Pharmacokinetics and safety of viramidine, a prodrug of ribavirin, in healthy volunteers

Ribavirin, part of the current first-line combination therapy for the treatment of chronic hepatitis C, has side effects-in particular, hemolytic anemia-that is frequently dose limiting. Based on animal studies, viramidine, a prodrug of ribavirin, is converted to ribavirin in the liver. Viramidine dosing yielded 50% higher ribavirin levels in the monkey liver but only half in plasma and red blood cells compared to ribavirin dosing. At the same dose, it also had a safer profile than ribavirin in a 28-day toxicity study in monkeys. The current study was carried out to evaluate the safety, tolerability, and pharmacokinetics of viramidine in healthy male volunteers (n = 8-18 on viramidine vs. 2 on placebo at each dose level) after oral dosing of viramidine at 200, 600, and 1200 mg. There were no serious adverse events, and most adverse events were mild. The percentages of treatment-emergent events judged to be possibly related to the study drug were 50% in the 1200-mg group, 26% in the 600-mg group, and none in the 200-mg group. Viramidine was orally absorbed and rapidly converted to ribavirin with a t(max) of 1.5 to 3.0 hours for both viramidine and ribavirin in plasma. There was dose proportionality in plasma AUC(0-168 h) and C(max) for viramidine and in plasma AUC(0-168 h) for ribavirin. Plasma AUC(0-168 h) for ribavirin was two to four times higher than plasma AUC(0-168 h) for viramidine, indicating that viramidine is extensively metabolized to ribavirin and is a prodrug of ribavirin in man. Amounts of viramidine and ribavirin excreted in the urine were small (2%-5% of dose), indicating that the main route of elimination for both viramidine and ribavirin is metabolism. Both viramidine and ribavirin were excreted into urine through the mechanism of glomerular filtration. In addition, an evaluation of the effect of a high-fat meal on the pharmacokinetics of viramidine and ribavirin after oral dosing of viramidine at 600 mg was conducted in healthy male volunteers (n = 33-34) in a crossover study design. A high-fat meal increased viramidine plasma AUC(0-168 h) by 44% and C(max) by 20%. It also increased ribavirin plasma AUC(0-168 h) by 19% and C(max) by 43%. The clinical relevance of these increases is unknown.     

A double-blind, placebo-controlled study to assess tolerability, pharmacokinetics and preliminary pharmacodynamics of single escalating doses of Z13752A, a novel dual inhibitor of the metalloproteases ACE and NEP, in healthy volunteers

AIMS: The objective of this study was to evaluate the tolerability of a novel dual ACE-NEP inhibitor, Z13752A, after the oral administration of rising single doses in healthy volunteers. This study was also a preliminarily investigation of Z13752A pharmacodynamics (PD) and pharmacokinetics (PK). METHODS: In this randomized, placebo-controlled, sequential study, two alternating panels of eight healthy male volunteers each (six subjects receiving the active treatment + two subjects receiving placebo) were treated with increasing oral doses of Z13752A: 10, 50, 200, and 600 mg were given to panel I and 20, 100, 400 and 800 mg were given to panel II. The study was double-blind relative to placebo or active treatment, and was open with respect to the dose levels. The same volunteer received placebo only once. RESULTS: Single oral doses of Z13752A, as high as 800 mg, were well tolerated. Only six mild-to-moderate adverse events mainly headache, were reported and appeared to be of little clinical relevance. After administration of 200, 400, 600 and 800 mg of Z13752A, a nonsignificant fall in diastolic blood pressure was detected, in both the standing and supine position. After single oral doses of Z13752A, ACE inhibition appeared to be significant at all the doses tested, linearly correlated with the dose and was almost complete at doses > or = 100-200 mg. NEP inhibition was indicated by elevation of ANP and cGMP plasma concentrations in almost all subjects. In the 200-800 mg dose range, Z13752A produced a 50-100% increase of plasma cGMP levels and a 50-80% elevation in urinary cGMP concentrations. Detectable plasma levels of Z13752A were found in all the treated subjects. Z13752A was well and rapidly absorbed, with peak concentrations reached approximately 2.5 h after administration. The mean apparent elimination half-life from plasma was approximately 12 h. The pharmacokinetics of Z13752A after single oral doses were characterized by low intersubject variability and appeared to be dose-independent. CONCLUSIONS: Z13752A showed a good single dose tolerability profile at doses up to 800 mg. The pharmacokinetic data indicate that Z13752A administered orally is rapidly absorbed and available to the systemic circulation in humans. The relatively slow clearance indicates that a once-a-day dose regimen could be considered for Z13752A.     

