瑞舒伐他汀联合厄贝沙坦对原发性高血压早期肾损伤患者肾脏功能及其他实验室指标的影响

目的 探讨瑞舒伐他汀联合厄贝沙坦对原发性高血压早期肾损伤患者肾脏功能及实验室指标的影响。方法 将原发性高血压早期肾损伤患者60例随机分为两组,分别给予厄贝沙坦单用(对照组)和与瑞舒伐他汀联用(试验组);比较两组患者肾功能及实验室指标,评价其临床疗效。结果 对照组患者治疗后总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白(LDL-C)及高密度脂蛋白(HDL-C)水平分别为(5.65±1.36)mmol/L、(2.18±0.85)mmol/L、(3.70±0.97)mmol/L、(1.18±0.63)mmol/L;试验组患者治疗后TC、TG、LDL-C及HDL-C水平分别为(3.94±0.80)mmol/L、(1.62±0.46)mmol/L、(2.26±0.64)mmol/L、(1.45±0.73)mmol/L;对照组患者治疗后血肌酐(Scr)、血尿素氮(BUN)及24 h尿白蛋白定量水平分别为(79.15±17.25)mmol/L、(5.37±1.07)mmol/L、(73.54±16.34)mmol/L;试验组患者治疗后Scr、BUN及24 h尿白蛋白定量水平分别为(75.70±14.84)mmol/L、(4.92±0.98)mmol/L、(57.32±12.94)mmol/L;试验组患者治疗后血脂和肾脏功能指标均显著优于对照组,差异有统计学意义(P<0.05);试验组患者治疗后β2-MG、Cys-C、hs-CRP及ET-1水平均显著低于对照组,差异有统计学意义(P<0.05)。结论 瑞舒伐他汀联合厄贝沙坦治疗原发性高血压早期肾损伤患者效果确切。     

Meloxicam pharmacokinetics in renal impairment

Aims The aim of the present study was to determine how the pharmacokinetics of meloxicam are affected by kidney dysfunction and consequently to define the appropriate dose for the use of meloxicam in patients with mild or moderate renal impairment.
Methods Meloxicam was administered to subjects with mild (creatinine clearance 41–60 ml min⁻¹) to moderate (20–40 ml min⁻¹) renal impairment compared with normal renal function (>60 ml min⁻¹). Thirty-eight subjects received meloxicam 15 mg once daily over 9 days. Meloxicam plasma concentrations were determined from blood samples taken during the study and pharmacokinetic parameters calculated according to noncompartmental methods.
Results Subjects with no or mild renal impairment showed sinular pharmacokinetic profiles (geometric mean AUC_SS (%gCV) 55 (33%) vs 55 (38%) μg ml⁻¹ h). Subjects with moderate renal impairment demonstrated lower total plasma meloxicam concentrations (AUC_SS 35 (50%) μg ml ⁻¹ h, with corresponding higher plasma clearance ( P = 0.013) compared with subjects with no renal impairment. However, this was combined with higher meloxicam free fractions in moderately impaired subjects such that free meloxicam concentrations were similar in all three groups. Meloxicam was well tolerated with few adverse events occurring and no difference in incidence observable between groups.
Conclusions On the basis of these results there is no necessity for a dosage adjustment when administering meloxicam to patients with mild to moderate renal impairment.     

The effect of renal function on the pharmacokinetics of ranitidine

This open study evaluated the influence of renal function on the pharmacokinetics of ranitidine (50 mg iv infusion given over 6 min). Five groups, each of 8 subjects, 1 with normal renal function and 4 with different degrees of renal impairment were studied.Renal function was assessed in each patient by ⁵¹Cr-EDTA (glomerular filtration rate, GFR), creatinine clearance (GFR) and N-methylnicotinamide clearance (reflecting glomerular and tubular function). Sixteen blood samples (5 ml) taken up to 48 h post dose from each subject were analysed for plasma ranitidine concentrations by reversed phase HPLC.Patient groups with renal impairment had significantly increased AUC and t_1/2 with corresponding decreases in CL_p and _z when compared with normal subjects. There was also a significant increase in t_max but not in C_max. There was a high linear correlation between the degree of renal impairment and ranitidine clearance.In patients with GFR 20 ml min^–1, the AUC mean ratio (compared with normal subjects) was up to 4.6 while for patients with GFR 20–50 ml min^–1, the average AUC ratio was 2.6. It is recommended that the dose of ranitidine is halved in patients with GFR 20 ml min^–1.     

