A first-in-human study of DS-1040, an inhibitor of the activated form of thrombin-activatable fibrinolysis inhibitor, in healthy subjects.

Essentials DS-1040 inhibits the activated form of thrombin-activatable fibrinolysis inhibitor (TAFIa). Infusion of DS-1040 was safe and well tolerated in healthy young and elderly subjects. DS-1040 substantially decreased TAFIa activity but had no impact on bleeding time. DS-1040 may provide an option of safer thrombolytic therapy. SUMMARY: Background Current treatments for acute ischemic stroke and venous thromboembolism, such as recombinant tissue-type plasminogen activator and thrombectomy, are limited by a narrow time window and the risk of bleeding. DS-1040 is a novel low molecular weight compound that inhibits the activated form of thrombin-activatable fibrinolysis inhibitor (TAFIa), and was developed as a fibrinolysis enhancer for the treatment of thromboembolic diseases. Objectives This first-in-human, randomized, placebo-controlled, three-part, phase 1 study was conducted to evaluate the safety, pharmacokinetics and pharmacodynamics of DS-1040 in healthy subjects. Subjects/Methods Young (18-45 years) or elderly (65-75 years) subjects (N = 103) were randomized to receive single ascending doses of DS-1040 ranging from 0.1 mg to 40 mg, or placebo, administered either as a 0.5-h intravenous infusion or as a 24-h continuous infusion. Results All doses of DS-1040 were tolerated, and no serious adverse events (AEs) or discontinuations resulting from AEs occurred during the study. Bleeding time remained within the normal range for all doses tested in all subjects. Plasma exposure of DS-1040 increased proportionally with increase in dose. Elderly subjects had higher exposures to DS-1040 and prolonged elimination times, probably because of decreased renal clearance. DS-1040 caused a substantial dose-dependent and time-dependent decrease in TAFIa activity and in 50% clot lysis time. The levels of D-dimer, indicative of endogenous fibrinolysis, increased in some individuals following DS-1040 treatment. No effects of DS-1040 on coagulation parameters or platelet aggregation were observed. Conclusions The novel fibrinolysis-enhancing agent DS-1040 has favorable pharmacokinetic/pharmacodynamic properties and a favorable safety profile, warranting further clinical development.

Disposition and biotransformation of the antiretroviral drug nevirapine in humans.

The pharmacokinetics and biotransformation of the antiretroviral agent nevirapine (NVP) after autoinduction were characterized in eight healthy male volunteers. Subjects received 200-mg NVP tablets once daily for 2 weeks, followed by 200 mg twice daily for 2 weeks. Then they received a single oral dose (solution) of 50 mg containing 100 microCi of [(14)C]NVP. Biological fluids were analyzed for total radioactivity, parent compound (HPLC/UV), and metabolites (electrospray liquid chromatography/mass spectroscopy and liquid chromatography/tandem mass spectroscopy). Mean recovery of radioactivity was 91.4%, with 81.3% excreted in urine and 10.1% recovered in the feces over a period of 10 days. Circulating radioactivity was evenly distributed between whole blood and plasma. At maximum plasma concentration, parent compound accounted for approximately 75% of the circulating radioactivity. Mean plasma elimination half-lives for total radioactivity and NVP were 21.3 and 20.0 h, respectively. Several metabolites were identified in urine including 2-hydroxynevirapine glucuronide (18.6%), 3-hydroxynevirapine glucuronide (25.7%), 12-hydroxynevirapine glucuronide (23.7%), 8-hydroxynevirapine glucuronide (1.3%), 3-hydroxynevirapine (1.2%), 12-hydroxynevirapine (0.6%), and 4-carboxynevirapine (2.4%). Greater than 80% of the radioactivity in urine was made up of glucuronidated conjugates of hydroxylated metabolites of NVP. Thus, cytochrome P-450 metabolism, glucuronide conjugation, and urinary excretion of glucuronidated metabolites represent the primary route of NVP biotransformation and elimination in humans. Only a small fraction of the dose (2.7%) was excreted in urine as parent compound.

A phase I/II study of the safety and pharmacokinetics of nevirapine in HIV-1-infected pregnant Ugandan women and their neonates (HIVNET 006).

