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1.
AIMS: To compare raloxifene pharmacokinetics between renally impaired and healthy subjects. METHODS: Raloxifene 120 mg was administered to 10 males with renal impairment (creatinine 2-4 mg dl(-1)) and to 10 healthy males. Data were analysed by two noncompartmental and one compartmental nonlinear regression methods. RESULTS: The medians (95% confidence interval) of the area under the curves (AUC) were 35.1 (25.8, 74) and 20.5 (16.8, 28.0) h ng ml(-1) per mg kg(-1), P < 0.01, and of the clearances (CL/F) were 28.5 (13.5, 38.8) and 48.8 (35.8, 59.4) l h(-1) kg(-1), P < 0.01, in renally impaired and healthy subjects, respectively. 95% Confidence intervals on the differences for AUC and CL/F were 6.5-44.1 and -35.1 to -7.9, respectively. CONCLUSION: Exposure to raloxifene was twice as high in males with renal impairment compared with healthy subjects.  相似文献   

2.
Pharmacokinetics of latamoxef (Moxalactam) have been investigated in 10 normal volunteers and 20 patients with impaired renal function after i.v. injection of 2 g. Elimination observed in normal volunteers can best be described by a two-compartment model. In the presence of impaired renal function elimination of latamoxef is markedly prolonged. The result is a larger area under the serum level curve (area under the curve; AUC). AUC and glomerular filtration rate (as well as AUC and plasma creatinine as approximate measure of renal function) can be brought into a mathematical relation. From these relations a dose reduction factor (DRF) can be derived. By means of this factor a dose can be calculated for each arbitrary degree of renal impairment which causes the same AUC that would be anticipated in a subject with normal renal function. Dosing proposals are given in tabular form. These allow to bring about, that in each conceivable degree of renal failure, an AUC would be reached as it would have been attained in normal subjects.  相似文献   

3.
The steady-state pharmacokinetics of nefazodone (NEF) and its metabolites hydroxynefazodone (HO-NEF) and m-chlorophenylpiperazine (mCPP) were compared in subjects with normal and impaired renal function. Patients: The Study was of parallel group design which included 7 subjects with normal (NOR) renal function, CLCR72 ml·min–1·1.73 m–2, 6 with moderate (MOD) renal impairment, CLCR 31–60 ml·min–1·1.73 m–2 and 9 with severe (SEV) renal impairment, CLCR30 ml·min–1·1.73 m–2. Subjects in each renal function group received a 100-mg oral dose of nefazodone hydrochloride BID for 7 days and a single morning dose on day 8. Starting 48 h after the last 100-mg dose, 200-mg doses were administered on a similar schedule to 3, 4 and 3 subjects from each renal function group (NOR, MOD and SEV, respectively). Single trough blood samples just prior to each morning dose (Cmin) and serial samples after the dose on day 8 were obtained at each dose level for pharmacokinetic analysis. Plasma samples were assayed by a specific HPLC method for NEF, HO-NEF and mCPP.The CMIN data indicated that steady state was attained by the third day of BID administration of both the 100- and 200-mg doses of nefazodone, regardless of degree of renal function. Both NEF and HO-NEF attained steady-state Cmax within 2 h after administration of nefazodone; tmax for mCPP was less defined and more delayed. HO-NEF and mCPP plasma levels were about 1/3 and <1/10 those of NEF, respectively, regardless of the status of renal function. Steady-state systemic exposure of NEF and HO-NEF, as reflected by AUC and Cmax, and elimination t1/2 values did not differ significantly among renal function groups. Conclusion: The study results suggest that dose adjustments may not be necessary, but nefazodone should be used with caution in the presence of severe renal impairment.  相似文献   

