Pharmacokinetics of lisinopril in hypertensive patients with normal and impaired renal function

Summary The pharmacokinetics of lisinopril was studied after administration of single and multiple doses of 5 mg to hypertensive patients with normal and impaired renal function.In patients with severe renal failure the peak concentrations were higher, the decline in serum concentration was slower and the time to peak concentration was extended. Accumulation of lisinopril was highly correlated with the creatinine clearance. The effective half-life was doubled and tripled in patients with mild and severe renal impairment, respectively, as compared to patients with a normal renal function. Lisinopril lowered blood pressure in all three groups over 24 h.It is suggested that smaller doses of lisinopril should be administered to patients with severe renal failure.     

Pharmacokinetics and pharmacodynamics of candesartan cilexetil in patients with normal to severely impaired renal function

Objective: We studied the pharmacokinetics and pharmacodynamics of single and multiple doses of candesartan cilexetil 8 mg per day in hypertensive patients with different degrees of renal function impairment. Candesartan is an angiotensin II subtype 1 (AT1) receptor antagonist that is administered orally as candesartan cilexetil which is converted in the active compound. Methods: Twenty-three patients were included, divided into groups according to creatinine clearance (cr cl. group A >60 nl · min⁻¹ · 1.73 m⁻², group B 30–60 ml · min⁻¹ · 1.73 m⁻² and group C 15–30 ml · min⁻¹ · 1.73 m⁻²). Results: Trough serum concentrations of candesartan were higher in group C compared with group A. The values did not increase after multiple dosing, indicating absence of accumulation. There was a significant negative correlation between the area under the concentration-time curve extrapolated to time infinity (AUC_inf) and the glomerular filtration rate (GFR) indicating a lower renal clearance of candesartan in patients with impaired renal function. The onset of haemodynamic and hormonal effects was gradual. During the single-dose study blood pressure as well as plasma renin activity (PRA) and angiotensin II were unchanged at peak. At day 5 of the multiple-dose study blood pressure was lower and both PRA and angiotensin II were higher compared with baseline. Conclusion: Although serum trough levels increased during repeated administration and half-life was higher in patients with impaired renal function, candesartan cilexetil at a dose of 8 mg per day does not lead to drug accumulation in these patients. This dose is effective in lowering blood pressure and appears to be suitable for patients with renal function impairment. Received: 3 August 1998 / Accepted in revised form: 19 October 1998     

Pharmacokinetics and antihypertensive effects of lisinopril in hypertensive patients with normal and impaired renal function.

The antihypertensive effects and pharmacokinetic properties of lisinopril, an angiotensin-converting enzyme (ACE) inhibitor, were investigated in hypertensive patients with normal renal function (NRF, mean serum creatinine 1.0 mg/dl, n = 9) and those with impaired renal function (IRF, mean serum creatinine 1.7 mg/dl, n = 8). Lisinopril was administered orally (10-mg dose once daily for 5 or 8 days). Measurement of blood pressure (BP) and sampling of blood specimens were made on the first and last days of treatment. During consecutive dosing of lisinopril, its antihypertensive effects were sustained for greater than or equal to 12 h with less diurnal variation of BP. Serum ACE activity was markedly suppressed for 24 h. Plasma levels of lisinopril in the IRF group were higher than those in NRF with significant differences in the peak levels and areas under the plasma concentration time curve (AUC). A significant inverse correlation was found between the creatinine clearance and the AUC for lisinopril. These results suggest that lisinopril has a long-lasting action and that it is a useful antihypertensive agent for controlling BP in patients with either NRF or mild IRF. When administered for an extended period, however, more careful consideration should be given to the dose in patients with IRF than in patients with NRF to minimize the possibility of untoward side effects.     