Single-dose pharmacokinetics of repaglinide in subjects with chronic liver disease

Repaglinide is a novel insulin secretagogue developed in response to the need for a fast-acting, oral prandial glucose regulator for the treatment of type 2 (non-insulin-dependent) diabetes mellitus. Repaglinide is metabolized mainly in the liver; its pharmacokinetics may therefore be altered by hepatic dysfunction. This open, parallel-group study compared the pharmacokinetics and tolerability of a single 4 mg dose of repaglinide in healthy subjects (n = 12) and patients with chronic liver disease (CLD) (n = 12). Values for AUC and Cmax were significantly higher in CLD patients compared with healthy subjects, and the MRT was prolonged in CLD patients. Values for tmax did not differ between the groups, but t1/2 was significantly prolonged in CLD patients compared with previously determined values in healthy subjects. AUC was inversely correlated with caffeine clearance in CLD patients but not in healthy subjects. Blood glucose profiles were similar in both groups. Adverse events (principally hypoglycemia) were similar in the two groups; none was serious. Repaglinide clearance is significantly reduced in patients with hepatic impairment; the agent should be used with caution in this group.     

Pharmacokinetics of emedastine difumarate, a new anti-histaminic agent in patients with renal impairment

OBJECTIVE: Emedastine difumarate is a new H1 receptor antagonist with well defined pharmacokinetic and pharmacodynamic profiles in healthy volunteers. However, to date it is not known whether impaired renal function in patients with chronic renal insufficiency affects its pharmacokinetics and probably also its tolerability. Therefore, we here set out to compare the pharmacokinetics of emedastine difumarate in patients suffering from different degrees of renal failure with a control group of healthy volunteers. METHODS AND RESULTS: For this purpose we conducted an open, single-centre, comparative parallel group study in patients and healthy volunteers. Emedastine difumarate 2 mg was administered orally to the study population in single and seven repetitive doses twice daily (b.i.d.). Pharmacokinetics differed markedly between volunteers (n = 6) and patients (n = 17). The maximum serum concentration of emedastine (Cmax), area under the serum concentration-time curve, mean residence time and terminal disposition half-life were significantly higher in patients (P < 0.05), while time to reach Cmax and apparent volume of disposition were not statistically different after single and repeated (steady-state) oral administrations. Blood pressure and heart rate were also not affected by the study medication. CONCLUSION: The present study shows that impaired renal function alters the pharmacokinetics of emedastine in plasma. Thus, dose adjustment of emedastine difumarate is advisable in patients with impaired renal function.     

创新药吡非尼酮胶囊在中国健康人体耐受性和安全性研究

目的：评价中国健康受试者单次和多次口服1.1类创新药吡非尼酮胶囊后的人体耐受性和安全性。方法：依据动物实验结果推算起始和最大剂量，以健康受试者为研究对象，从安全起始剂量开始，进行单次和多次给药耐受性试验。采用随机单中心临床研究，统一餐后给药。单次给药耐受性试验：36例，随机分成6个剂量组：200 mg（2例），400 mg（4例），800 mg（6例），1 200 mg（8例），1 800 mg（8例），2 400 mg（8例）；多次给药耐受性试验：12例，分成2个剂量组：400 mg（6例），600 mg（6例），每天3次，连续给药7 d。观察受试者用药前后症状、生命体征、实验室检查变化（包括血尿常规、肝肾功能、心电图等）、并记录药品不良事件。结果：单次和多次给药耐受性试验的受试者用药前后生命体征和心电图无显著变化，实验室检查等表明无器质性损伤。依据试验终止标准，20例受试者完成4个剂量组的单次耐受性研究。其中单次给药耐受性试验有12例，多次给药耐受性试验有7例受试者在口服药物后出现轻中度恶心、呕吐、烧心、食欲不振、头晕和头痛等不良事件，未经处理自行缓解。本试验过程中未发生严重不良事件。结论：中国健康人体对吡非尼酮胶囊单次（200~1 200 mg）或多次（400~600 mg，tid×7 d）给药的安全性和耐受性良好，将为临床合理应用提供依据。     

