The effect of paroxetine on the pharmacokinetics,safety, and tolerability of ramosetron in healthy subjects

Objective The aim of our study was to investigate the effects of multiple doses of paroxetine on the pharmacokinetics, safety, and tolerability of a single oral 10-μg dose of ramosetron. Methods This was an open, one-sequence crossover design study. On day 1, healthy male and female subjects were administered a single dose of 10 μg ramosetron. On the morning of day 3, the subjects were administered paroxetine to reach steady state, which consisted of morning doses of 20 mg on days 3–12. The dose on day 11 was administered in combination with a single dose of 10 μg ramosetron. Results In subjects genotyped as extensive CYP2D6 metabolizers, coadministration of paroxetine with ramosetron resulted in an increase in area under the curve from 0 to infinity (AUC_0-inf) and the peak concentration (C_max) of ramosetron by 1.14-fold (90% confidence interval (CI): 1.07–1.22) and by 1.06-fold (90% CI: 1.00–1.11), respectively. Conclusions It can be concluded that the single-dose pharmacokinetic profile of ramosetron 10 μg is not affected to a clinically relevant degree by paroxetine 20 mg once daily administered for 10 days.     

Effects of dosage and CYP2D6-mutated allele on plasma concentration of paroxetine

Objective We investigated the effect of dosages of paroxetine and cytochrome P450 (CYP) 2D6 genotypes on the plasma concentration of paroxetine in Japanese patients being treated with paroxetine.Methods Blood samples were collected from 73 individuals after at least 2 weeks of the same daily dose of paroxetine. The plasma paroxetine concentration was measured using HPLC, and the CYP2D6 genotypes were identified by PCR. Genotype groups were compared by one-way analysis of variance at different paroxetine doses.Results The mean plasma paroxetine concentrations at daily doses of 10, 20, 30, and 40 ng/ml were 6.6±7.4, 34.9±26.8, 74.8±37.2, and 130.5±96.8 ng/ml, respectively, showing a disproportionate and nonlinear increase in plasma drug levels of paroxetine upon increasing doses. Plasma paroxetine concentrations in patients with CYP2D6*10 alleles were significantly higher than those without *10 allele at 10 mg/day (7.3±6.11 vs. 2.99±3.52 ng/ml), but there was no significant difference between *1/*1, *1/*10 and *10/*10 genotypes at the higher doses. Similarly, patients with CYP2D6*5 alleles showed higher plasma paroxetine concentrations than those without *5 allele, although differences in the plasma paroxetine concentration did not reach statistical significance level because of the small number of subjects with *5 alleles.Conclusions Our results indicate the possibility of saturation in paroxetine metabolism with an increase in paroxetine dose, and that CYP2D6*10 allele(s) have significant impact on plasma paroxetine concentration at low doses in Japanese population.     

Atomoxetine pharmacokinetics in healthy Chinese subjects and effect of the CYP2D6*10 allele

AIMS: To characterize atomoxetine pharmacokinetics, explore the effect of the homozygous CYP2D6*10 genotype on atomoxetine pharmacokinetics and evaluate the tolerability of atomoxetine, in healthy Chinese subjects. METHODS: Twenty-four subjects, all CYP2D6 extensive metabolizers (EM), were randomized to receive atomoxetine (40 mg qd for 3 days, then 80 mg qd for 7 days) or matching placebo (2 : 1 ratio) in a double-blind fashion. Atomoxetine serum concentrations were measured following single (40 mg) and multiple (80 mg) doses. Adverse events, clinical safety laboratory data and vital signs were assessed during the study. RESULTS: Atomoxetine was rapidly absorbed with median time to maximum serum concentrations of approximately 1.5 h after single and multiple doses. Atomoxetine concentrations appeared to decrease monoexponentially with a mean apparent terminal half-life (t(1/2)) of approximately 4 h. The apparent clearance, apparent volume of distribution and t(1/2) following single and multiple doses were similar, suggesting linear pharmacokinetics with respect to time. Homozygous CYP2D6*10 subjects had 50% lower clearances compared with other EM subjects, resulting in twofold higher mean exposures. No clinically significant changes or abnormalities were noted in laboratory data and vital signs. CONCLUSIONS: The pharmacokinetics of atomoxetine in healthy Chinese subjects appears comparable to other ethnic populations. Multiple dosing of 80 mg qd atomoxetine was well tolerated in this study.     