4.
5.
Summary The pharmacokinetics of the new lipidlowering drug bezafibrate has been investigated in patients with impaired renal function and hyperlipoproteinaemia. 12 patients received a single oral dose of bezafibrate 300 mg. Plasma and urine samples were collected and bezafibrate was analyzed by gas chromatography. Eight of the patients had moderately impaired renal function, with a creatinine clearance between 20 and 40 ml/min; the mean plasma half-life of bezafibrate in them was 7.8±3.9 h (SD) and the plasma clearance was 0.03±0.02 l/kg · h. Three of the patients had a creatinine clearance>40 ml/min; in them the plasma half-life was shorter, 4.6±1.2 h, and the plasma clearance was higher, 0.06±0.01 l/kg · h. The slowest elimination of bezafibrate was found in a patient with a creatinine clearance of only 13 ml/min. This patient had a plasma half-life of 20.1 h, which is ten times longer than has been reported in healthy volunteers. Thus, when treating hyperlipoproteinaemia in patients with impaired renal function, the dosage of bezafibrate must be individualized because of its reduced renal elimination.  相似文献   

6.
Many antibiotics are eliminated renally and dosage adjustments are commonly made in patients with renal insufficiency. This is a critical review of antibiotic pharmacokinetics in patients with various degrees of renal function. Detailed information regarding pharmacokinetic alterations with specific antibiotics or antibiotic classes has been compiled and tabulated. From pharmacokinetic evidence, recommendations for dosage adjustments of antibiotics are supplied. The criteria used for assigning rating levels to specific pharmacokinetic articles as well as the grading system for dosage adjustments are outlined. In addition, a basic review of pharmacokinetic alterations in renal failure and factors affecting the removal of drugs by haemodialysis is included.  相似文献   

7.
12 patients with mild to moderate impairment of renal function and 12 healthy subjects each received 20mg buspirone as a single dose in this acute study. Six anuric patients with chronic renal failure were given two 20mg doses of buspirone, the first 2 days before haemodialysis (between dialyses) and the second during hemodialysis (2 hours before dialysis began). The differences between the median pharmacokinetic values of buspirone for healthy subjects, patients with mild to moderate renal impairment, and anuric patients were not statistically significant. Similarly, there were no significant differences between values in mild to moderate renal failure vs healthy subjects. Some of the median pharmacokinetic values for the active buspirone metabolite 1-(2-pyrimidinyl)-piperazine (1-PP), however, differed significantly for anuric patients, compared with healthy subjects or patients with mild to moderate renal impairment. When assessed between and during haemodialysis, the anuric patients had significantly (p less than 0.05) greater pharmacokinetic median values: half-life (t 1/2) = 15.2 vs 9.8 hours; area under the concentration-time curve (AUC) = 604 vs 404 nmol/L.h; and mean residence time (MRT) = 9.28 vs 6.96 hours. No firm recommendation for specific dosage can be made based on the present data. However, it does appear that in patients with mild to moderate renal impairment, the pharmacokinetics of buspirone and its active metabolite 1-PP are similar to those in individuals with normal renal function. For anuric patients higher concentrations of the 1-PP metabolite are attained while they are not undergoing haemodialysis. A dosage reduction of 25 to 50% might be necessary when buspirone is given to anuric patients.  相似文献   

8.
The bioavailability and pharmacokinetics of cimetidine were studied following single oral and intravenous doses in subjects with severely impaired renal function (SIRF) and normal renal function (NRF). Eight subjects with NRF and five patients with SIRF participated. Multiple blood samples were obtained up to 1440 minutes following both doses. Urine was also collected for 24 hours after each dose. The bioavailability of cimetidine was not significantly different between the two groups (78 +/- 15% in patients with SIRF and 62 +/- 17% in the NRF subjects). In subjects with NRF, a mean of 50.4% of the i.v. dose was excreted renally as unchanged drug and the mean serum half-life (t1/2) was 2.00 hours. The mean total body and renal clearances were 710.0 and 370.7 ml/min, respectively. In the SIRF group, a mean of 1.7% of the i.v. dose was excreted renally unchanged, and the mean t1/2 was 12.71 hours. The total body and renal clearances were 147.1 and 2.5 ml/min, respectively. Nonrenal clearance was 62% lower in the subjects with SIRF than in the NRF subjects. There is no significant difference in bioavailability of cimetidine between the patients with NRF and SIRF. The significantly lower nonrenal clearance of the patients with SIRF suggests that cimetidine metabolism may be impaired in uremic patients.  相似文献   