Influence of cirrhosis on lamotrigine pharmacokinetics

AIMS: Lamotrigine, an antiepileptic drug, is cleared from the systemic circulation mainly by glucuronidation. The possibility of changes in the pharmacokinetics of lamotrigine in plasma owing to hepatic dysfunction has been evaluated. METHODS: Thirty-six subjects, including 24 patients with various degrees of liver cirrhosis and 12 healthy volunteers received a single 100 mg dose of lamotrgine. Blood samples were taken for 7 days in all subjects, except nine with severe cirrhosis, who had a 29 day blood sampling period. RESULTS: The pharmacokinetics of lamotrigine were comparable between the patients with moderate cirrhosis (corresponding to Child-Pugh grade A) and the healthy subjects. Plasma oral clearance mean ratios (90% confidence interval) in patients with severe cirrhosis without or with ascites (corresponding, respectively, to Child-Pugh grade B and C) to healthy subjects were, respectively, 60% (44%, 83%) and 36% (25%, 52%). Plasma half-life mean ratios (90% confidence interval) in these two patient groups to healthy subjects were, respectively, 204% (149%, 278%) and 287% (202%, 408%). CONCLUSIONS: Lamotrigine administered as a single oral dose of 100 mg was well tolerated in all groups. Initial, escalation and maintenance doses should generally be reduced by approximately 50 or 75% in patients with Child-Pugh Grade B or C cirrhosis. Escalation and maintenance doses should be adjusted according to clinical response.     

奥兰替胃康片I期临床耐受性试验

 　目的：观察奥兰替胃康片（枳实总黄酮苷提取物）在健康志愿者中的安全性和耐受性。方法：单次给药组38名健康志愿者分为7个剂量组,分别给予奥兰替胃康片100,300,600,1 000,1 600,2 400和3 000 mg (1片,n=4;3片,n=4;6片,n=6;10片,n=6;16片,n=6;24片,n=6;30片,n=6)。多次给药组12名健康志愿者分为2个剂量组,分别给予奥兰替胃康片200 mg（2片,n=6）或400 mg（4片,n=6）,tid,连续给药7 d。观察受试者的临床症状和体征、生命体征、实验室检查、心电图检查、腹部彩色B超及不良事件。结果：共32名健康志愿者完成了耐受性试验。单次、多次试验均未发生严重不良事件。单次给药试验和多次给药试验中,受试者均未出现有临床意义的体格检查、实验室检查、心电图检查异常。单次给药1 000 mg组发生了5例不良事件,很可能与试验药物有关;1 600,2 400,3 000 mg组停止进行试验。多次给药试验中无不良事件发生。结论：奥兰替胃康片在100~600 mg范围内用药的安全性和耐受性良好。单次给药的最大耐受剂量为600 mg。多次给药每次200~400 mg,tid,连续7 d安全且耐受性好。推荐的II期临床试验的给药方案为每次400 mg,tid。     