Haloperidol plasma concentration in Japanese psychiatric subjects with gene duplication of CYP2D6

AIMS: The cytochrome P-450 2D6 (CYP2D6) gene duplication/multiduplication producing an increase in enzyme activity, and the common Japanese mutation, CYP2D6*10A producing a decrease of enzyme activity were screened in a large number of Japanese psychiatric subjects (n = 111) in order to investigate whether these mutated alleles affected the plasma concentration of haloperidol. METHODS: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was performed to identify the CYP2D6*10A and CYP2D6*2 genotypes in subjects who had been taking haloperidol. For the screening of duplicated active CYP2D6 gene, allele-specific long PCR was performed. Plasma concentration of haloperidol was measured by the enzyme immunoassay, and expressed as "plasma concentration dose ratio" to normalize individual differences. RESULTS: The plasma concentration-dose ratio showed large interindividual differences of approximately 18-fold. PCR-RFLP methods revealed that 29 (26.1%), 10 (9.0%), 39 (35.1%), 0 (0%), seven (6.3%) and 26 (23.4%) cases possessed the CYP2D6 genotypes *1/*1, *1/*2, *1/*10A, *2/*2, *2/*10A and *10 A/*10A, respectively. Six cases (5.4%) had duplicated CYP2D6 genes. There were no significant differences of plasma concentration-dose ratio between the groups classified by CYP2D6*10A and *2 genotypes (Kruskal-Wallis test; P = 0.37), even in those cases whose daily doses were lower than 20 mg (n = 90, P = 0.91). Subjects having duplicated genes (n = 6) did not show significant differences of plasma concentration-dose ratio by comparison with subjects who had no duplicated genes (Mann-Whitney U-test; P = 0.80). CONCLUSIONS: Gene duplication, and the common Japanese mutation CYP2D6*10A on CYP2D6 gene are not likely to be the main modulatory factors of plasma concentration of haloperidol in Japanese psychiatric subjects.     

RP-HPLC法测定人血浆中帕罗西汀的浓度

目的 建立测定人血浆中帕罗西汀浓度的反相高效液相色谱法.方法 以DiamonsilTMC18反相柱(150 mm×4.6 mm,5μm)为色谱柱,流动相为0.03mol·L-1醋酸铵-甲醇(33∶67);流速:0.8mL·min-1;柱温:40℃;检测波长:290nm.以乙酸乙酯与二氯甲烷(80∶20)为提取剂.结果 帕罗西汀的高、中、低(1000.0,400.0,10.0ng·mL-1)3种浓度平均回收率分别为104.28%、97.60%、98.40%,日内、日间差RSD均低于7%(n=5);分析方法的检测限为5.0μg·L-1;线性范围为10.0～1000.0μg·L-1.回归方程为:C=15.29F-1.21,r=0.9993(n=10).结论 该方法灵敏、准确、简单、快速,可用于临床血药学临床和药动学研究.     

EEG and blood level of the potential antidepressant paroxetine after a single oral dose to normal volunteers

The quantitative electroencephalogram (EEG) and plasma concentration of the antidepressant paroxetine were monitored in five normal volunteers after a single oral dose of 70 mg paroxetine and placebo. Peak plasma concentration occurred 4–6 h post-dose. Placebo had little effect on the EEG but the effects of paroxetine were statistically significant at 6 h post-dose. The EEG changes after treatment consisted of a decrease in delta and theta activity (< 8 Hz) and increase in beta activity (>12 Hz). These changes were still evident 72 h after treatment. The EEG profile obtained with 70 mg paroxetine is similar to that reported for other antidepressant 5-HT uptake inhibitors, but dissimilar to the classical, sedative antidepressants.     