9.
Summary The pharmacokinetics of the enantiomers of nitrendipine has been studied in seven elderly patients with chronic renal failure (CRF) and in six control subjects (mean creatinine clearance 30 and 97 ml·min–1 respectively). Racemic nitrendipine 20 mg was given once daily for seven days and the pharmacokinetics of the enantiomers over the last dosage interval were determined using a stereospecific assay.In both groups nitrendipine exhibited stereoselective pharmacokinetics (AUC, Cmax), but the half-lives of the enantiomers did not differ in individual subjects. As an index of stereoselectivity, the mean S/R ratio of AUCs in control subjects (2.07) was not significantly different from the ratio in patients with CRF (2.68).The mean AUCs of (S)- and (R)-nitrendipine during the last dosage interval were increased in CRF by 132% and 85%, respectively. The observed doubling of the half-lives and the increases in Cmax did not reach significance because of the large variability in each group.Thus, the pharmacokinetics of oral nitrendipine is altered in CRF, but there was no change in the stereoselectivity of its pharmacokinetics.  相似文献   

10.
Oral flecainide pharmacokinetics in patients with impaired renal function   总被引:1,自引:0,他引:1  
The pharmacokinetics of flecainide acetate were studied in 20 patients with varying degrees of renal impairment following a single oral dose. The patients were divided into two groups, on the basis of renal creatinine clearance (CLCR), for statistical and kinetic analysis. Patients with a CLCR between 4 and 41 mL/min/m2 were designated group 1 and those below 4 mL/min/m2 or unmeasurable because of lack of urine output were designated group 2. In both groups peak plasma flecainide concentrations, time to peak concentrations, and apparent volume of distribution (Vd) were similar to those reported in healthy subjects with normal renal function. The mean flecainide plasma elimination half-lives from both groups 1 and 2 were longer than those previously reported by several investigators in normal subjects. Nine patients in group 1 and seven patients in group 2 had half-lives within the range reported in healthy subjects. Therefore, CLCR alone is not a good predictor of plasma elimination half-life following a single oral dose of flecainide. Although renal clearance of flecainide is significantly reduced in end-stage renal disease (ESRD), total plasma clearance of flecainide (CLflec) was not reduced to the same degree, although there was a significant, modest correlation with CLCR. Less than 1% of the administered oral dose of flecainide was removed during hemodialysis. The relationship between dosage and plasma elimination half-life in patients with ESRD needs further study to evaluate possible dose-dependent kinetics.  相似文献   

11.
Eighteen patients (14 men and 4 women, aged 36-74 years) treated with metoprolol for a month were included in the study. Twelve had impaired renal function (IRF) with a glomerular filtration rate (GFR) of 7.5-77.1 mL/min and six having normal renal function (NRF) with a GFR of 84.9-113.0 mL/min. Plasma and urine concentrations of felodipine and metabolites, heart rate, and blood pressure were recorded over 24 hours on day 1 after an oral dose of 10 mg felodipine and 0.04 mg 3H-felodipine IV and repeated on day 29 during continuous treatment with felodipine, 10 mg bid. The bioavailability of the oral dose on day 1 and day 29 was 13% and 12.5%, respectively. The terminal plasma half-life (t1/2) on day 29 was 22 hours and systemic clearance was 490 mL/min on day 1 and 434 mL/min on day 29 (NS). There were no differences in these parameters between NRF and IRF. The protein binding determined by equilibrium dialysis in the six patients with the lowest GFR was 99.74% on day 1 and 99.73% on day 29 and did not differ significantly from previously reported values in healthy subjects. The mean supine blood pressure before the acute dose of felodipine was 164/96 mm Hg in the IRF patients and 145/95 mm Hg in the NRF patients. A maximum decrease of 37/22 mm Hg and 32/19 mm Hg, respectively, was seen within 1.5 hours after dose and at 12 hours the reduction was 12/9 and 15/10 mm Hg, respectively, compared to baseline values. At steady state the morning blood pressure before dose was 152/87 mm Hg in the IRF patients and 129/86 mm Hg in the NRF patients. Similar maximum decreases and effects at 12 hours were seen after dose on day 29 as on day 1. Data on the effect on diastolic blood pressure and plasma felodipine concentrations were well fitted to the Emax model. The maximum reduction in diastolic blood pressure using this model was 27% and the plasma concentration leading to 50% of the maximum effect was 6.2 nmol/L. In conclusion, renal disease does not affect the pharmacokinetics of felodipine. The pharmacokinetic and pharmacodynamic effects of felodipine are not altered during steady state. The renal excretion of inactive metabolites is reduced in IRF. However, the accumulation of metabolites in the blood does not affect the protein binding or the clearance of felodipine. No dosage adjustment of felodipine seems to be necessary in patients with hypertension and renal impairment.  相似文献   