Pharmacokinetics of nicorandil in patients with normal and impaired renal function

Summary The pharmacokinetics of oral nicorandil 20 mg 12 hourly for 9 doses was evaluated in 21 hospitalized patients with angina pectoris due to coronary heart disease and with normal and impaired renal function. Patients were divided into 3 groups based on creatinine clearance (CL_Cr): GROUP I (n=6) > 80 ml/min, GROUP II (n=8) 20–80 ml/min, and GROUP III (n=7) < 20 ml/min.After the first dose, the total clearance of nicorandil (CL) value did not change with increasing renal failure and so was not dependent on creatinine clearance. After the last dose CL was 51 l·h^–1 in Group I, 44 l·h^–1 in Group II and 56 l·h^–1 in Group III, and it was not related to creatinine clearance. The percentage of the dose excreted in the urine was 0.4%. No significant difference was noted in any of the other pharmacokinetic parameters examined in the three groups, not even on comparing values obtained on the first and last days of treatment.The findings suggest that there is no need to change the dose of nicorandil in subjects with different degrees of renal failure.     

Pharmacokinetics of cephacetrile in patients with normal or impaired renal function

Summary The pharmacokinetics of cephacetrile, administered as a single i. v. injection of 15 mg/kg, have been determined in 8 patients with normal renal function and in 12 patients with a varying degree of renal impairment. A two-compartment model was used to describe the biphasic decline in serum concentrations and to calculate the amount of antibiotic in the central and peripheral compartments. In patients with normal renal function the following values were obtained for various pharmacokinetic parameters: =3.971 h^–1; =0.343 h^–1; K₁₂=1.745 h^–1; K₂₁=0.763 h^–1; K_el=1.793 h_–1; V_c=8.181; V_p=18.401 and V_dss=26.581. Cephacetrile had some of the highest apparent distribution volumes of all the cephalosporins. Impaired renal function significantly affected , , K₁₂, and K_el. A linear relationship between K_el of cephacetrile and creatinine clearance was demonstrated. The elimination of cephacetrile in anuric patients was about ten times slower than in patients with normal renal function.     

Pharmacokinetics of cefoxitin in patients with normal or impaired renal function

The pharmacokinetics of cefoxitin have been determined after a single i.v. injection of 15 mg/kg body weight in 10 patients with normal renal function and 20 patients with varying degrees of renal impairment. The kinetics of the antibiotic followed an open two-compartment model. In patients with normal renal function the following pharmacokinetic parameters were found: alpha = 8.66 h-1 beta = 1.21 h-1 K12 = 3.47 h-1 K21 = 3.17 h-1 K13 = 3.15 h-1 Vc = 4.24 l. Vp = 4.87 l. Vdss = 9.11 l. In the patients with renal impairment there was a significant decrease in alpha, beta, K12, K21 and K13, and an increase in the apparent volume of distribution. The degree of plasma protein binding in patients with normal renal function was 73.6% and this was diminished in patients with renal impairment. A linear relationship between K13 of cefoxitin and creatinine clearance was demonstrated. The dosage regimen for patients with renal impairment should be adjusted by modifying the dosage interval whilst maintaining the amount administered.     

Pharmacokinetics of cetamolol in hypertensive patients with normal and compromised renal function

The efficacy, safety, and pharmacokinetic parameters of a 30-mg oral dose of cetamolol hydrochloride (Betacor), a new synthetic cardioselective beta-adrenoceptor antagonist, with intrinsic sympathomimetic activity, were evaluated by studying 32 hypertensive patients with normal renal function or different degrees of renal impairment. After administration of cetamolol, serial blood and urine sample collections, as well as vital sign determinations for the next 48 hours, were performed in all patients (with the exception of urine collection, which was not possible in hemodialysis patients). Results indicate that cetamolol's pharmacokinetic parameters are significantly changed in patients who have moderate or severe renal impairment. Specifically, as the severity of renal impairment increased, the maximum serum concentration (Cmax) and the area under the serum concentration-time curve (AUC) increased, whereas the renal clearance (CLR), urinary excretion, and total body clearance (CL) decreased. Additionally, significant direct or inverse correlations for AUC, CL, CLR, and urinary excretion with creatinine clearance (CLCR) were demonstrated. In the subjects with mild renal impairment, the trends toward changes in the cetamolol pharmacokinetic parameters were evident, though small and not statistically significant. Although anuric, patients on hemodialysis still retained the ability metabolically to clear cetamolol at a rate of about one-third of that found in normal subjects. Reductions in blood pressure and heart rate also were found to be greater and more prolonged as the severity of renal impairment increased. There were no adverse drug or toxic effects noted in any of the study patients. Based on these findings, dosing recommendations are suggested for patients who have compromised renal function because of the effects of renal function on the pharmacokinetics of cetamolol.     