Inhibition of metoprolol metabolism and potentiation of its effects by paroxetine in routinely treated patients with acute myocardial infarction (AMI)

Objective To investigate the influence of paroxetine on metoprolol concentrations and its effect in patients treated for acute myocardial infarction (AMI) who are routinely given paroxetine as a co-treatment of depression. Methods We recruited 17 depressed AMI patients who received metoprolol as a routine part of their therapy (mean dose 75 ± 39 mg/day). Patients were genotyped for CYP2D6 *3, *4 and gene duplication. Metoprolol and α-hydroxy-metoprolol were analyzed in plasma 0, 2, 6 and 12 h post-dose. Heart rates (HR) at rest were registered after each sampling. Paroxetine 20 mg daily was then administered, and all measurements were repeated on day 8. Results All patients were genotypically extensive metabolizers (EMs) (nine with *1/*1 and eight with *1/*3 or *4). Following the administration of paroxetine, mean metoprolol areas under the concentration–time curve (AUC) increased (1064 ± 1213 to 4476 ± 2821 nM × h/mg per kg, P = 0.0001), while metabolite AUCs decreased (1492 ± 872 to 348 ± 279 n M × h/mg per kg, P < 0.0001), with an increase of metabolic ratios (MR) (0.9 ± 1.3 to 26 ± 29; P < 0.0001). Mean HRs were significantly lower after the study week at each time point. Mean area under the HR versus time curve (AUEC) decreased (835 ± 88 to 728 ± 84 beats × h/min; P = 0.0007). Metoprolol AUCs correlated with patients’ AUECs at the baseline (Spearman r  = −0.64, P < 0.01), but not on the eighth day of the study. A reduction of metoprolol dose was required in two patients due to excessive bradycardia and severe orthostatic hypotension. No other adverse effects of the drugs were identified. Conclusion A pronounced inhibition of metoprolol metabolism by paroxetine was observed in AMI patients, but without serious adverse effects. We suggest, however, that the metoprolol dose is controlled upon initiation and withdrawal of paroxetine.     

Famotidine increases plasma alcohol concentration in healthy subjects

The effect of famotidine on plasma alcohol concentration was studied in 24 healthy male subjects who demonstrated high apparent ethanol first-pass metabolism after oral (p.o.) and intravenous (i.v.) ethanol administration (i.e. AUC_po S 40% of AUC_iv, where AUC is area under the plasma ethanol concentration-time curve). Six of the original 30 subjects screened (20%) did not demonstrate high first-pass metabolism and were excluded. In a randomized open crossover study, oral ethanol pharmacokinetics were assessed after breakfast in the morning following a 3-day regimen of famotidine, 40 mg/day, and following a no-drug control period. Famotidine increased the area under the plasma ethanol concentration-time curve (AUC_0-t) by 29% (7.1 vs 5.5 mg.h/dL, P= 0.006) and maximal plasma concentration (C_max) by 23% (9.2 vs 7.5 mg/dL, P= 0.013). The changes in ethanol AUC_0-t and C_max may have been associated with changes in gastric emptying, as they were inversely correlated with changes in the time at which maximal plasma concentration was attained. There was considerable intra-individual variation in ethanol AUC and C_max. As a result, regression to the mean is a potentially confounding problem in ethanol pharmacokinetic studies when subjects are selected on the basis of having low AUC_po, and properly controlled randomized studies of substantial size are required to detect modest drug effects. Small effects on ethanol pharmacokinetics have now been demonstrated with all four of the major H₂-receptor antagonists, but these effects are seen only under specific experimental conditions and appear to be unimportant clinically.     