Garenoxacin pharmacokinetics in subjects with renal impairment*

ABSTRACT

Objective: This open-label, parallel-group study determined the pharmacokinetics of garenoxacin in subjects with severe renal impairment, including subjects maintained on dialysis.

Research design and methods: Subjects were assigned to one of four groups according to their underlying renal function: creatinine clearance (CL_cr) > 80?mL/min, CL_cr < 30?mL/min, hemodialysis (HD), and continuous ambulatory peritoneal dialysis (CAPD). Subjects received a single oral 600?mg dose of garenoxacin. Administration of garenoxacin to subjects receiving hemodialysis was completed in two phases separated by 14 days: 3?h before HD (phase 1) and immediately after HD (phase 2).

Main outcome measures: Plasma and urine or dialysate samples were analyzed for garenoxacin, and single-dose pharmacokinetic parameters were estimated. Safety was assessed.

Results: Twenty-five subjects received garenoxacin. Compared with healthy controls, garenoxacin area under the concentration–time curve (AUC) and maximum plasma concentration were increased by 51% and lowered by 20%, respectively, in subjects with severe renal impairment. The terminal half-life was prolonged in subjects with severe renal impairment compared with healthy controls (26.5 ± 7?h vs 14.4 ± 3?h, respectively). In subjects receiving HD or CAPD, removal of garenoxacin from systemic circulation was relatively inefficient (HD, 1.5–11.5%; CAPD, 3%), suggesting no need for a supplemental dose of garenoxacin after dialysis. Garenoxacin was well tolerated.

Conclusions: Based on the broad therapeutic index of garenoxacin, the effects of renal impairment on garenoxacin exposure are not considered clinically significant. There was a modest increase in AUC in subjects with severe renal impairment and the magnitude of the changes was not considered clinically relevant.     

Population pharmacokinetics of nefopam in elderly,with or without renal impairment,and its link to treatment response

Aims

Nefopam is a nonmorphinic central analgesic, for which no recommendation exists concerning adaptation of regimen in aged patients with or without renal impairment. The objective was to describe the pharmacology of nefopam in aged patients to obtain guidelines for practical use.

Methods

Elderly patients (n = 48), 65–99 years old, with severe or moderate renal impairment or with normal renal function, were recruited. Nefopam (20 mg) was administered as a 30 min infusion postoperatively. Simultaneously, a 1 min intravenous infusion of iohexol was performed, in order to calculate the glomerular filtration rate. Blood samples were drawn to determine nefopam, desmethyl-nefopam and iohexol plasma concentrations. Nefopam and desmethyl-nefopam concentrations were analysed using a nonlinear mixed-effects modelling approach with Monolix version 4.1.3. The association between pharmacokinetic parameters and treatment response was assessed using logistic regression.

Results

A two-compartment open model was selected to describe the pharmacokinetics of nefopam. The typical population estimates (between-subject variability) for clearance, volume of distribution, intercompartmental clearance and peripheral volume were, respectively, 17.3 l h⁻¹ (53.2%), 114 l (121%), 80.7 l h⁻¹ (79%) and 208 l (63.6%). Morphine requirement was related to exposure of nefopam. Tachycardia and postoperative nausea and vomiting were best associated with maximal concentration and the rate of increase in nefopam plasma concentration.

Conclusions

We identified the nefopam pharmacokinetic predictors for morphine requirement and side-effects, such as tachycardia and postoperative nausea and vomiting. In order to maintain morphine sparing and decrease side-effects following a single dose of nefopam (20 mg), simulations suggest an infusion time of >45 min in elderly patients with or without renal impairment.     