硫酸奈替米星在肾功能受损时的药物动力学

目的：测定不同肾功能患者体内单剂量静脉滴注５ｍｇ·ｋｇ－１硫酸奈替米星（ＮＴＭ）后的血清药物浓度，并计算药物动力学参数；同时测定了尿药浓度及原形药物回收率。方法：采用高效液相色谱－间接光度检测（ＨＰＬＣ－ＩＰＤ）法，以烟酰胺为检测剂，庚烷磺酸钠为反离子。结果：ＮＴＭ在肾功能正常组和受损组的Ｔ１／２β分别为３．５±１．４ｈ和５．８±１．４ｈ，ＡＵＣ０～２４ｈ６３．４±３２．１ｍｇ·ｈ·Ｌ－１和８９．５±３５．９ｍｇ·ｈ·Ｌ－１，２４ｈ尿中回收率也有明显差异。结论：表明肾功能受损患者每２４ｈ给药一次体内仍有蓄积     

Pharmacokinetics of felodipine in patients with impaired renal function.

1. The pharmacokinetics of felodipine and its effects on blood pressure and heart rate were studied in eight male patients aged between 28 and 57 years with a glomerular filtration rate, GFR, between 8 and 68 ml min-1, following single i.v. and oral administration. 2. Clearance, Cmax, AUC, Vss and V, of felodipine were unaffected by the renal disease. The metabolite excretion (14C-labelled) was slower than in healthy subjects. Initial renal clearance of these metabolites correlated with individual GFR values. The total amount of the dose excreted in the urine was also decreased.     

Pharmacokinetics of pefloxacin in normal and impaired renal function

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)     

Pharmacokinetics of Cefmenoxime in normal and impaired renal function

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.     

Pharmacokinetics of glucarpidase in subjects with normal and impaired renal function

Glucarpidase (formerly known as carboxypeptidase G2 or CPG2) is being evaluated for the adjunctive treatment of patients experiencing, or at risk of, methotrexate toxicity attributable to its delayed elimination. Delayed elimination of methotrexate can occur in patients with methotrexate-induced renal toxicity. In this study, glucarpidase pharmacokinetics were assessed in volunteer subjects with normal (n = 8) and severely impaired (n = 4) renal function. Each subject received a single intravenous dose of glucarpidase 50 U/kg (equivalent to 114.5 microg/kg) infused over 5 minutes. The mean maximum serum concentration (C(max)) for glucarpidase in renally impaired subjects was 2.9 microg/mL, the mean half-life (t(1/2)) was 10.0 hours, and the mean area under the serum concentration-time curve from time zero to infinity (AUC(0-infinity)) was 24.5 microg x h/mL. Similar values were found in subjects with normal renal function (mean C(max) 3.1 microg/mL, mean t(1/2) 9.0 hours, and mean AUC(0-infinity) 23.4 microg x h/mL). The results indicated little effect of renal impairment on the serum pharmacokinetics of glucarpidase.     

Pharmacokinetics of aspoxicillin in subjects with normal and impaired renal function

The pharmacokinetics of aspoxicillin [2S,5R,6R)-6-[(2R)-2-[(2R)-2-amino-3-(methylcarbamoyl)propionam ido]-2- (p-hydroxyphenyl)acetamido]penicillanic acid) in 10 subjects with normal kidney function and in 20 patients suffering from impaired renal function were examined after an i.v. short-term infusion of 4 g for a period of 20 min. In contrast to available semi-synthetic penicillins, aspoxicillin shows a slightly longer half-life elimination. As the substance is mainly excreted renally, the areas under the curve (AUC) are larger in cases of impaired renal function. Mathematical correlations can be established between the AUC and the renal function parameters creatinine and glomerular filtration rate. Dosage reduction factors are then derived which allow appropriate dosages to be established for the substances under examination. Dosages for differing degrees of impaired renal function are given in tables. Since sufficiently high and long-lasting urine levels are achieved, it is reasonable to use aspoxicillin as treatment of urinary tract infections in patients suffering from end-stage renal failure.     