The effect of cimetidine or omeprazole on the pharmacokinetics of escitalopram in healthy subjects

AIMS: To investigate the effects of co-administration of cimetidine or omeprazole on the pharmacokinetics of escitalopram. METHODS: Two randomized placebo-controlled crossover studies were carried out. Sixteen healthy subjects were administered placebo, or cimetidine (400 mg twice daily) for 5 days (study 1) or omeprazole (30 mg once daily) for 6 days (study 2). On day 4 (study 1) or day 5 (study 2), a single dose of escitalopram (20 mg) was administered. Blood samples were taken at predetermined times for the measurement of serum concentrations of escitalopram and its demethylated metabolite (S-DCT). Treatment-emergent adverse events were also monitored. RESULTS: Co-administration with cimetidine caused a moderate increase in the systemic exposure [AUC0, infinity] to escitalopram (geometric mean ratio = 1.72, [95% CI 1.34, 2.21]) and a small increase in t(1/2) from 23.7 to 29.0 h (5.24 h [3.75, 6.70]). Co-administration with omeprazole also resulted in a moderate increase in the escitalopram AUC(0, infinity) (1.51 [1.39, 1.64]) and a small increase in t(1/2) from 26.5 to 34.8 h (8.3 h [6.44, 10.2]). There was no significant change in S-DCT AUC0, infinity after co-administration of either cimetidine or omeprazole. Co-administration of cimetidine or omeprazole had no effect on the incidence of treatment-emergent adverse events. CONCLUSIONS: In view of the good tolerability of escitalopram, the pharmacokinetic changes observed on co-administration with cimetidine or omeprazole are unlikely to be of clinical concern.     

The CYP2C8 inhibitor trimethoprim increases the plasma concentrations of repaglinide in healthy subjects

AIMS: Our aim was to investigate the effect of the CYP2C8 inhibitor trimethoprim on the pharmacokinetics and pharmacodynamics of the antidiabetic drug repaglinide, and to examine the influence of the former on the metabolism of the latter in vitro. METHODS: In a randomized, double-blind, crossover study with two phases, nine healthy volunteers took 160 mg trimethoprim or placebo orally twice daily for 3 days. On day 3, 1 h after the last dose of trimethoprim or placebo, they ingested a single 0.25 mg dose of repaglinide. Plasma repaglinide and blood glucose concentrations were measured for up to 7 h post-dose. In addition, the effect of trimethoprim on the metabolism of repaglinide by human liver microsomes was investigated. RESULTS: Trimethoprim raised the AUC(0, infinity ) and C(max) of repaglinide by 61% (range, 30-117%; P= 0.0008) and 41% (P = 0.005), respectively, and prolonged the t((1/2)) of repaglinide from 0.9 to 1.1 h (P = 0.001). Trimethoprim had no significant effect on the pharmacokinetics of its aromatic amine metabolite (M1), but decreased the M1 : repaglinide AUC(0, infinity ) ratio by 38% (P = 0.0005). No effect of trimethoprim on the blood glucose-lowering effect of repaglinide was detectable. In vitro, trimethoprim inhibited the metabolism of (220 nm) repaglinide in a concentration-dependent manner. CONCLUSIONS: Trimethoprim raised the plasma concentrations of repaglinide probably by inhibiting its CYP2C8-mediated biotransformation. Although the interaction did not significantly enhance the effect of repaglinide on blood glucose concentration at the drug doses used, the possibility of an increased risk of hypoglycaemia should be considered during concomitant use of trimethoprim and repaglinide in patients with diabetes.     