复方氯唑沙宗片人体生物等效性研究

目的:研究2种复方氯唑沙宗片在健康志愿者体内的生物等效性.方法:20例男性健康志愿者随机交叉口服2种制剂(氯唑沙宗500 mg,对乙酰氨基酚600 mg),剂间间隔为1周.以非那西丁为内标,用高效液相色谱法同时测定氯唑沙宗和对乙酰氨基酚的血药浓度.结果:健康志愿者口服复方氯唑沙宗片后对乙酰氨基酚Cmax分别为(14.65±4.10)和(16.95±5.14)μg·mL-1;Tmax,分别为(0.8±0.3)和(0.7±0.3)h;AUC0-12分别为(47.63±13.21)和(48.89±14.43)h·μg·mL-1;t1/2分别为(2.90±0.99)和(2.82±0.62)h.氯唑沙宗Cmax分别为(18.07±5.07)和(18.30±3.31)μg·mL-1;Tmax分别为(1.2±0.5)和(1.1±0.4)h;AUC0-8分别为(43.14±7.33)和(43.90±6.39)h·μg·mL-1;t1/2分别为(1.09±0.17)和(1.12±0.25)h.各参数经统计学双单侧t检验,均有显著性差异(P<0.05).对乙酰氨基酚和氯唑沙宗同种成分的相对生物利用度分别为(109.1±30.9)%和(114.0±50.5)%.结论:2种氯唑沙宗片在健康志愿者体内的药动学参数相似,具有生物等效性.     

Hormonal effects of MPV-2213ad, a new selective aromatase inhibitor, in healthy male subjects. A phase I study

Aims A novel non-steroidal competitive inhibitor of the aromatase enzyme, MPV-2213ad, was entered into an open dose-escalation study. The objective of this study was to investigate the tolerability and efficiency of this new compound with assessment of the hormonal effects after study drug administration.
Methods MPV-2213ad was given to 39 healthy male volunteers. Single increasing oral doses of 0.003, 0.03, 0.3, 3, 9, 30 and 100  mg were given to three subjects at each dose level, after which ten subjects received the 300  mg dose and eight subjects the highest 600  mg dose of MPV-2213ad.
Results Serum oestradiol levels were suppressed by 58–65% when MPV-2213ad was given at doses between 0.3 and 30  mg. A reduction in serum oestradiol levels by 83% from baseline was achieved with the 300  mg dose. No additional decrease was seen with the highest dose. The suppression lasted longer with higher doses of MPV-2213ad. After the 300 and 600  mg doses serum oestradiol returned to baseline within 4 days. Marked increases in serum concentrations of testosterone, androstenedione, 17-OH-progesterone, LH and FSH were also observed at doses between 100 and 600  mg of MPV-2213ad. The drug was well-tolerated and the adverse events were mild or moderate including hot flushes, mild vertigo, nausea, acne and gastrointestinal discomfort.
Conclusions MPV-2213ad has a potent, dose-dependent inhibitory effect on serum oestradiol. It was selective for the aromatase enzyme with no signs of adreno-cortical suppression or haematological or biochemical toxicity.     

Single-dose clinical pharmacokinetic studies of gefitinib

BACKGROUND: The objective of the five clinical studies presented in this article was to investigate the single-dose pharmacokinetics of gefitinib (IRESSA, ZD1839), an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, in healthy volunteers and patients with advanced cancer. METHODS: Studies 1 and 3-5 recruited healthy male volunteers aged 18-65 years; study 2 recruited male or female patients aged>or=18 years with any solid malignant tumour expressing EGFR and refractory to standard therapy. Gefitinib administration was as follows: study 1 (bioavailability in healthy volunteers; n=12)--intravenous infusion of 50 or 100 mg followed by a single oral dose of 250 mg; study 2 (bioavailability in cancer patients; n=19)--intravenous infusion of 50 mg followed by a single oral dose of 250 mg; study 3 (intrasubject variability; n=24)--two single oral doses of 250 mg; study 4 (dose-proportionality; n=15)--three single oral doses of 50-500 mg; study 5 (effect of food; n=26)--two single doses of 250 mg under either fed or fasted conditions. In all studies, venous blood samples for determination of gefitinib plasma concentrations were collected at predetermined intervals. Plasma concentrations of gefitinib were measured using liquid-liquid extraction after basification followed by high-performance liquid chromatography with tandem mass spectrometric detection. Appropriate pharmacokinetic parameters were determined by noncompartmental methods. RESULTS: Study 1: Oral bioavailability of a gefitinib 250 mg dose was 57% in healthy volunteers. Absorption was moderately slow, with geometric mean (gmean) peak plasma concentration (Cmax) of 85 ng/mL (range 43.5-110 ng/mL) reached 5 hours following an oral dose of 250 mg. Study 2: Oral bioavailability of a gefitinib 250 mg dose was 59% in patients. Absorption was again moderately slow, with gmean Cmax of 159 ng/mL (range 48.7-324 ng/mL) typically reached 3 hours (range 1-8 hours) following an oral dose of 250 mg. Study 3: Area under the plasma concentration-time curve from time zero to infinity (AUCinfinity) and Cmax were variable--up to 15-fold between subjects and 2-fold within an individual. Study 4: AUCinfinity and Cmax increased with dose across the range of 50-500 mg, and increased dose-proportionally up to 250 mg. Study 5: Small, clinically insignificant increases in AUCinfinity and Cmax were seen in the presence of food (32% and 37%, respectively). CONCLUSIONS: The gefitinib 250 mg tablet is orally bioavailable in both healthy volunteers and cancer patients; bioavailability is independent of dose and unaffected by food to any clinically significant extent. Gefitinib undergoes rapid plasma clearance and has an extensive volume of distribution, resulting in a pharmacokinetic profile supportive of a once-daily dosage regimen.     