12.
Following a single oral dose of 20 mg nifedipine combined with 2 mg co-dergocrine to 24 subjects, the pharmacokinetics of this drug were studied. 8 normotensive subjects had normal renal and hepatic function, 8 patients had chronic renal insufficiency (creatinine clearance less than 30 ml.min-1) and 8 patients had liver cirrhosis which was confirmed by liver biopsy. The area under the plasma level time curve (AUC infinity) of co-dergocrine increased from 0.59 +/- 0.41 ng.ml-1. (mean +/- SD) in the normals to 1.24 +/- 0.95 ng.ml-1.h in liver cirrhosis (P less than 0.05) and to 1.81 +/- 0.9 ng.ml-1.h in renal failure (P less than 0.05 compared with the control group). Corresponding values for the nifedipine AUC infinity were 564.5 +/- 268 ng.ml-1.h, 1547.5 +/- 1134 (P less than 0.05) and 929 +/- 533 ng.ml-1.h (P less than 0.05; gas chromatographic method). The incidence of adverse effects was lower in patients with renal failure than in subjects with normal renal and liver function as well as in those with liver cirrhosis.  相似文献   

13.
The authors have investigated the pharmacokinetics and tolerability of regadenoson, a selective A2A adenosine receptor agonist for use in drug-stressed myocardial perfusion imaging in subjects with varying degrees of renal function. Sixteen subjects with different creatinine clearance values (range: 15-132 mL/min) received a single intravenous bolus dose of 400 microg regadenoson. A population pharmacokinetic model was developed to describe the pharmacokinetics of regadenoson in these subjects. Regadenoson elimination half-life was prolonged with decreasing renal function. However, maximum plasma concentrations, number, or severity of adverse events did not differ significantly between the subjects. Heart rate increased in all subjects after regadenoson injection but returned to normal within 150 minutes. There were no blood pressure pattern differences with respect to renal function. Results from this study do not indicate that dose adjustments are necessary when subjects with decreased renal function are administered the clinically relevant dose of 400 microg regadenoson.  相似文献   

14.
1 The pharmacokinetics of cimetidine and its sulphoxide metabolite was studied after a single intravenous dose of 200 mg cimetidine in nine patients with normal renal function and ten patients with severe renal failure on regular haemodialysis and during continuous oral cimetidine treatment in ten patients with normal renal function and 31 patients with different degrees of renal failure. 2 In normal renal function a mean of 47.3% of the single intravenous dose was excreted as unchanged drug and 12.8% as cimetidine sulphoxide. The mean plasma elimination half-life (T1/2) of cimetidine was 2.0 h and of cimetidine sulphoxide 1.7 h. 3 In severe renal failure a mean of 2.2% of the single intravenous dose was excreted as unchanged drug and 0.5% as cimetidine sulphoxide. The mean plasma T1/2 of cimetidine was 3.9 h. The plasma concentrations of the sulphoxide metabolite increased successively with time after dosing and no elimination phase was observed still 9 h after dose. The mean non-renal clearance of cimetidine was 210 ml/min and lower than in normal renal function, suggesting decreased metabolism of cimetidine in uraemia. 4 During continuous oral cimetidine treatment in patients with normal renal function and in patients g and no elimination phase was observed still 9 h after dose. The mean non-renal clearance of cimetidine was 210 ml/min and lower than in normal renal function, suggesting decreased metabolism of cimetidine in uraemia. 4 During continuous oral cimetidine treatment in patients with normal renal function and in patients g and no elimination phase was observed still 9 h after dose. The mean non-renal clearance of cimetidine was 210 ml/min and lower than in normal renal function, suggesting decreased metabolism of cimetidine in uraemia. 4 During continuous oral cimetidine treatment in patients with normal renal function and in patients with different degrees of renal failure given reduced doses of cimetidine the plasma concentrations of the sulphoxide metabolite were higher with decreasing renal function. The mean plasma T1/2 of cimetidine was 3.1 h in mild renal dysfunction (creatinine clearance 50-75 ml/min) and 4.5 h in severe renal failure (creatinine clearance 5-15 ml/min) and of cimetidine sulphoxide 5.3 and 14.4 h respectively. 5 Toxicity studies of cimetidine sulphoxide may be needed to assess if high plasma concentrations of the sulphoxide metabolite in severe renal failure are of clinical significance.  相似文献   