OBJECTIVE: To determine the safety, pharmacokinetics, tolerance, antiretroviral activity, and infant HIV infection status after giving a single dose of nevirapine to HIV-1-infected pregnant women during labor and their newborns during the first week of life. DESIGN: An open label phase I/II study. SETTING: Tertiary care hospital, Kampala, Uganda. PATIENTS AND INTERVENTIONS: Nevirapine, 200 mg, was given as a single dose during labor to 21 HIV-1-infected pregnant Ugandan women. In cohort 1, eight infants did not receive nevirapine whereas in cohort 2, 13 infants received a single dose of nevirapine, 2 mg/kg, at 72 h of age. OUTCOMES: The number and type of adverse events; nevirapine concentrations in the plasma and breast milk; maternal plasma HIV-1 RNA copy number before and up to 6 weeks after delivery; and HIV-1 infection status of the infants were monitored. RESULTS: Nevirapine was well tolerated by women and infants; no serious adverse events that were related to nevirapine were observed. Median nevirapine concentration in the women at delivery was 1623 ng/ml (range 238-2356 ng/ml); median cord/maternal blood ratio of 0.75 (0.37-0.93). The median half-life in women was 61.3 h (27-90 h) and the transplacental nevirapine half-life in infants who did not receive a neonatal dose was 54 h. The median half-life after a single dose at 72 h in infants was 46.5 h. During the first week of life, the median colostrum/breast milk to maternal plasma nevirapine concentration was 60.5% (25-122%). The median nevirapine concentration in breast milk 1 week after delivery was 103 ng/ml (25-309 ng/ml). Plasma nevirapine concentrations were above 100 ng/ml in all infants from both cohorts tested at age 7 days. Maternal HIV-1 RNA levels decreased by a median of 1.3 logs at 1 week postpartum, and returned to baseline by 6 weeks postpartum. Detectable plasma HIV-1 RNA was observed in one out of 22 (4.5%) infants at birth; three out of 21 (14%) at 6 weeks; and four out of 21 (19%) at 6 months of age. CONCLUSION: The administration of a single dose of nevirapine to women during labor and to their newborns at 72 h was well tolerated and showed potent antiretroviral activity in the women at 1 week after dosing without rebound above baseline 6 weeks after a single dose. The nevirapine concentration was maintained above the target of 100 ng/ml in infants at age 7 days, even in those infants not receiving a neonatal dose. This regimen has promise as prophylaxis against intrapartum and early breast milk transmission in a breastfeeding population.

Single dose pharmacokinetics and bioavailability of nevirapine in healthy volunteers.

The results of two randomized, single-dose, crossover bioavailability studies are presented which describe the pharmacokinetics and oral bioavailability of nevirapine, a novel nonnucleoside antiretroviral drug. In the first study 12 healthy male volunteers received nevirapine 15 mg via short-term i.v. infusion or orally as a 50 mg tablet or reference solution (50 mg/200 mL). Following the i.v. dose, nevirapine had a low systemic clearance (Mean +/- S.D., Cl = 1.4 +/- 0.3 L/h) and a prolonged elimination phase (t(1/2beta) = 52.8 +/- 14.8 h; MRT = 81.4 +/- 22.4 h). Nevirapine absolute bioavailability was 93 +/- 9% and 91 +/- 8% for the tablet and oral solution, respectively. In the second study, 24 healthy male volunteers were administered nevirapine as a 200 mg production-line tablet or oral reference solution (200 mg/200 mL). There was no significant difference in bioavailability between the tablet and reference solution. Overall, comparison of the pharmacokinetic parameters between the 50 and 200 mg doses indicates that nevirapine is well absorbed at clinically relevant doses. The absorption profiles using deconvolution revealed no evidence of differential enzyme induction between the two doses or routes of administration following a single dose.

HPLC-UV method for the quantitation of nevirapine in biological matrices following solid phase extraction.

Nevirapine (VIRAMUNE) is a non-nucleoside reverse transcriptase inhibitor with activity against human immunodeficiency virus type 1 (HIV-1), currently marketed for the treatment of HIV-1 infected adults. A reverse phase HPLC-UV method was optimized and validated for the determination of nevirapine in human plasma, serum, milk and cerebrospinal fluid. The analyte was extracted from 250 microl of biofluid using a bonded silica solid phase extraction column, and resolved chromatographically on a reversed-phase, 15x0.46 cm i.d. 5 microm particle Supelco LC-8 analytical column with an isocratic mobile phase of 63% phosphate buffer (0.025 M, pH 6.0) with 1-butanesulfonic acid as anion-pair reagent: 21.5% methanol: 15.5% acetonitrile. The peaks were detected at a flow rate of 1.0 ml min(-1), at a wavelength of 280 nm, with a run time of 10 min. The assay was linear over a range of 25 to 10000 ng ml(-1). This method has been used for the clinical development of nevirapine.