Elevated plasma nilvadipine concentration after single and chronic oral administration to patients with chronic liver disease

Summary Fourteen normotensive patients with liver disease (6 with cirrhosis and 8 with chronic hepatitis) and 7 healthy volunteers were given a single oral dose of nilvadipine 2 mg. In addition, nilvadipine 4 mg was administered orally twice daily for several months to 6 hypertensive patients with mild liver dysfunction and 18 hypertensives with normal liver function.A significant increase in plasma nilvadipine was found in the patients with cirrhosis as compared both to the normal and chronic hepatitis subjects; the time to peak concentration was similar among the three groups.The peak plasma nilvadipine concentration was closely correlated both with the serum albumin level and the retention of indocyanine green. Changes in blood pressure, pulse rate and various vasoactive hormones following a single oral dose of nilvadipine did not differ between the groups.Thus, an increase in plasma nilvadipine relative to the level in normal subjects was demonstrated in patients with cirrhosis following a single oral dose, as well as in patients with slight liver dysfunction following long-term oral administration.     

Pharmacokinetics of sabeluzole and dextromethorphan oxidation capacity in patients with severe hepatic dysfunction and healthy volunteers

AIMS: The primary objective of this study was to determine how the pharmacokinetics of sabeluzole, an investigational drug with specific effects on memory and learning abilities, are affected by chronic liver disease. Since sabeluzole is metabolised by CYP2D6, a secondary objective was to study the correlation between CYP2D6 activity (as assessed by the dextromethorphan dextrorphan metabolic ratio) and hepatic dysfunction. METHODS: The single-dose pharmacokinetics of sabeluzole (10 mg) was compared in 10 healthy Caucasian subjects and 10 patients with severe hepatic dysfunction. The urinary dextromethorphan/dextrorphan (DMP/DRP) metabolic ratio was determined after intake of 20 mg dextromethorphan (NODEX capsules). RESULTS: The terminal half-life of sabeluzole was significantly prolonged in subjects with severe hepatic dysfunction vs healthy subjects (respectively 39.3 +/- 11.5 h; 17.5 +/- 10.2 h (mean +/- s.d.)). The areas under the curve (AUC) were significantly higher in subjects with severe hepatic dysfunction than in healthy volunteers (681 +/- 200 ng ml(-1) h vs 331 +/- 282 ng ml(-1) h). There was a significant correlation between the AUC(0,infinity) and the DMP/DRP metabolic ratio in healthy volunteers and subjects with severe hepatic dysfunction. AUC was greater and elimination of sabeluzole slower in poor metabolizers compared with extensive metabolizers. CONCLUSIONS: These results suggest that a) sabeluzole dose should be reduced in patients with severe hepatic dysfunction and b) the AUC of sabeluzole is linked to individual CYP2D6 activity.     