15.
Pharmacokinetics of pefloxacin in normal and impaired renal function   总被引:1,自引:0,他引:1  
Ten healthy young volunteers (mean age 28 years) and 24 patients (mean age 54 years) suffering from various degrees of chronic renal failure received an infusion of 400 mg pefloxacin (1-ethyl-6-fluoro-1, 4-dihydro-7-(4-methyl-1-piperazinyl)-4-oxo-3-quinolinecarboxylic acid) over 30 min. The blood and urine levels of pefloxacin and of the two metabolites pefloxacin-N-oxide and norfloxacin were determined using the HPLC method. Blood levels were taken after periods of 0, 60, 120, 180, 360, 600, 720, 1440, 2880, 3360 min, and in patients suffering from renal insufficiency also after 4320 min. The urine was collected and analyzed during the periods of 0-2, 2-4, 4-10 (12) h and then in longer periods up to 72 h. In all subjects, the glomerular filtration rate (GFR, by chrome-51-EDTA) and the plasma creatinine level were determined. Effective levels against bacteria lying in pefloxacin's spectrum can be found in the plasma for about 1.5 days and in the urine for about 2.5 days. Patients suffering from chronic renal failure have pefloxacin plasma levels which beyond 24 h are higher than in healthy persons. This can be explained by both: impaired renal and extrarenal elimination. The volume of distribution of the volunteer and the patient group does not differ significantly. Therapeutic urine levels could be found in patients up to 48 h after end of infusion. Even in patients requiring regular hemodialysis, therapeutic urine levels were found up to 24 h (if urine could be produced at all). The substance therefore is a suitable remedy for urinary infections in dialysis patients as well.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

16.
Pharmacokinetics of Cefmenoxime in normal and impaired renal function   总被引:1,自引:0,他引:1  
7 beta-[2-(2-Aminothiazol-4-yl)-(Z)-2-methoxy-iminoacetamido]-3-[(1- methyl-1H-tetrazol-5-yl)thiomethyl]-ceph-3-em-4-carboxylic acid hemihydrochloride (Cefmenoxime), a new cephalosporin with a broad spectrum of activity against gram-positive and gram-negative bacteria, was investigated pharmacokinetically. 10 healthy volunteers and 20 patients with renal disease each received 2 g of the substance i.v. The plasma levels were monitored for 6 h in healthy volunteers and for 24 h in the patients with renal disease. The analysis of the data showed that the majority of the curves could be properly evaluated only with the aid of a two-compartment model. Therefore a simple half-life cannot be given. Cefmenoxime is eliminated more rapidly than cefoperazone, but more slowly than cefotaxime. The area under the serum level curves (AUC) increases when renal function is impaired. There is a mathematical correlation between the AUC and the renal function parameters, plasma creatinine and glomerular filtration rate. This gives the dose reduction factors, allowing the calculation of the doses with the same AUC on restricted renal function as that observed in healthy persons after normal doses. Dosage recommendations are given in the form of tables regarding the questions 1. to what extent the dose may be reduced in impaired renal function without lowering the AUC and 2. what is the highest safe dose.  相似文献   

17.
This open-label study investigated whether drospirenone, a novel progestin with antimineralocorticoid properties, increases the risk for hyperkalemia in subjects with renal impairment. Women with normal renal function and mild or moderate renal impairment were given drospirenone 3 mg/d for 14 days. Mean serum potassium concentrations did not significantly change during steady-state drospirenone treatment. No difference in drospirenone effects on serum potassium concentrations in subjects with renal insufficiency versus subjects with normal renal function was found. Steady-state pharmacokinetics was similar in subjects with normal renal function and mild renal impairment, whereas, due to results from 1 subject, drospirenone exposure was slightly higher in the moderate renal impairment group. Given the reported tolerability of drospirenone, this small increase in serum drospirenone is not expected to be clinically significant. In conclusion, this study demonstrated that drospirenone has no significant effect on serum potassium levels in patients with mild to moderate renal insufficiency.  相似文献   

