Investigating the TNP-OVA and direct popliteal lymph node assays for the detection of immunostimulation by drugs associated with anaphylaxis in humans

Using current animal models, it is not possible to identify low-molecular-weight compounds (LMWCs) that are likely to be associated with anaphylaxis. It is generally accepted that the ultimate effector mechanism involves drug-induced IgE antibody. The objective of the present study was to determine if diclofenac, zomepirac and glafenine, which are associated with anaphylaxis in humans, have immunostimulating potential in the murine TNP-OVA (trinitrophenyl-ovalbumin) popliteal lymph node assay (PLNA), and more specifically to determine if the immunostimulation caused by these LMWCs results in IgE antibody production. These LMWCs were chosen because both zomepirac and glafenine were removed from the market due to high association with anaphylaxis, and diclofenac, which remains on the market, is frequently associated with anaphylaxis. In addition to conducting a TNP-OVA PLNA, the immunostimulating potential of these compounds was examined in the direct PLNA. When co-administered with TNP-OVA, all three LMWCs caused dose-dependent (0.25, 0.50, 1.00 and 1.25 mg) increases in popliteal lymph node (PLN) weight and cellularity that were observed beginning with the 0.25-mg dose. In addition, beginning with the 0.25-mg dose, all three compounds caused dose-dependent increases in TNP-OVA specific IgM and IgG(1) antibody-forming cells (AFCs). Diclofenac induced an isotype switch and caused a dose-dependent increase in the number of IgE AFCs with no detectable IgG(2a) AFCs and minimal high-dose-only IgG(2b) AFCs. Zomepirac induced IgE, IgG(2a) and IgG(2b) AFCs following the injection of 0.50 mg only, and glafenine induced IgE, IgG(2a) and IgG(2b) AFCs following the injection of 0.50-1.00 mg. In the direct PLNA, diclofenac caused dose-dependent increases in PLN weight and cellularity that were observed beginning with dose of 0.50 mg, whereas zomepirac failed to increase any PLN parameter and glafenine only increased the PLN weight. These results suggest that diclofenac, zomepirac and glafenine are immunostimulating LMWCs in the TNP-OVA PLNA with the potential to induce IgE antibody against a co-administered hapten-conjugate. Furthermore, these results suggest that the TNP-OVA PLNA offered significant advantages over the direct PLNA. Although it is not realistic to suggest that a single assay, based on a low number of test compounds, can identify all LMWCs with the potential to cause anaphylaxis in humans, these observations do demonstrate the potential utility of the PLNAs in examining LMWC-induced immunomodulation and support further development and investigation of the assays.     

A population based case-cohort study of drug-induced anaphylaxis.

1. In order to determine the risk of anaphylaxis as an adverse reaction to drugs, a case-cohort study was performed. Cases consisted of all admissions in 1987 and 1988 to all Dutch hospitals with anaphylaxis as the principal diagnosis, and a random sample of admissions with related symptoms. Hospital discharge summaries were classified according to probability to anaphylaxis by a blinded Audit Committee. Of admissions classified as probable or possible anaphylaxis, the causative agent was assessed. The reference cohort consisted of all persons in the catchment area of a sample of pharmacies in The Netherlands, in the period between January 1, 1987 and December 31, 1988. 2. Out of 934 admissions, discharge summaries on 811 admissions were received, of which 727 contained enough clinical details. Out of 727, 391 were classified as probable or possible anaphylaxis. In 336 of these 391, anaphylaxis was reason for admission. This group consisted of 158 men and 178 women. Drug-induced anaphylaxis occurred in 107 patients. 3. Drug-induced anaphylaxis was most frequently caused by penicillins, analgesics and non-steroidal antiinflammatory drugs (NSAID) with the highest point estimate of the risk relative to all other drugs of 10.7, 6.9 and 3.7 respectively. 4. In the cases of probable anaphylaxis, the risk of anaphylaxis to glafenine relative to all other drugs was 167.7 in 1987 (95%-CI: 63.0-446.4) and 128.6 in 1988 (95%-CI: 50.4-328.5), to amoxycillin 15.2 in 1987 (95%-CI: 5.0-46.0) and 4.4 in 1988 (95%-CI: 1.03-18.9) and to diclofenac 6.1 in 1988 (95%-CI: 1.4-26.1).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of suspending agents on the characteristics of some anti-inflammatory suspensions