Pharmacokinetics and safety of single oral doses of sirolimus (rapamycin) in healthy male volunteers

A phase I study was conducted to determine the pharmacokinetics, safety, and tolerability of sirolimus, a new immunosuppressive drug, in 45 healthy men between 19 and 36 years of age. Nine subjects in each group were randomly assigned to receive single oral doses of either sirolimus (n = 6) or placebo (n = 3) in group I (0.3 mg/m2), group II (1 mg/m2), group III (3 mg/m2), group IV (5 mg/m2) and group V (8 mg/m2). No serious adverse events occurred during the study. Twenty-eight of the 45 volunteers (62%) reported an adverse event; 19 of 30 (63%) were in the sirolimus group and 9 of 15 (60%) were in the placebo group (ns). Asthenia was the most common adverse event, occurring in 7 of 30 (23%) in the sirolimus group compared with 6 of 15 (40%) in the placebo group (ns). Absorption occurred within 1 hour in all volunteers. Whole blood peak concentration and area under the concentration-time curve increased proportionally with dose. Mean (+/- SD) whole blood terminal disposition half-life (t1/2), apparent oral dose clearance (Cl/F), and volume of distribution (Vss/F) were 82 +/- 12 hours, 278 +/- 117 mL/h x kg and 23 +/- 10 L/kg, respectively. Distribution of sirolimus into formed blood elements was extensive, with a mean whole blood-to-plasma ratio of 36. Single oral doses of sirolimus (0.3 to 8 mg/m2) solution were well tolerated in healthy male volunteers.     

Tolerability, pharmacokinetics and concentration-dependent hemodynamic effects of oral CF101, an A3 adenosine receptor agonist, in healthy young men

OBJECTIVES: To assess safety, tolerability, pharmacokinetics and hemodynamic effects of oral CF 101, an A3 adenosine receptor (A3AR) agonist, in healthy men. METHODS: One single and 1 repeated dose, parallel-group, ascending dose, double-blind and placebo-controlled study in normal volunteers. In the single dose study, n = 15 subjects received 1, 5 or 10 mg oral CF101; in each group 1 subject received placebo, the remainder active CF101. In the repeat-dose study, n = 28 subjects received repeated 12-hourly oral doses of CF 101 (2, 3, 4 or 5 mg) for 7 days, in each group 2 subjects received placebo, the remainder active CF101. TEST MATERIALS: Single-dose study: CF101 in 30% Cremophor RH40. Multiple-dose sudy: CF101 in 0.5% methylcellulose suspension. Both studies: the corresponding vehicles were used as placebos. Galenicals were prepared remotely from the clinical study site to ensure double-blind nature of the study. RESULTS TOLERABILITY: Single doses up to 5 mg CF101 were safe and well-tolerated. However, the single dose of 10 mg CF101 was associated with flushing, tachycardia, nausea and vomiting, which were viewed as dose-limiting in normal volunteers. Single doses of CF101 (as well as the first of the multiple doses) were associated with increases in heart rate (8 - 24 beats/min after 5 mg and 18 - 55 beats/min after 10 mg). Multiple doses up to 4 mg 12-hourly for 7 days were safe and well-tolerated. However, the 5 mg multiple-dose group reported headache, drowsiness, hot flushes and dizziness on standing; this declined with dosing duration and was not dose-limiting in this study. Adverse events were commonest near t(max). RESULTS PHARMACOKINETICS: For oral CF101, the t(max) was always 1 - 2 h post-dose and t 1/2 about 9 h, in both the single- and multiple-dose studies. For a single 5 mg dose (mean +/- SD) C(max) = 81.6 +/- 23.6 ng/ml in the single dose study, and 63.6 +/- 22.0 ng/ml after the first of the multiple doses; AUC if was 904.0 +/- 221.9 ng.h/ml and 596.1 +/- 196.6 ng.h/ml for the 2 studies, respectively. After 7 days of multiple dosing there was little change, and AUC(0-24h) = 601.0 +/- 163.6 ng.h/ml. These pharmacokinetic parameters were linearly proportional to dose in the other treatment groups. RESULTS PHARMACODYNAMICS: Increases in heart rate were related to plasma concentration and evident only in the upper range of concentrations observed. There were no changes on ECG monitoring beyond sinus tachycardia, and, in particular, no evidence of PR prolongation in any subject (n = 43). In comparison with single doses, this response was almost absent after 7 days of dosing. Leucocytosis (increases up to about 1.5 x 10(9)/l after 5 and 10 mg) was similarly transient and reversible after multiple dosing. CONCLUSIONS: Single oral doses up to 5 mg CF101 and repeated doses up to 4 mg 12-hourly for 7 days were safe and well-tolerated. Multiple-dose CF101 pharmacokinetics were unchanged and predictable from single-dose estimates, and were linearly proportional to dose. Increases in heart rate and neutrophil count were reversible during multiple dosing and were not dose-limiting in the repeat dose study. CF101 warrants further study for its efficacy in treating human disease.     