Effect of ketoconazole on the pharmacokinetics of imipramine and desipramine in healthy subjects

Aims The aim of the study was to characterize further the role of CYP3A4 in the metabolism of tricyclic antidepressants.
Methods The effect of oral ketoconazole (200  mg day⁻¹ for 14 days) on the kinetics of a single oral dose of imipramine (100  mg) and desipramine (100  mg) was evaluated in two groups of six healthy male subjects.
Results Ketoconazole administration was associated with a decrease in imipramine apparent oral clearance (from 1.16±0.21 to 0.96±0.20  l h⁻¹  kg⁻¹, mean±s.d.; ' of2\P<0.02), a prolongation in imipramine half-life (from 16.7±3.3 to 19.2±5.4  h, ' of2\P<0.05) and a decrease in area under the curve of metabolically derived desipramine (from 3507±1707 to 3180±1505  nmol  l⁻¹  h, P <0.05), whereas concentrations of 2-hydroxy-imipramine were unaffected. In the subjects given desipramine, no significant changes in desipramine and 2-hydroxy-desipramine kinetics were observed during ketoconazole treatment.
Conclusions These findings indicate that ketoconazole, a relatively specific inhibitor of CYP3A4, inhibits the N -demethylation of imipramine without affecting the 2-hydroxylation of imipramine and desipramine. This interaction, confirms that CYP3A4 plays a role in the demethylation of tricyclic antidepressants.     

Voriconazole drastically increases exposure to oral oxycodone

Objective  We investigated the effect of voriconazole on the pharmacokinetics and pharmacodynamics of oxycodone. Methods  Twelve healthy subjects ingested either voriconazole or placebo for 4 days in a randomized, cross-over study. On day 3, they ingested 10 mg oxycodone. Timed plasma samples were collected for the measurement of oxycodone, noroxycodone, oxymorphone, noroxymorphone and voriconazole up to 48 h, and pharmacodynamic effects were recorded. Results  When voriconazole was taken at the same time as oxycodone, the mean area under the plasma concentration-time curve (AUC_0–∞) of oxycodone increased 3.6-fold (range 2.7- to 5.6-fold), peak plasma concentration 1.7-fold and elimination half-life 2.0-fold (p < 0.001) when compared to placebo. The AUC_0-∞ ratio of noroxycodone to oxycodone was decreased by 92% (p < 0.001), and that of oxymorphone increased by 108% (p < 0.01). Pharmacodynamic effects of oxycodone were modestly increased by voriconazole. Conclusions  Voriconazole inhibits the CYP3A-mediated N-demethylation of oxycodone, drastically increasing exposure to oral oxycodone. Clinically, lower doses of oxycodone may be needed during voriconazole treatment to avoid opioid-related adverse effects especially after repeated dosing.     

普罗帕酮在健康受试者中的药动—药效学结合模型研究

目的:采用药动-药效结合模型观察普罗帕酮血浆浓度与心电图指标PR间期延长百分率的数量关系,并求算药效学参数。方法:选择健康汉族受试者10名,其中CYP2D6表型的快代谢型(EM)和中速代谢型(IM)各5名。受试者口服普罗帕酮片剂400mg,于给药后15h内抽取静脉血,并同步测定受试者PR间期。普罗帕酮浓度采用高效液相色谱分析法测定。采用CAPP软件对普罗帕酮血药浓度及PR间期延长百分率进行药动-药效结合模型计算。结果:10例健康志愿者的普罗帕酮血浆浓度与效应之间存在着滞后现象。经采用CAPP软件拟合数据,发现效应与浓度之间符合Sigmoid E_(max)模型。IM组的AUC(μg·h·L~(-1))明显高于EM组(5126±1030 vs2948±1230,P<0.05);相对应药效参数Ce_(50)IM组也比EM组大(P<0.05)。另外,效应曲线S线程度的参数γEM组大于IM组(P<0.05)。结论:CYP2D6遗传多态性不但对普罗帕酮的药动学有影响,而且对其药效学参数可能也有明显的影响。     

Pharmacokinetics of tenoxicam after oral administration in healthy human subjects of various single doses

Single oral dose pharmacokinetics of tenoxicam in the dose range intended for therapeutic application of the drug have been defined in healthy human subjects. Twelve male volunteers were given, in random fashion, oral administration of 10, 20 or 40 mg of tenoxicam. Plasma drug levels were determined by a standard HPLC method with U.V. detection. Model-independent analysis showed the clearance, elimination half-life and apparent volume of distribution to be independent of dose with mean values of 0.096 L/h, 76 h and 9.2 L respectively. Interindividual variation was six-fold and individual variation less than two-fold. Similar values for kinetic parameters were obtained by model-dependent methods. The pharmacokinetics of oral tenoxicam were linear in the 10-40 mg dose range and the single dose data predict five-fold accumulation for once daily administration.     