Pharmacokinetics and haemodynamic effects of the angiotensin converting enzyme inhibitor cilazapril in hypertensive patients with normal and impaired renal function

1 The pharmacokinetic and pharmacodynamic properties of the angiotensin converting enzyme (ACE) inhibitor cilazapril were studied in 30 hypertensive patients with various degrees of renal function.
2 After a single oral dose, apparent cilazaprilat clearance was dependent on renal function being 16.0±3.0, 11.1 ± 3.0, 8.7 ± 3.7 and 6.7 ± 2.1 l h^-1 (means ± s.d.) in patients with creatinine clearances (CL_cr) of > 100, 41-100, 21-40, and 8-20 ml min^-1, respectively.
3 During 11 weeks of treatment with cilazapril, doses were adjusted to the CL_cr and varied from 0.5 to 5.0 mg once daily. At 24 h after drug administration a clear antihypertensive response was seen only in the low clearance groups (CL_cr < 40ml min^-1). In contrast, and despite higher once daily dosages, the decline of mean arterial pressure was small and cilazaprilat concentrations after 24 h were lower in the high clearance groups.
4 This study demonstrates that chronic once daily treatment with cilazapril is effective in patients with impaired renal function at dosages adjusted to creatinine clearance. No accumulation was seen. Since cilazaprilat clearance was high in the high creatinine clearance groups, a clear antihypertensive response in these groups was only seen at 3 h after drug administration.     

Pharmacokinetics of naproxen in subjects with normal and impaired renal function

Summary The pharmacokinetics of naproxen after a single oral dose of 250 mg has been studied in 8 subjects with normal renal function and 16 patients with varying degrees of chronic renal insufficiency. Unchanged naproxen and its main unconjugated metabolite, 6-0-desmethylnaproxen, were determined fluorometrically in serum. In healthy subjects the elimination half-life of naproxen was 17.7± 3.0 h (mean±SD) and it was not significantly prolonged in patients with renal failure (18.1±5.3) h. No accumulation of naproxen in serum occurred in uraemic patients. On the contrary, serum drug levels were slightly but significantly lower in patients with severe renal failure. The total body clearance and apparent volume of distribution of naproxen were significantly increased in this group of patients. Decreased binding of naproxen to serum proteins was observed in patients with renal failure. The apparent half-life of desmethylnaproxen was of the same order of magnitude as that of naproxen (18.6± 4.4 h), and was also independent of renal function. A good correlation was found between the area under the curve (AUC), the peak concentration of the metabolite and the serum creatinine concentration. These observations suggest increased metabolism and an increased apparent volume of distribution of naproxen in severe renal failure, probably caused by decreased serum protein binding of the drug. However, it is proposed that in naproxen therapy no adjustment of the dosage regimen is necessary in patients with impaired renal function.     

Pharmacokinetics of cicletanine in patients with impaired renal function

The pharmacokinetics of cicletanine were studied in 43 patients with chronic renal failure of various degrees, including six patients treated by maintenance haemodialysis, following single oral administration of either 300 or 200 mg. A repeated-dose study was performed at the start and at the end of daily oral administration of 200 mg for 30 days in six patients with moderate renal dysfunction. The pharmacokinetics of cicletanine were markedly altered in patients with severe impairment of renal function (i.e., creatinine clearance under 30 ml/min/1.73 m2 or treated by chronic haemodialysis) with a significant increase in elimination half-life and tissue accumulation of the drug. In contrast, only minor alterations in the pharmacokinetic parameters were observed in patients with mild or moderate renal failure, even after repeated administration of the drug. In conclusion, the use of cicletanine should be restricted, on the basis of these pharmacokinetic data, to chronic uremic patients whose creatinine clearance is 30 ml/min/1.73 m2 or more.     