The effect of suspending agents on the physical stability and in vitro availability of mefenamic acid, flufenamic acid, glafenine, ibuprofen and azapropazone suspensions was studied. The ulcerogenic effect of these formulated suspensions on the stomach of rats was also investigated. The results revealed that 2% veegum and 2% sorbitol gave the best formulated suspension for glafenine as compared to other formulations. On the other hand, 2% veegum, 2% sobitol and 1% avicel was found to improve the physical stability of mefenamic acid and flufenamic acid suspensions. Also, the combination of 1% veegum, 1% sorbitol and 1% algin produced excellent suspension for ibuprofen and azapropazone as compared to other combinations. The results of in vitro release data proved an optimal availability of the above mentioned formulations. In addition, significant reduction in the gastric erosions in stomach of rats was observed in all mentioned suspensions except glafenine suspension.     

127例药物不良反应分析

目的:分析引起不良反应的药物临床表现及防治。方法:回顾性分析临床用药发生不良反应的情况。结果:127例不良反应中,心血管药物77例,占60.63％;其它为内分泌、激素药物22例,占17.32％;抗生素11例,占8.66％;抗癌药3例,占2.36%;其它14例,占11.02％。重症不良反应48例,占37.79％;死亡6例,占4.72％.结论:心血管药物可能引致较严重的不良反应。     

Tiapride versus glafenine: a double-blind comparative study in the management of acute rheumatic pain

Summary

A double-blind study was carried out in 42 patients suffering from acute rheumatic pain to compare the analgesic effectiveness and tolerance of tiapride with that of glafenine, a widely used analgesic in Europe. Patients were allocated at random to receive either 100?mg tiapride or 200?mg glafenine 3-times daily over a period of 14 days. Pain intensity was rated daily by the patients using a visual analogue scale and an overall assessment of response to treatment was made by both patients and physician at the end of the study. The results showed that. whilst both treatments resulted in a marked reduction in mean pain scores, pain disappeared completely in 16 (76%) of the 21 patients treated with tiapride compared with 9 (43%) of the 21 receiving glafenine. There was also a signqicant difference in favour of tiapride in the physician's overall assessment of response which was considered as excellent in 71% of the patients on tiapride compared with 31% receiving glafenine. Both treatments were well tolerated and few side-effects were reported. Drowsiness occurred in 6 patients on tiapride but this was only mild in 5 and moderate in the other patient.     

Spectrophotometric determination of two N-(4-quinolyl) anthranilic acid derivative (glafenine and floctafenine)

Spectrophotometric methods were developed for the determination of glafenine and floctafenine. The first method depends upon the determination of glafenine in raw material and tablets as well as in the presence of its main degradation product glafenic acid (up to 40%). Differential first derivative spectral response at 245 nm in 0.1 N hydrochloric acid, where the corresponding degradation product exhibits no contribution in 0.1 N sodium hydroxide. The method allows the determination of 2.5-30 microg ml(-1). The second method depends upon the reaction of floctafenine with 2,3-dichloro 5,6-dicyano-p-benzoquinone (DDQ) in acetonitrile to give highly colored complex that could be measured quantitatively at (about) lambda(max) 538 nm. The method permits the determination of 40-180 microg ml(-1) or by measuring the first derivative spectral response of the color at 610 nm. The method permits the determination of floctafenine in presence of thiocolchicoside. The methods mentioned both simplicity and sensitivity, having excellent precision and accuracy (100.31 +/- 0.63, 100.78 +/- 0.77 and 99.90 +/- 0.56 for glafenine and floctafenine, respectively). The results were of comparable accuracy and reproducibility with the reported methods.     

Adverse drug reactions leading to hospital admission.

This article describes the implementation of a simple method of drug surveillance set up at a hospital emergency ward. From a total of 48,678 patients admitted, the medical records of those presenting with one or more of a pre-established list of admission diagnoses (n = 7728; 15.8%) were checked. Of these 554 (1.1%) were diagnosed as experiencing an adverse drug reaction. When the medical record suggested an adverse drug reaction, drugs taken before admission were ascertained by interviewing the patients with a structured questionnaire. After excluding upper gastrointestinal bleeding (226 cases) and certain bone marrow blood dyscrasias (42 cases), 286 patients with drug-induced events leading to hospital admission were identified in 2 years. Fatal adverse drug reactions, previously undescribed reactions, and some specific examples, such as digoxin-amiodarone interaction, drug-induced pancreatitis, nicardipine-induced AV block, severe skin reactions, and NSAID-induced bronchospasm, are described. Basically, this method consists of assembling series of cases systematically, and is therefore devoid of selective bias. In addition, it allows a more in-depth clinical and anamnesic study of specific diseases, as compared with voluntary reporting.     