Pharmacokinetics of sarizotan after oral administration of single and repeat doses in healthy subjects

OBJECTIVE: Sarizotan is a 5-HTIA receptor agonist with high affinity for D3 and D4 receptors. Here we report the pharmacokinetic and tolerability results from four Phase 1 studies. MATERIALS: Two single-dose (5 -25 mg, n = 25, 0.5 - 5 mg, n = 16) and two multiple-dose (10 and 20 mg b.i.d., n = 30, 5 mg b.i.d., n = 12) studies with orally administered sarizotan HCl were carried out in healthy subjects. METHODS: Plasma sarizotan HCl concentrations were measured using a validated HPLC method and fluorescence or MS/MS detection. Pharmacokinetic parameters were obtained using standard non-compartmental methods. RESULTS: Sarizotan was rapidly absorbed, group-median times to reach maximum concentration (tmax) ranged from 0.5 -2.25 h after single doses and during steady state. Maximum plasma concentration (Cmax) and tmax were slightly dependent on formulation and food intake, whereas area under the curve (AUC) was unaffected by these factors. AUC and Cmax increased dose-proportionally over the tested dose range. Independently of dose and time, sarizotan HCl plasma concentrations declined polyexponentially with a terminal elimination half-life (t1/2) of 5 - 7 h. Accumulation factors corresponded to t1/2 values, and steady state was reached within 24 h. Plasma metabolite concentrations were considerably lower than those of the parent drug. The ratio metabolite AUC : parent drug AUC was time- and dose-independent for all three metabolites suggesting that the metabolism of sarizotan is non-saturable in the tested dose range. CONCLUSIONS: The pharmacokinetics of sarizotan were dose-proportional and time-independent for the dose range 0.5 -25 mg). The drug was well-tolerated by healthy subjects up to a single dose of 20 mg.     

单剂量口服他达拉非在中国健康男性受试者的药代动力学和安全性

目的 研究中国健康男性受试者单剂量口服他达拉非的药代动力学和安 全性。方法 用双盲随机安慰剂对照三交叉设计。在3个周期随机单次服用 他达拉非10,20 mg或安慰剂,采集静脉血,用液相色谱-质谱法测定血药浓度 并计算药代动力学参数。结果 单次服用他达拉非10,20 mg后的主要药代动 力学参数AUC0-t分别为3750和7180 ng·h·mL-1;AUC0-∞分别为3820和 7370 ng·h·mL-1;Cmax分别为172和274 ng·mL-1;tmax分别为3．00和4．00 h;CL／F分别为2．61和2．71 L·h-1;V／F分别为67．6和73．2 L。结论 他达 拉菲在10-20 mg,中国健康男性受试者较安全,且AUC与剂量呈正相关。     

Analysis of sleep EEG microstructure in subchronic paroxetine treatment of healthy subjects

Paroxetine is a selective and potent serotonin reuptake inhibitor and its efficacy for the treatment of depression has been proven. Under acute and subchronical treatment regimens, disturbances of the regular sleep pattern are a reported side effect of the drug. The present study was therefore performed to investigate the impact of subchronic treatment with the selective serotonin reuptake inhibitor paroxetine on the microstructure of the sleep EEG. The study especially addressed the question of subchronic effects of paroxetine medication (30 mg/day) in eight healthy male volunteers in a double blind, placebo-controlled crossover design. Conventional sleep EEG parameters and a spectral power analysis for different sleep stages after 4 weeks of treatment were computed. Additionally, the correlation of certain EEG rhythms across the night was calculated in order to detect subtle dynamical EEG alterations, not necessarily obvious when regarding conventional EEG analysis. Although we could not detect any alterations of the spectral power values in certain frequency bands either during NREM nor during REM sleep following subchronic paroxetine medication, the dynamical EEG attributes across the night revealed a significant enhancement of the correlation between certain EEG rhythms mainly during NREM sleep. Received: 18 July 1996 /Final version: 19 February 1997     