Pharmacokinetics of carteolol in patients with impaired renal function

Summary In order to determine the appropriate dosage of carteolol in renal dysfunction, the pharmacokinetics of carteolol has been examined in appropriate patients. The plasma concentrations and urinary excretion of carteolol were investigated in 15 patients with varying degrees of renal impairment during the administration of 5–20 mg carteolol hydrochloride (5 mg/tablet) for 2–45 months.Plasma carteolol levels were linearly correlated with the serum creatinine concentration (r = 0.87) and reciprocally with the creatinine clearance (r = 0.82). The urinary carteolol concentration was correlated with the urinary creatinine concentration (r = 0.69) and the urinary carteolol excretion was also correlated with the creatinine clearance (r = 0.79). These relationships become even closer when the plasma carteolol concentrations and urinary excretion rate of carteolol were factored by the administered tablets. The fractional renal excretion of carteolol was virtually constant at various degress of renal function, and it always exceeded 100%, which indicates that carteolol was actively secreted, even in patients with renal failure. The estimated tubular secretion rate of carteolol was logarithmically correlated with the fractional renal excretion of carteolol (r = 0.93).The results indicate that the dose of carteolol should be determined according to the degree of renal impairment.     

Pharmacokinetics of cefixime in patients with impaired renal function

Cefixime (CFIX) was given orally in a single dose of 100 mg to 7 patients with varying degrees of impaired renal function (Ccr 12.0-56.7 ml/min) and serum concentrations and urinary excretion rates were measured with time for the first 24 hours by the bioassay method to investigate in vivo pharmacokinetics of the drug. The results obtained are summarized as follows. The mean peak serum concentration of CFIX in 3 patients with moderately impaired renal function (group I: Ccr greater than or equal to 30-less than 60 ml/min) was 2.04 micrograms/ml at 6 hours after dosing and gradually declined to 0.10 microgram/ml at 24 hours after dosing. The half-life was 4.15 hours. The mean peak serum concentration of CFIX achieved was 2.27 micrograms/ml at 8 hours after dosing in 4 patients with severely impaired renal function (group II: Ccr greater than or equal to 10-less than 30 ml/min) and the concentration of CFIX was 0.99 microgram/ml even after 24 hours. The half-life was prolonged to 11.05 hours. There was no great difference between groups I and II in the first 24-hour urinary excretion rates. However, the first 4-hour urinary excretion accounted for 2.14% of the administered dose of CFIX in group I but only 0.47% in group II. Urinary concentrations of CFIX peaked at 4-6 hours after dosing in both groups, and thereafter gradually decreased in group I. Whereas, they did not decline much in group II until 24 hours after dosing.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pharmacokinetics and pharmacodynamics of benazepril hydrochloride in patients with major proteinuria

Summary We have investigated whether the pharmacokinetics and pharmacodynamics of the ACE inhibitor benazepril hydrochloride are altered with proteinuria by studying 8 patients with major proteinuria of different causes who were given a single dose of 10 mg p.o.The maximum plasma concentration of benazepril was found between 0.5 and 2 h after dosing (median 1 h). Its elimination was almost complete within 6 h. Peak plasma levels of benazeprilat, the active metabolite of benazepril, were observed between 1 and 6 h (median 2.5 h). The elimination of benazeprilat from plasma was biphasic, with mean initial and terminal half-lives of 3.0 and 17.3 h, respectively. On average, the pharmacokinetic parameters of benazepril and benazeprilat in the patients did not differ from those in a historical control group of healthy volunteers, but intersubject variability in the AUC and half-lives of benazeprilat was greater in the patients.Plasma ACE was completely inhibited from 1.5 to 6 h after dosing, and at 48 h the mean inhibition was still 42 %. Plasma renin showed substantial intersubject variation. Mean supine blood pressure (systolic/diastolic) was reduced from baseline by a maximum of 18/13 mm Hg at 6 h. Proteinuria was diminished after benazepril in 7 patients.In conclusion, the results of this study suggest that proteinuria in the nephrotic range does not require a change in benazepril dosage.     

Pharmacokinetics of tenoxicam in patients with impaired renal function

Summary The pharmacokinetics of tenoxicam after a single oral dose of 20 mg has been studied in 12 patients with various degrees of decreased renal function. Unchanged tenoxicam and its 5OH-metabolite in plasma and urine were determined by HPLC. The mean areas under the plasma concentration-time curve (138±53 µg/ml·h) and terminal half-lives in patients with impaired renal function did not differ from values previously reported in normal volunteers, nor did the peak concentration of tenoxicam. The half-life of 5OH-tenoxicam and unchanged tenoxicam where the same. The urinary excretion of 5OH-tenoxicam fell with decreasing renal function. Thus no dosage adjustment should be necessary and the usual daily dose of tenoxicam may be administered once daily also to patients with renal failure.