Fluoroquinolone-associated anaphylaxis in spontaneous adverse drug reaction reports in Germany: differences in reporting rates between individual fluoroquinolones and occurrence after first-ever use.

BACKGROUND: The frequency of fluoroquinolone-associated anaphylaxis has been estimated to be 1.8-23 per 10 million days of treatment based on spontaneous reports. It is unknown whether there are differences between the reporting rates of anaphylaxis with individual fluoroquinolones. According to pathophysiology, anaphylaxis may be immune mediated (anaphylactic) or not (anaphylactoid). The latter may occur after first-ever intake since no sensitisation phase is necessary. OBJECTIVE: To analyse spontaneous reports of fluoroquinolone-associated anaphylaxis contained in the spontaneous adverse drug reaction database of the Federal Institute for Drugs and Medical Devices in Germany with regard to differences in reporting rates between various fluoroquinolones, the previous intake and the time to onset of the reaction. METHODS: All fluoroquinolone-associated cases of anaphylaxis, anaphylactic shock, and anaphylactic/anaphylactoid reaction spontaneously reported to the Federal Institute for Drugs and Medical Devices between 1 January 1993 and 31 December 2004 were identified and assessed with regard to the correctness of the diagnosis of anaphylaxis, the causal relationship with the drug, the previous intake of fluoroquinolones and the time to onset of the reaction. RESULTS: In 166 of 204 cases identified, the diagnosis of anaphylaxis and a causal relationship with the drug were considered at least possible. Moxifloxacin, levofloxacin, ciprofloxacin and ofloxacin accounted for 90 (54%), 25 (15%), 21 (13%) and 16 (10%) of the 166 cases, respectively. The corresponding reporting rates per 1 million defined daily doses based on crude estimates of exposure were 3.3, 0.6, 0.2 and 0.2 for moxifloxacin, levofloxacin, ciprofloxacin and ofloxacin, respectively. The occurrence of anaphylaxis after the first dose or within the first three days was reported in 71 of 166 (43%) cases, but no information on prior exposure with this or any other fluoroquinolone was provided with these reports. In 21 of 166 (13%) cases, the reaction occurred within the first 3 days and it was stated that the particular fluoroquinolone had never been taken before. CONCLUSIONS: Anaphylaxis appears to be associated with the fluoroquinolone class of antibacterials. Observed differences in reporting rates should be further investigated. Fluoroquinolone-associated anaphylaxis may occur after first-ever intake of the agent.     

Detection and incidence of drug-induced agranulocytosis in hospital: a prospective analysis from laboratory signals

AIMS: Our objectives were to assess the detection and incidence of drug-induced agranulocytosis in two university hospitals using hematology laboratory data. METHODS: A prospective study was undertaken at Toulouse University Hospital (France) and Navarra University Hospital (Spain) for 1 year (from 1 May 2004 to 30 April 2005). Using a computerized process and hematology laboratory data, all neutrophil counts with a value less than 500/mm(3) were registered, allowing identification of inpatients suffering from agranulocytosis during the period of the study. Medical records of all selected patients were then consulted. Cytostatic drugs were excluded from this study. RESULTS: During the period of the study, 225,659 neutrophil counts were performed in both hospitals, of which 2,835 (1.26%) had a neutrophil count less than 500/mm(3), corresponding to 739 patients. Seventeen patients were excluded because of lack of data, and 20 cases of infants younger than 3 months were excluded. Among the remaining patients (n = 702), 23 cases of drug-induced agranulocytosis (excluding cytostatic drugs) were suspected. All cases were classified as "serious" since they led to death in 2 cases, hospitalization or prolongation of hospitalization in 19 cases and threatening of vital prognosis in 2 cases. Withdrawal of suspected drugs was done in all cases with regression of neutropenia in 21 cases. According to hospitalization data, the annual incidence of drug-induced agranulocytosis was 1.62 (1.0-2.6) per 10,000 inpatients in Toulouse University hospital (based on 534 cases) and 3.24 (0.9-8.3) per 10,000 inpatients in Navarra University Hospital (based on 168 cases). The involved drugs were mainly antibacterial (30.4%), immunosuppressive (17.4%), antithyroid (13.0%), antiplatelet (8.7%) and nonsteroidal anti-inflammatory (8.7%) ones. Only seven cases from Toulouse University Hospital were spontaneously reported by physicians during the same period. Thus, the underreporting coefficient (U) was 2.71 (63.2%) in France. CONCLUSION: Our survey allowed us to identify the suspected drug-induced agranulocytosis through a prospective study in a large sample of inpatients using only laboratory data analysis. We also note an important underreporting rate of this serious adverse drug reaction (ADR) to the official French pharmacovigilance system. Laboratory data analysis could be used for identifying serious ADRs.     