The effect of acetaminophen administration on its disposition and body stores of sulphate

Summary This investigation was designed to investigate the effects of ingestion of multiple therapeutic doses of acetaminophen on the disposition of the drug and on the cosubstrate, sulfate. Nine healthy volunteers and nine outpatients receiving acetaminophen for chronic pain were involved in the study. Volunteers were given a single 650 mg oral dose of acetaminophen. One week later they were given 650 mg of acetaminophen every six hours for five doses. Patients were maintained on their normal treatment and dosage schedules (600 mg every 3 to 8 h) for the study.In healthy volunteers the half-life of acetaminophen after single and multiple dosing was not significantly different. However, the fraction of acetaminophen recovered in the urine as the sulfate conjugate was less and the glucuronde conjugate greater after multiple dosing than after a single of the drug. There was no difference in the percentage recovered as the-parent compound between single and multiple dosing.Serum sulfate levels fluctuated over the 6-h period following administration of single and multiple doses of acetaminophen to volunteers. The mean serum sulfate concentration was less after administration of five sequential 650 mg doses of acetaminophen than after a single dose. The renal clearance of inorganic sulfate showed a corresponding decrease. Unexpectedly, patients on chronic acetaminophen therapy exhibited elevated serum sulfate levels (levels higher than the maximum sulfate concentration seen in volunteers).     

Pharmacokinetics of modified oral calcitonin product in healthy volunteers

STUDY OBJECTIVE: To assess the preliminary pharmacokinetics, pharmacodynamics, safety, and tolerability of single oral doses of a chemically modified salmon calcitonin product, CT-025, in healthy volunteers. DESIGN: Phase I, exploratory, five-way, open-label, nonrandomized, crossover study. SETTING: Clinical research center. SUBJECTS: Twelve healthy volunteers aged 22-44 years. INTERVENTION: A single oral dose of CT-025 was administered on 5 separate days with a 72-hour washout period between doses. Each dose consisted of CT-025 160 or 320 microg in varying relative concentrations of a mixture of excipients (formulations A, B, and C). MEASUREMENTS AND MAIN RESULTS: Serial blood samples were collected for determination of plasma CT-025, total serum calcium, and ionized serum calcium concentrations during the 4-hour period after dose administration. The data are the results from four of the five dosing days, when subjects received CT-025 in high and low concentrations of excipients. The data indicate that CT-025 was rapidly absorbed from the gastrointestinal tract. Mean peak plasma concentrations ranging from 51+/-51-110+/-59 pg/ml were observed 36-54 minutes after administration. Mean terminal elimination half-lives ranged from 54-76 minutes. There was a trend for the mean maximum concentration and area under the plasma concentration-time curve (AUC) from time zero to the time of the last quantifiable plasma concentration to increase with dose. Single oral doses of CT-025 160 and 320 microg were pharmacologically active, inducing a statistically significant decrease in total and ionized serum calcium concentrations. The rate of decrease in ionized serum calcium concentration was significantly related to the CT-025 dose. Single ora doses were well tolerated; some subjects experienced mild and transient nausea. CONCLUSION: Single doses of CT-025 were absorbed into the systemic circulation after oral administration and were well tolerated in healthy volunteers at doses up to 320 microg. These data suggest that oral delivery of salmon calcitonin becomes feasible with this product and support further clinical investigation of CT-025 as a treatment for osteoporosis and osteoporotic bone pain.     