Pharmacokinetics and pharmacodynamics of ranitidine in renal impairment

Objective: The pharmacodynamics and pharmacokinetics of ranitidine were examined in subjects with varying degrees of renal function to determine the effect of this condition on acid-antisecretory activity. Methods: Subjects with creatinine clearances (C_Cr) ranging from 0 to 213 ml · min⁻¹ received single 50-mg and 25-mg i.v. doses of ranitidine. This was followed by determination of serum and urine ranitidine concentrations, and continuous gastric pH monitoring for 24 h. Results: Serum ranitidine concentrations were described by a two-compartment model linked to a sigmoidal E_max model describing gastric pH. Ranitidine renal clearance, ranging from 0 to 1003 ml · min⁻¹, correlated with C_PAH (r ² = 0.707), while non-renal clearance was unaltered. Steady-state volume of distribution decreased by half in severe renal impairment. No changes in the effective concentration at half-maximal response (EC₅₀), maximal response (E_max), or basal response (E₀) were observed. Thus, renal elimination of ranitidine declined in parallel with renal function, while sensitivity to the pharmacologic effect (gastric pH elevation) was unaltered. Ranitidine was well tolerated in these renally impaired subjects. Conclusion: These data indicate that the current recommendation for renal impairment dose reduction (by two-thirds when C_Cr<50 ml · min⁻¹) might result in under-treating moderately impaired patients, and suggests a less conservative dose reduction (by half when C_Cr<10 ml · min⁻¹) to avoid therapeutic failure while remaining within the wide margin of safety for this drug. Received: 10 September 1996 / Accepted in revised form: 7 December 1996     

Steady-state pharmacokinetics of nefazodone in subjects with normal and impaired renal function

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, CL_CR72 ml·min^–1·1.73 m^–2, 6 with moderate (MOD) renal impairment, CL_CR 31–60 ml·min^–1·1.73 m^–2 and 9 with severe (SEV) renal impairment, CL_CR30 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 (C_min) 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 C_max within 2 h after administration of nefazodone; t_max 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 C_max, and elimination t_1/2 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.     

Single-dose pharmacokinetics of nefazodone in healthy young and elderly subjects and in subjects with renal or hepatic impairment

The single-dose pharmacokinetics of nefazodone (NEF) and its metabolites hydroxynefazodone (HO-NEF) and m-chlorophenylpiperazine (mCPP) were examined in 12 healthy younger subjects 55 years of age (YNG), 12 elderly subjects 65 years of age (ELD), 12 patients with biopsy proven hepatic cirrhosis (HEP) and 12 patients with moderate renal impairment (REN), Cl_CR 20–60 ml·min^–1. The study was of parallel group design, with each of the four subject groups receiving escalating single oral doses of 50, 100 and 200 mg of nefazodone at 1 week intervals. Serial blood samples for pharmacokinetic analysis were collected for 48 h following each dose and plasma samples were assayed for NEF, HO-NEF and mCPP by a validated HPLC method.Single oral doses up to 200 mg of nefazodone were well tolerated by all subjects. Maximum plasma levels of NEF and HO-NEF were generally attained within 1 h after administration of nefazodone. HO-NEF and mCPP plasma levels were about 1/3 and <1/10 those of NEF, respectively. There were no apparent gender-related pharmacokinetic differences in any group of subjects. NEF and HO-NEF pharmacokinetics were dose dependent in all four subject groups; a superproportional increase in AUC and an increase in t_1/2 with increasing dose was obtained, indicative of nonlinear pharmacokinetics. Relative to normal subjects, elderly and cirrhotic subjects exhibited increased systemic exposure to NEF and HO-NEF, as reflected by AUC, at all doses of nefazodone; subjects with moderate renal impairment did not.Elderly and cirrhotic patients may require lower doses of NEF to achieve and maintain therapeutic effectiveness.     

Effect of severe renal impairment on the pharmacokinetics of azimilide following single dose oral administration

AIMS: To assess the influence of severe renal impairment on azimilide pharmacokinetics. METHODS: A single oral dose of 125 mg azimilide dihydrochloride was administered to subjects with normal and severely impaired renal function. Blood and urine samples were collected for 22-28 and 10 days, respectively. RESULTS: Azimilide renal clearance decreased in subjects with renal impairment (mean 14 vs 4.8 ml h-1 kg-1, 95% confidence interval on the ratio 0.23, 0.50). However, no change in any other pharmacokinetic parameter including oral clearance (mean 109 vs 104 ml h-1 kg-1, 95% confidence interval on the ratio 0.67, 1.36) was observed. CONCLUSIONS: Since azimilide blood concentrations are essentially unaffected by renal function, an a priori dosage regimen adjustment is not required in patients with renal impairment.     