Tiapride versus glafenine: a double-blind comparative study in the management of acute rheumatic pain

A double-blind study was carried out in 42 patients suffering from acute rheumatic pain to compare the analgesic effectiveness and tolerance of tiapride with that of glafenine, a widely used analgesic in Europe. Patients were allocated at random to receive either 100 mg tiapride or 200 mg glafenine 3-times daily over a period of 14 days. Pain intensity was rated daily by the patients using a visual analogue scale and an overall assessment of response to treatment was made by both patients and physician at the end of the study. The results showed that, whilst both treatments resulted in a marked reduction in mean pain scores, pain disappeared completely in 16 (76%) of the 21 patients treated with tiapride compared with 9 (43%) of the 21 receiving glafenine. There was also a significant difference in favour of tiapride in the physician's overall assessment of response which was considered as excellent in 71% of the patients on tiapride compared with 31% receiving glafenine. Both treatments were well tolerated and few side-effects were reported. Drowsiness occurred in 6 patients on tiapride but this was only mild in 5 and moderate in the other patient.     

Comparison of the biological effects in rat of high doses of two 4-amino-7-chloroquinoline derivatives

When given orally in elevated but nonlethal doses (150 to 450 mg/kg, on 2 consecutive days), glafenine induces in rats (body weight 100 g) a transient nephritis with an increase in blood urea, hypertrophy of adrenals, and some changes in the serum proteinogram. These effects do not appear to be due to the 4-amino-7-chloroquinoline structure from which glafenine is derived, as they are not observed with the structural analogue chloroquine given at equimolar doses under the same conditions. Further, they do not appear to be due to glycerol, the by-product of metabolic glafenine hydrolysis. The responsible molecule appears to be either glafenine itself or its acid metabolite 4-(0-carboxyphenylamino) 7-chloroquinoline.     

Population-based drug-related anaphylaxis in children and adolescents captured by South Carolina Emergency Room Hospital Discharge Database (SCERHDD) (2000-2002)

PURPOSE: Anaphylaxis is a life-threatening condition; drug-related anaphylaxis represents approximately 10% of all cases. We assessed the utility of a statewide emergency department (ED) database for identifying drug-related anaphylaxis in children by developing and validating an algorithm composed of ICD-9-CM codes. METHODS: There were 1 314,760 visits to South Carolina (SC) emergency departments (EDs) for patients <19 years in 2000-2002. We used ICD-9-CM disease or external cause of injury codes (E-codes) that suggested drug-related anaphylaxis or a severe drug-related allergic reaction. We found 50 cases classifiable as probable or possible drug-related anaphylaxis and 13 as drug-related allergic reactions. We used clinical evaluation by two pediatricians as the 'alloyed gold standard'1 for estimating sensitivity, specificity, and positive predictive value (PPV) of our algorithm. RESULTS: ED-treated drug-related anaphylaxis in the SC pediatric population was 1.56/100,000 person-years based on the algorithm and 0.50/100,000 person-years based on clinical evaluation. Assuming the disease codes we used identified all potential anaphylaxis cases in the database, the sensitivity was 1.00 (95%CI: 0.79, 1.00), specificity was 0.28 (95%CI: 0.16, 0.43), and the PPV was 0.32 (0.20, 0.47) for the algorithm. Sensitivity analyses improved the measurement properties of the algorithm. CONCLUSIONS: E-codes were invaluable for developing an anaphylaxis algorithm although the frequently used code of E947.9 was often incorrectly applied. We believe that our algorithm may have over-ascertained drug-related anaphylaxis patients seen in an ED, but the clinical evaluation may have under-represented this diagnosis due to limited information on the offending agent in the abstracted ED records. Post-marketing drug surveillance using ED records may be viable if clinicians were to document drug-related anaphylaxis in the charts so that billing codes could be assigned properly.     