金玉康胶囊Ⅰ期耐受性临床研究

目的:评价健康人体对金玉康胶囊的耐受性和安全性.方法:将40例受试者随机分为单次给药组和连续给药组.单次给药组分别单次口服金玉康胶囊150,300,450,600,750和900mg;连续给药组以750mg·d-1剂量连续服药7d.观察药物的不良反应、实验室检查、心电图以及生命体征.结果:在单次服药150～900mg及750mg·d-1连续服药7d的观察剂量范围内,金玉康胶囊对健康受试者的生命体征和肝肾功能没有明显影响;主要不良反应有困倦、头晕头痛、口干,个别有恶心呕吐.结论:在观察剂量范围内,金玉康胶囊的耐受性和安全性良好.     

Phase I pharmacokinetic studies evaluating single and multiple doses of oral GW572016, a dual EGFR-ErbB2 inhibitor, in healthy subjects

GW572016 is a dual EGFR-ErbB2 inhibitor that has promise as an anticancer agent. Two phase I studies were conducted to determine the safety, tolerability and pharmacokinetics of single and multiple doses given to healthy subjects. The single dose study evaluated two groups of eight subjects in an ascending dose, 4-way cross-over, while the multiple dose study evaluated twenty-seven healthy volunteers in an ascending dose, double-blind, randomized, placebo-controlled, staggered parallel design. No serious adverse events were seen in either study. The most common adverse events for subjects receiving GW572016 were headache, diarrhea, rash, cold symptoms, gastrointestinal symptoms, and elevated LFTs, which were similar between treatment and placebo groups. Absorption of single doses of GW572016 was slightly delayed, with median t(lag) of 15 minutes (range 0-90 minutes) and achieved peak serum concentrations at a median of three hours (range 1.5-6 hours) post-dose. Serum concentrations after multiple doses of GW572016 demonstrated no significant accumulation at the 25 mg dose, and approximately 50% accumulation at the 100 mg and 175 mg doses, achieving steady state in six to seven days. A modest time-dependent increase in serum concentrations also was detected with multiple doses of GW572016. Single and multiple oral doses of GW572016 were well tolerated in healthy subjects, and resulted in dose-related systemic exposure of GW572016.     

Pharmacokinetics and pharmacodynamics of dabigatran etexilate, an oral direct thrombin inhibitor, are not affected by moderate hepatic impairment

The impact of moderate hepatic impairment on the pharmacokinetics (PK) and pharmacodynamics (PD) of dabigatran etexilate was evaluated in an open, parallel-group study. Healthy volunteers (n = 12) and patients with hepatic impairment (Child-Pugh classification B; n = 12) received a single oral dose of 150 mg dabigatran etexilate. The mean values for area under the concentration-time curve, terminal half-life, and renal clearance of dabigatran were comparable between patients with hepatic impairment and healthy volunteers. Conversion of the dabigatran intermediate BIBR1087 to active dabigatran was slower in patients with hepatic impairment, indicating that the liver is partly involved in bioconversion of dabigatran etexilate. However, total drug exposure was comparable between groups; therefore, this observation is of no clinical relevance with respect to the anticoagulant activity of dabigatran. The extent of dabigatran glucuronidation was unchanged by liver disease; glucuronidation capacity was maintained in moderate liver disease. The activated partial thromboplastin time, ecarin clotting time, and thrombin time relationships were essentially identical in both groups. This study shows that moderate hepatic impairment does not affect the PK/PD or safety profile of dabigatran. Therefore, patients with moderate hepatic impairment can be given dabigatran etexilate without the need for dose adjustment.     

健康志愿者单次口服壮骨胶囊的安全性及耐受性研究

目的评价健康志愿者口服壮骨胶囊的安全性和耐受性.方法 34名年龄19～26岁的健康志愿者,男女各半,筛选合格后根据性别和体重随机分为600、1 200、1 800、2 400及3 000 mg 5个剂量组(每组4～8人),由最小剂量组开始,逐组进行试验.观察指标有临床症状、生命体征、心电图、血常规、尿常规、血生化、凝血功能、性激素等.结果给药后各组志愿者的生命体征、心电图、血常规、尿常规、凝血功能未发现有临床意义的异常变化.结论单次口服壮骨胶囊的剂量在3 000 mg内安全,志愿者耐受性良好.