The effect of renal impairment on the pharmacokinetics of oxcarbazepine and its metabolites

We have studied the effect of renal impairment on the pharmacokinetics of oxcarbazepine, its active monohydroxy-metabolite (which predominates in plasma), their glucuronides, and the inactive dihydroxy-metabolite after a single oral dose of oxcarbazepine (300 mg). Six subjects with normal renal function and 20 patients with various degrees of renal impairment participated.The mean areas under the plasma concentration-time curves of oxcarbazepine and its monohydroxy-metabolite were 2–2.5-times higher in patients with severe renal impairment (CL_CR<10 ml·min^–1) than in healthy subjects. The apparent elimination half-life of the monohydroxy-metabolite [19 (SD 3) h] in these patients was about twice that in healthy subjects.The effect of renal impairment on the plasma concentrations of glucuronides was more marked. The renal clearances of the unconjugated monohydroxy-metabolite and its glucuronides (the main compounds recovered in urine) correlated well with creatinine clearance.The maximum target dose in patients with slight renal impairment (CL_CR>30 ml·min^–1) should not be changed. In patients with moderate renal impairment (CL_CR10–30 ml·min^–1) it should be reduced by 50%. In patients with severe renal impairment (CL_CR<10 ml·min^–1), the glucuronides of oxcarbazepine and its monohydroxy-metabolite are likely to accumulate during repeated administration, and dosage adjustment of oxcarbazepine in these patients could not be proposed from this single administration study.     

Effect of renal impairment on the pharmacokinetics of exenatide

AIMS: To evaluate the pharmacokinetics (PK), safety and tolerability of a single exenatide dose in patients with renal impairment (RI). METHODS: Exenatide (5 or 10 microg) was injected subcutaneously in 31 subjects (one with Type 2 diabetes) stratified by renal function [Cockcroft-Gault creatinine clearance (CrCL), number of subjects]: normal (>80 ml min(-1), n = 8), mild RI (51-80 ml min(-1), n = 8), moderate RI (31-50 ml min(-1), n = 7) or end-stage renal disease (ESRD) requiring haemodialysis (n = 8). PK data were combined with four previous single-dose studies in patients with Type 2 diabetes to explore the relationship of exenatide clearance (CLp/F) and CrCL. RESULTS: Mean half-life for healthy, mild RI, moderate RI and ESRD groups were 1.5, 2.1, 3.2 and 6.0 h, respectively. After combining data from multiple studies, least squares geometric means for CLp/F in subjects with normal renal function, mild RI, moderate RI and ESRD were 8.14, 5.19, 7.11 and 1.3 l h(-1), respectively. Exenatide was generally well tolerated in the mild and moderate RI groups, but not in subjects with ESRD due to nausea and vomiting. Simulations of exenatide plasma concentrations also suggest patients with ESRD should have a propensity for poor tolerability at the lowest available therapeutic dosage (5 microg q.d.). CONCLUSIONS: Since tolerability and PK changes were considered clinically acceptable in patients with mild to moderate RI, it would be appropriate to administer exenatide to these patients without dosage adjustment. However, poor tolerability and significant changes in PK make the currently available therapeutic doses (5 and 10 microg) unsuitable in severe RI or ESRD.     

Population pharmacokinetics of doxorubicin in Indian cancer patients using NONMEM

The population pharmacokinetics of doxorubicin were evaluated based on a mixed-effect model using the NONMEM (VI) program. Doxorubicin in plasma was measured using high-performance liquid chromatography. Plasma concentration measurements (85 plasma samples) of doxorubicin from 28 patients with cancer receiving doxorubicin (with other co-medication) ranging from 20–120?mg by infusion over 1–2?h were analyzed according to a two-compartment model both in FO and FOCE methods. Additive proportional error model was used to describe inter-individual and residual variability. The influence of covariates such as age, body surface area, gender, and clinical laboratory values (SGOT, SGPT) on total body clearance (CL) and volume of distribution (Vd) were examined. No covariate was found to affect the CL and Vd of unchanged doxorubicin. The CL and Vd estimated by FO method were 1.42?L/h and 51.1?L, respectively, and FOCE method are 1.43?L/h and 51.4?L, respectively. The inter-individual variability for CL and Vd and residual variability were 45.8%, 36%, and 12.6%, respectively. The population means and inter-individual and residual variability of pharmacokinetics of doxorubicin were evaluated using the NONMEM program. The results of this study show that the population pharmacokinetic approach could be useful to manage doxorubicin cardio toxicity using sparse data in a clinical setting.     