Hepatitis bij gebruik van glafenine

Five case-histories have been reported to the Netherlands Centre for Monitoring of Adverse Reactions to Drugs concerning patients with hepatitis, attributed to the use of glafenine (including two previously published cases). In three patients the reaction occurred at more than one occasion. Practitioners are earnestly requested to report analogous cases.

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Mededelingen van het Bureau Bijwerkingen Geneesmiddelen (Staatstoezicht op de Volksgezondheid, Leidschendam) zijn gebaseerd op, door artsen gemelde, vermoede bijwerkingen van geneesmiddelen.     

牛奶大分子蛋白的水解及其抗原性变化

目的 :将婴儿乳粉以不同的食品级蛋白酶水解 ,降低牛奶的分子量 ,考察牛奶酶水解产物过敏原性的变化。方法 :采用胃蛋白酶、胰蛋白酶和自制胰酶制品对婴儿奶粉进行酶解 ,以快速蛋白质液相色谱测得酶解产物分子量分布和所占比例。通过实验动物主动、被动皮肤反应和口服致敏肠腔通透性变化观察不同酶水解后牛奶的过敏原性变化。结果 :快速蛋白质液相色谱结果表明蛋白酶水解牛奶后 ,牛奶蛋白分子量明显降低 ,尤以自制胰酶对乳粉的水解程度最高 (分子量 <10 0 0占 92 % ;10 0 0～10 0 0 0占 8% )。胃蛋白酶、胰蛋白酶和胰酶水解产物可以显著抑制由牛奶蛋白引起的小鼠耳速发型主动皮肤过敏 ,抑制率分别为 5 1%、83%和 86 %。小鼠同种及异种被动皮肤过敏反应实验中 ,与未水解奶粉组比较 ,同种皮肤过敏反应三种酶解产物炎性渗出降低率分别为 2 9%、70 %和 82 % ,异种皮肤过敏反应的降低率分别为 34%、70 %和 82 %。口服致敏小鼠肠腔通透性及分泌功能测定结果显示 ,胰酶水解产物致敏小鼠的肠腔伊文思蓝渗出率比未水解前降低了 2 7%。结论 :酶水解后牛奶大分子蛋白物质降解 ,其过敏原性有不同程度的降低 ,尤以胰酶水解产物变化最为显著。     

Drug-induced anaphylaxis: a decade review of reporting to the Portuguese Pharmacovigilance Authority

Purpose

Anaphylaxis is a potentially fatal systemic adverse drug reaction (ADR). It is an unpredictable and mostly dose-independent event that occurs suddenly following exposure to the causative drug. Our objective was to characterize a case series of anaphylactic reactions reported to the Portuguese Pharmacovigilance authority during the past decade. Patients’ demographic data and implicated drugs were analyzed as well as the severity of the ADR and time trends.

Methods

This study was a retrospective analysis of episodes of anaphylaxis, defined according to the Second Symposium on the Definition and Management of Anaphylaxis Criteria, reported to the Portuguese Pharmacovigilance System between 1 January 2000 and 1 November 2010

Results

Amongst the 16,157 ADR reported to the Portuguese Pharmacovigilance System during the 10-year study period, we found 918 (6 %) cases of anaphylaxis that met the proposed criteria. The age of the patients varied from 7 days to 91 years, with 87 cases (9 %) of anaphylaxis involving patients under 18 years of age. There was an overall female predominance (67 %), but the majority of pediatric patients were male (56 %). There was a trend toward increased reporting as the decade progressed, and 31 % (284) of all anaphylaxis cases were reported during the last 2 years of the study period. Of the anaphylaxis episodes reported, 19 % led to hospitalization and 24 (3 %) had a fatal outcome. Antibiotics were responsible for most cases (17 %) followed by nonsteroidal anti-inflammatory drugs/acetaminophen (13 %), antineoplastic/cytotoxic drugs and immune-modulators. Vaccines and radiographic contrast media were also important contributors to an anaphylactic event.

Conclusions

In this series of drug-related anaphylaxis, we found that most of the reported episodes were associated with widely used drugs, such as antibiotics and analgesics. Anaphylaxis can occur at any age. The female gender was more highly represented, with the exception of pediatric patients.     