CYP2D6基因多态性对帕罗西汀在中国健康人药动学影响

目的研究中国健康人CYP2D6基因多态性对帕罗西汀药动学的影响。方法使用PCR-RFLP方法将23位志愿者分为3组:CYP2D6*1/*1组(n=5),CYP2D6*1/*10组(n=7),CYP2D6*10/*10组(n=11)。给予帕罗西汀20 mg单剂量口服,收集给药后96 h内的一系列血样,用LC-MS/MS法测定帕罗西汀的血药浓度并做药动学分析。结果与CYP2D6*1/*1组药动学参数相比,CYP2D6*1/*10组t_(max)、t1/2和CYP2D6*10/*10组t_(max)无显著差异(P>0.05);CYP2D6*1/*10、CYP2D6*10/*10组的ρ_(max)、AUC_(0-96 h)、AUC_(0-∞)、CL(F)、Vd和CYP2D6*10/*10组t_(1/2)均有显著差异(P<0.05或P<0.01)。结论 CYP2D6*10等位基因突变能引起代谢表型的改变,影响帕罗西汀在健康人的体内代谢。     

口服后莫达非尼及其代谢产物在汉族健康人体内的药物动力学

目的研究莫达非尼及其代谢产物(莫达非尼酸)在中国汉族健康人体内的药物动力学过程。方法10名健康志愿者口服莫达非尼片200 mg,采用HPLC法测定给药后不同时间点的莫达非尼及其代谢物的浓度,用DSA软件求算其药物动力学参数,并比较药物动力学参数在性别上的差异。结果莫达非尼及其代谢物莫达非尼酸的药物动力学过程符合二室模型拟合,其药物动力学参数分别为:莫达非尼tmax(1.69±0.70)h,ρmax(4.14±1.21)mg.L-1,AUC0-∞(65.96±11.69)mg.h.L-1;莫达非尼酸tmax(3.06±0.94)h,ρmax(3.19±0.95)mg.L-1,AUC0-∞(45.94±13.44)mg.h.L-1。结论口服莫达非尼在人体内其原形及代谢产物药物动力学均符合二室模型拟合,其药物动力学参数没有性别差异。     

Pharmacokinetics of eltoprazine in healthy male subjects after single dose oral and intravenous administration.

The kinetics, safety and tolerability of eltoprazine hydrochloride were studied in an open, cross-over, partially randomised design after single oral (8 mg) and intravenous (3 and 8 mg) doses to 12 healthy male subjects. After intravenous administration, the mean t1/2 ranged from 7 to 9 h, the MRT was 11 h, CL was 487 +/- 148 (3 mg dose) and 471 +/- 56 (8 mg dose) ml kg-1 h-1, while CLR was 226 +/- 124 (3 mg dose) and 189 +/- 38 (8 mg dose) ml kg-1 h-1. The Vss was 3.3 +/- 0.7 (3 mg dose) and 3.8 +/- 0.5 (8 mg dose) 1 kg-1. Cumulative renal excretion was 40%. The AUC and the cumulative urinary excretion were directly proportional to dose within the range of 3-8 mg. Values of tmax varied from 1 to 4 h after oral administration. The mean Cmax value was 24 ng ml-1 after an oral dose of 8 mg. The plasma elimination half-life after oral administration was 9.8 +/- 3.9 h. Absolute oral bioavailability was 110 +/- 32%. Dose-dependent somnolence was observed.