Effects of renal impairment on the pharmacokinetics, pharmacodynamics and safety of rivaroxaban, an oral, direct Factor Xa inhibitor

AIM

This study evaluated the effects of impaired renal function on the pharmacokinetics, pharmacodynamics and safety of rivaroxaban (10 mg single dose), an oral, direct Factor Xa inhibitor.

METHODS

Subjects (n= 32) were stratified based on measured creatinine clearance: healthy controls (≥80 ml min⁻¹), mild (50–79 ml min⁻¹), moderate (30–49 ml min⁻¹) and severe impairment (<30 ml min⁻¹).

RESULTS

Renal clearance of rivaroxaban decreased with increasing renal impairment. Thus, plasma concentrations increased and area under the plasma concentration–time curve (AUC) LS-mean values were 1.44-fold (90% confidence interval [CI] 1.1, 1.9; mild), 1.52-fold (90% CI 1.2, 2.0; moderate) and 1.64-fold (90% CI 1.2, 2.2; severe impairment) higher than in healthy controls. Corresponding values for the LS-mean of the AUC for prolongation of prothrombin time were 1.33-fold (90% CI 0.92, 1.92; mild), 2.16-fold (90% CI 1.51, 3.10 moderate) and 2.44-fold (90% CI 1.70, 3.49 severe) higher than in healthy subjects, respectively. Likewise, the LS-mean of the AUC for Factor Xa inhibition in subjects with mild renal impairment was 1.50-fold (90% CI 1.07, 2.10) higher than in healthy subjects. In subjects with moderate and severe renal impairment, the increase was 1.86-fold (90% CI 1.34, 2.59) and 2.0-fold (90% CI 1.44, 2.78) higher than in healthy subjects, respectively.

CONCLUSIONS

Rivaroxaban clearance is decreased with increasing renal impairment, leading to increased plasma exposure and pharmacodynamic effects, as expected for a partially renally excreted drug. However, the influence of renal function on rivaroxaban clearance was moderate, even in subjects with severe renal impairment.     

Population pharmacokinetics of domperidone in preterm neonates

Purpose  A population pharmacokinetic analysis was performed to define domperidone pharmacokinetic parameters in preterm neonates, as no pharmacokinetic data are available in this population. Methods  An oral domperidone solution was administered (0.75 mg/kg per day) in 32 preterm neonates (64 samples). Domperidone plasma concentration was measured by high-performance liquid chromatography (HPLC) assay, and a one-compartment model with first-order absorption was fitted to the data using NONMEM version V level 1.1. Results  The mean peak and trough plasma concentration values of domperidone were, respectively, 25.3 ± 20.5 ng/ml and 15.4 ± 11.4 ng/ml (mean ± standard deviation). The pharmacokinetic parameters (interindividual variability%) were clearance (Cl/F) = 0.92 L/h (51.6%), volume of distribution (Vd/F) = 0.405 L (68%), and absorption constant rate (Ka) = 0.0843 h⁻¹ (55.8%). The clearance is not lower than values reported in adults. No influence of covariates (postnatal age, prematurity, weight, gender) on domperidone pharmacokinetic parameters was found. Conclusion  This pilot study designed with a limited sampling strategy showed that domperidone plasma concentrations were consistent with those reported in adults, suggesting that domperidone dosage regimen currently used in preterm neonates is suitable.     

Population pharmacokinetics of arbekacin in burn patients

The aim of this study was to estimate the pharmacokinetics (PK) of arbekacin in burn patients using a population–PK approach. Therapeutic drug monitoring data consisting of 126 plasma concentrations (including 17 values that were below the quantitation limit) from 47 burn patients were retrospectively analyzed using a mixed effect method (NONMEM, ver. 6.0). Covariates, such as burn index, age, sex, among others, were tested on the basic one-compartment model. In the basic model, positive correlations of body weight (WT) and creatinine clearance (CLcr) on total clearance (CL) and volume of distributions (V) were assumed. In the final model, V increased with burn index (BI). The final model was: ;. Between-subject variability in terms of CL and V were 35 and 39%, respectively. The CL of our burn patients was significantly greater than that reported in unburned patients, and V increased proportionally with increasing BI.     