Sertindole causes distinct electrocardiographic T-wave morphology changes

Sertindole's propensity to prolong the QT interval relates to blockade of the KCNH2 (HERG) encoded Ikr potassium channel, but there has been limited detailed data on T-wave morphology changes. Digital 12-lead ECG was recorded at baseline and at steady-state in 37 patients switched to sertindole. ECG was analyzed for quantitative T-wave morphology changes and Fridericia-corrected QT duration (QTcF). Prominent T-wave morphology changes occurred during sertindole treatment and in some cases without concomitant prolongation of the QTcF interval. Four patients developed notched T-waves during sertindole treatment. Mean QTc prolongation was 19 ms. The mean effect size was higher for T-wave morphology combination score (MCS) (ES = 1.92; 95% CI: 1.35–2.49) compared to the mean effect size for QTcF (ES = 0.88; 95% CI: 0.52–1.24). The use of T-wave morphology analysis may become clinically relevant, particularly if shown to be associated with drug-induced arrhythmia risk.     

Comparative analgesic efficacy and tolerability of ketorolac tromethamine and glafenine in patients with post-operative pain

Summary

In a randomized, single-dose, double-blind, parallel comparative trial of analgesic efficacy, 96 adult patients received either 10?mg ketorolac tromethamine or 400?mg glafenine orally the morning after surgery if they requested pain relief medication. Each patient provided a baseline pain assessment and then received the assigned medication. Patients assessed pain intensity and pain relief and reported any adverse events in interviews held 30 minutes after drug administration and then hourly for 6 hours. The demographic characteristics, baseline pain intensity, and surgical categories of the 47 patients who received ketorolac tromethamine and the 49 who received glafenine were similar. Both drugs provided prompt, sustained pain relief throughout the 6-hour observation period, and there were no statistically significant differences between the two groups in any of the efficacy measures analyzed. The global assessment recorded by patients suggested a slight clinical advantage for ketorolac tromethamine (32.6% of ‘excellent’ responses) as compared to glafenine (12.5% ‘excellent’). The differences in overall response were statistically significant (p = 0.017). Fourteen (30%) patients who received ketorolac tromethamine and 17 (35%) who received glafenine reported adverse experiences that began or seemed to worsen after administration of the study drugs. The most prominent were drowsiness and sleeping, both of which are common in post-surgical patients.     

Evaluation of mast cell activation (tryptase) in two patients suffering from drug-induced hypotensoid reactions

Tryptase is predominantly found in mast cells, where it resides in secretory granules, and is released with other mediators during mast cell degranulation. By using a newly developed commercial assay for measurements of tryptase levels we have investigated two cases of suspected drug-induced anaphylaxis. Each patient had a similar clinical presentation, consisting of hypotension and cyanosis after administration of thiopentone and suxamethonium. One of the patients showed a highly elevated serum level of tryptase reaching 26 micrograms/l 30 min after the initial reaction. In addition, slightly elevated levels of specific IgE antibodies to thiopentone were detected. The other patient with similar symptoms showed no increase in the level of tryptase, nor any specific IgE to thiopentone or suxamethonium. These data indicate the patient I suffered from true anaphylaxis, whereas the reaction of patient II occurred by a different mechanism.     

Clofibrate disposition in renal failure and acute and chronic liver disease

Summary The disposition of clofibrate over 96 hours was observed following single oral dose in six patients with acute viral hepatitis, six patients with liver cirrhosis, seven patients with renal insufficiency, and six control subjects. No parameter of the disposition of CPIB (active form of clofibrate) was significantly altered in acute hepatitis. In liver cirrhosis, the mean plasma half-life was unchanged compared to controls (20.9 vs. 17.5 h), but plasma clearance of the non-protein bound drug was reduced (115 vs. 243 ml×min^–1), plasma protein binding was reduced (92.8 vs. 97.2 percent), and the apparent volume of distribution was increased (0.20 vs. 0.141×kg^–1). In renal insufficiency plasma half-life was prolonged 2 to 6-fold, depending on the degree of renal impairment. Total plasma clearance (3.4 vs. 7.1 ml×min^–1) and plasma clearance of the unbound drug (81 vs. 243 ml×min^–1 were reduced in patients with renal failure, the clearance of the unbound drug being inversely correlated with the serum creatinine concentration. Renal failure was also associated with decreased protein binding and an increased volume of distribution of CPIB, and with reduced urinary excretion of CPIB and its glucuronide metabolite. The dose of clofibrate should be halved in patients with cirrhosis. In renal insufficiency, the dose should be adjusted according to the individual serum creatinine level: only 10 to 15% of the usual weekly dose should be given in complete renal failure.