[Personal experience with the treatment of organic hyperinsulinism]. / Nase zkusenosti s lécbou organického hyperinzulinismu.

In 1981-1997 at the Third Medical Clinic 52 patients with confirmed organic hyperinsulinism were treated. Forty-three were operated and the remaining nine were treated conservatively. An insulinoma was removed surgically in 35 patients, in one female microadenomatosis was detected. The operation was successful in 84%, while topographic preoperative examination aroused suspicion of a focus (i.e. insulinoma) only in 49% of the operated patients. A total of 11 patients (four after surgery and seven not operated) were treated successfully with diazoxide, in nine patients this treatment is still administered. According to the response to diazoxide it is possible to differentiate "responsive" and "non-responsive" insulinomas. Pharmacological treatment is thus justified only in the first group of patients. Surgically and pharmacologically treated patients have no signs of hyperinsulinism. The authors experience suggests that surgical treatment is indicated when the diagnosis is unequivocal even when the topographic finding of imaging methods is negative, as in 35% of operated patients the insulinoma was found only on operation.

Pharmacokinetics of nevirapine in human immunodeficiency virus type 1-infected pregnant women and their neonates. Pediatric AIDS Clinical Trials Group Protocol 250 Team.

The safety, toxicity, and pharmacokinetics of intrapartum and early newborn nevirapine were evaluated in 17 human immunodeficiency virus type 1-infected women in labor and their newborns. No adverse effects of nevirapine were noted in any study mothers or infants. Following maternal dosing with 200 mg during labor, concentrations exceeding 100 ng/mL (10 times the in vitro IC50) were achieved in the newborns. Nevirapine elimination was prolonged in both mothers and infants, with median half-lives ranging from 36.8 to 65.7 h. Administration of 200 mg orally to the mothers in labor and of a single 2-mg/kg oral dose to the infants at 48-72 h after birth maintained serum concentrations in the infants > 100 ng/mL through 7 days of life.

Prophylaxis against HIV-1 infection in chimpanzees by nevirapine, a nonnucleoside inhibitor of reverse transcriptase.

Chimpanzees were challenged with HIV-1IIIB while receiving a short regimen of nevirapine (Viramune), a nonnucleoside inhibitor of HIV-1 reverse transcriptase. The untreated, control chimpanzee developed an infection characterized by seroconversion, viremia in peripheral blood mononuclear cells (PBMCs), and plasma positive for viral RNA. In contrast, the three nevirapine-treated chimpanzees remained negative for all viral markers with the exception of nested polymerase chain reaction (PCR) analysis of PBMCs for viral DNA. Although PBMCs from the three nevirapine-treated chimpanzees tested intermittently positive for viral DNA, this PCR signal disappeared and remained negative for the final five months of the study. These data indicate that orally administered nevirapine provided protection from HIV-1 infection in the chimpanzee model.

[Personal experience with the diagnosis of organic hyperinsulinism]. / Nase zkusenosti s diagnostikou organického hyperinzulinismu.

The diagnosis of organic hyperinsulinism was established in 47 patients based on the typical clinical symptomatology supported by laboratory evidence of hypoglycaemia and raised serum insulin concentrations. For the diagnosis of the disease the test of controlled fasting is suited best. During this test and after its termination the blood sugar level (in mmol/l), serum insulin (in mU/l) and their ratio (insulin/blood sugar) are assessed. In all patients the test had to be discontinued because clinical manifestations of hypoglycaemia developed which are typical for organic hyperinsulinism. Other methods, incl, examination by means of an isoglycemic clamp or insulin receptors are not specific and cannot be used for diagnosis. As to imaging (localisation) methods in the examined group the lowest yield was obtained by computed tomography (positive only in one patient), better results were obtained by sonography (21%) and angiography resp, (45%). When methods were combined an insulinoma was detected in 55% patients while on operation it was found in 82% patients. The authors' experience provides evidence that for the diagnosis of organic hyperinsulinism a decisive role is played by the clinical symptomatology supplemented by laboratory evidence of hypoglycaemia and possibly by a raised serum insulin concentration.

[Factors with insulin-like effects: IGF-I and GLP-1]. / Pusobky s inzulinovým úcinkem: IGF-I a GLP-1.