The pharmacokinetics and safety of darapladib in subjects with severe renal impairment

Aim

Darapladib is a potent and reversible orally active inhibitor of lipoprotein-associated phospholipase A₂ (Lp-PLA₂). The aim of the study was to assess the effects of severe renal impairment on the pharmacokinetics and safety/tolerability of darapladib compared with normal renal function.

Methods

This was an open label, parallel group study of darapladib following 10 day once daily 160 mg oral dosing in subjects with normal (n = 8) and severe renal impairment (estimated glomerular filtration rate <30 ml min^–1 1.73 m^–2, n = 8). Plasma concentrations of total and unbound darapladib as well as total darapladib metabolites were determined in samples obtained over 24 h on day 10.

Results

Plasma concentrations of total and unbound darapladib as well as all three metabolites were higher in subjects with severe renal impairment. Area under the plasma concentration vs. time curve between time zero and 24 h (AUC(0,24 h) and maximum plasma concentration (C_max) of total darapladib in severely renally impaired subjects were 52% and 59% higher than those in the matched healthy subjects, respectively. Similar results were found with the darapladib metabolites. Darapladib was highly plasma protein bound with 0.047% and 0.034% unbound circulating in plasma in severely renally impaired and healthy subjects, respectively. Unbound plasma darapladib exposures were more than two-fold higher in severely renally impaired subjects than in healthy controls. Adverse events (AE) were reported in 38% of healthy subjects and 75% of severely renally impaired subjects, most of which were mild or moderate in intensity.

Conclusions

The results of this study showed that darapladib exposure was increased in subjects with severe renal impairment compared with healthy controls. However, darapladib was generally well tolerated in both groups.     

Nimesulide and renal impairment

Objectives: To analyse from spontaneous reporting data the renal adverse reactions associated with the use of nimesulide. Methods: Case reports were obtained from a Northern Italian Regional database (Veneto Pharmacovigilance System), containing all the spontaneous reports filed between 1988 and 1997. The Veneto Region is the principal contributor to the Italian spontaneous reporting system, with an annual report rate of approximately 17 per 100 000 inhabitants. The clinical records of hospitalized patients were also analysed. Results: Of the 120 reports associated with oral nimesulide, 11 referred to suspected renal adverse reactions. The drug was taken by ten patients for a short period. All the patients discontinued the therapy and hospitalization was required in six cases. Other risk factors were identified in six cases. Discussion: Together with the new insights into the possible consequences of renal cyclooxygenase-2 (COX-2) inhibition, the reported cases should draw the attention of doctors and patients to the importance of recognizing any possible signs of renal impairment during nimesulide therapy, although only extensive epidemiological data can define the real impact of its renal toxicity. Received: 27 July 1998/ Accepted in revised form: 23 November 1998     

Single-dose pharmacokinetics of paracetamol and its conjugates in Chinese non-insulin-dependent diabetic patients with renal impairment

Objective: A single oral dose of paracetamol (20 mg · kg⁻¹) was given to 38 Chinese patients with non-insulin-dependent diabetes mellitus (NIDDM) who had either normal renal function or varying degrees of renal impairment, with creatinine clearances ranging from 4 to 123 ml · min⁻¹ · 1.73 m⁻². The plasma and urinary concentrations of paracetamol and its major metabolites were measured by high-performance liquid chromatography (HPLC). Results: The absorption and elimination of paracetamol were unaffected by renal impairment. However, the area under the plasma concentration time curve and the elimination half-life of paracetamol metabolites increased significantly with worsening renal insufficiency. Mean renal clearances of paracetamol and its conjugates were significantly reduced in these subjects. There was no evidence of altered metabolic activation with renal impairment. Conclusion: The results demonstrate that paracetamol disposition is minimally affected by diabetic nephropathy; however, extensive accumulation of conjugates may occur. Received: 2 September 1996 / Accepted in revised form: 11 December 1996