18.
AIMS: To evaluate the effect of renal impairment on the pharmacokinetics and safety of pioglitazone and its metabolites M-III and M-IV with impaired renal function and normal renal function. METHODS: In a phase-I, open-label, parallel-group study, six healthy subjects with normal renal function (creatinine clearance> 80 ml min-1), nine patients with moderate renal impairment (creatinine clearance 30-60 ml min-1) and 12 patients with severe renal impairment (creatinine clearance < 30 ml min-1) received single and multiple oral doses of pioglitazone 45 mg. The serum pharmacokinetic profiles of pioglitazone and its metabolites M-III and M-IV were assessed for the first and last dose administered (day 1 and day 12, respectively). RESULTS: Pharmacokinetic data revealed no significant accumulation of pioglitazone or its metabolites M-III and M-IV in patients with renal impairment. There was no significant difference in the pharmacokinetic profile of pioglitazone in subjects with normal and with moderately impaired renal function. After single oral doses, mean area under the concentration-time curve (AUC) values were decreased in patients with severe renal impairment compared with healthy subjects with normal renal function for pioglitazone (13 476 vs 17 387, P = 0.371; -23%; confidence interval (CI) -57, 38), M-III metabolite (13 394 vs 15 071, P = 0.841; -11%; CI -74, 194) and M-IV metabolite (27 991 vs 49 856, P = 0.006; -44%; CI -62, -17). After repeated oral doses of pioglitazone, mean AUC values (microg.h l-1) were decreased in patients with severe renal impairment compared with healthy subjects with normal renal function for pioglitazone (8744 vs 14,565, P = 0.004; -40%; CI -57, -16), M-III (3991 vs 7,289, P = 0.0009; -45%; CI -60, -25) and M-IV (21 080 vs 25 706, P = 0.181; -18%; CI 39, 10). The tolerability and safety profile of pioglitazone was comparable between groups. CONCLUSIONS: Pioglitazone was well tolerated in patients with varying degrees of renal impairment. Although mean serum concentrations of pioglitazone and its metabolites are increased in patients with severe renal impairment, adjustment of starting and maintenance doses in these patients is probably unwarranted.  相似文献   

19.
20.

Aims

This study aimed to describe lamivudine pharmacokinetics in patients with impaired renal function and to evaluate the consistency of current dosing recommendations.

Methods

A total of 244 patients, ranging in age from 18 to 79 years (median 40 years) and in bodyweight from 38 to 117 kg (median 71 kg), with 344 lamivudine plasma concentrations, were analysed using a population pharmacokinetic analysis. Serum creatinine clearance (CLCR) was calculated using the Cockcroft–Gault formula; 177 patients had normal renal function (CLCR > 90 ml min−1), 50 patients had mild renal impairment (CLCR = 60–90 ml min−1), 20 patients had moderate renal impairment (CLCR = 30–60 ml min−1), and five patients had severe renal impairment (CLCR < 30 ml min−1).

Results

A two-compartment model adequately described the data. Typical population estimates (percentage interindividual variability) of the apparent clearance (CL/F), central (Vc/F) and peripheral volumes of distribution (Vp/F), intercompartmental clearance (Q/F) and absorption rate constant (Ka) were 29.7 l h−1 (32%), 68.2 l, 114 l, 10.1 l h−1 (85%) and 1 h−1, respectively. Clearance increased significantly and gradually with CLCR. Our simulations showed that a dose of 300 mg day−1 in patients with mild renal impairment could overexpose them. A dose of 200 mg day−1 maintained an exposure close to that of adults with normal renal function. However, the current US Food and Drug Administration recommendations for lamivudine in other categories of patients (from severe to moderate renal impairment) provided optimal exposures.

Conclusions

Lamivudine elimination clearance is related to renal function. To provide optimal exposure, patients with mild renal impairment should receive 200 mg day−1 instead of 300 mg day−1.  相似文献   

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