mild in many cases, but recognition of the patient at high risk and application of preventive measures are essential to avoid a severe and protracted course.