In the submitted review the author discusses two substances secreted into the circulation which can similarly as insulin lower the blood sugar level. These substances are IGF-I (insulin-like growth factor I) and GLP (glucagon-like peptide). While in case of the former it is not certain whether it participates in the glucose homeostasis, this is beyond doubt in the latter. IGF-I prepared by the recombinant technique can be used therapeutically in cases of insulin resistance caused by a receptor or postreceptor disorder, because it may act via its own receptor. Side-effects after larger doses are a problem. GLP-1, the use of which would be useful in type 2 diabetics as it stimulates insulin secretion, is not used so far in therapy because hitherto prepared preparations have a very short period of a effectiveness.

Clinical research of glucose metabolism.

Glucose metabolism in diabetes and in hypoglycemic states has been studied at IIIrd Medical Department for more than 30 years. The research is now concentrated on the evaluation of insulin action on receptor and postreceptor levels and in biochemical changes accompanying early stages of diabetic microangiopathy. The changes of insulin action has been examined by using the clamp techniques also in patients with organic hyperinsulinism. We study molecular changes of insulin action and pathogenesis of vascular complications.

[Thoughts on insulin therapy]. / Zamyslení nad lécbou inzulinem.

The submitted review concentrates on several important features of contemporary insulin treatment of diabetes (1). Only in the minority of cases, and only in insulin-dependent diabetes typical substitution treatment is involved. Even if it approaches physiological conditions, either by a permanent insulin supply beneath the skin by means of a pump, or using the tactics of several injections per day in the system called "basal bolus", it differs from the latter by the fact that it supplies insulin first into the peripheral circulation and not into the liver and does no imitate the pulsatile character of insulin secretion (2). Contemporary insulin preparations imitate only imperfectly the physiological rapid post-prandial rise of insulinaemia with a subsequent rapid drop. In an attempt to approach this as closely as possible various insulin analogues are used and substitution of amino acids in its molecules by others (3). The antibody formation against insulin was restricted to a great extent by the introduction of mono-component insulin but was not eliminated even when biosynthetic human insulin is used. The importance of these antibodies is, however, in common cases small and is manifested by a prolonged period of action (4). Non-substitutional insulin administration in non-insulin dependent diabetes is indicated where without it satisfactory compensation of diabetes is not achieved. There are favourable reports on combined treatment with insulin and oral antidiabetics in this type. The risk are in particular undesirable body weight increments.

[Hypoglycemia and modern treatment of diabetes]. / Hypoglykémie a soucasná lécba cukrovky.

During insulin treatment, when the objective is to achieve blood sugar levels as close as possible to normal values by an intensified regime, hypoglycaemia is three times as frequent as compared with the conventional regime. The author discusses in the submitted review the relationship between a reduced blood sugar level and associated symptoms, he describes the counterregulation reparative response and draws attention to its changes in conjunction with prolonged duration of diabetes and mentions short-term as well as long-term consequences of hypoglycaemia. In the conclusion he mentions possible ways how to prevent this complication of insulin treatment.

Risk calculation of type 2 diabetes.

The paper presents an analysis of the risk of developing Type 2 diabetes according to family history and anthropometric variables. The age of diabetes onset was analysed in 2024 diabetics. We obtained several groups according to family history. In each group taken separately, the data describing the cumulative percentage of diabetes onset was fitted by logistic curve F(x) = p1/(1 + p2*p3((x/10)-p4)). Comparing these curves we see that cumulative age-dependent risk increases from the group of randomly chosen persons through the group of first degree relatives to the children of diabetics. The highest risk of diabetes onset is determined by the curve representing the group of known diabetics. Another analysis was performed in a different group of 390 obese subjects (34 diabetics among them). Male diabetics had significantly higher body mass index (BMI) and weight than male non-diabetics. Female diabetics showed significantly higher weight, body mass index, waist to hip ratio (WHR) and age than female non-diabetics. Elimination of factors with randomization and matching showed a complicated relationship between diabetes, age and anthropometric variables. Using stepwise logistic regression we obtained the model for prediction of diabetes risk based on age, BMI, WHR: probability of diabetes = exp(u)/(1 + exp(u)), where u = -13.9 + 0.05431*age + 6.789*WHR + 0.07881*BMI for obese women, u = -11.84 + 10.01*WHR for obese men. In conclusion, genetic factors are the most important and can be exactly quantified in Type 2 diabetes. The importance of anthropometric variables for prediction of diabetes risk is also presented.

Pharmacokinetics of nevirapine: initial single-rising-dose study in humans.

Nevirapine, a nonnucleoside inhibitor of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase, was administered for the first time to humans in a pilot study designed to investigate the pharmacokinetics and tolerance of the drug following single-dose administration to 21 HIV-1-infected individuals. The study followed a parallel design. Different groups of three subjects each were given one of seven dose levels (2.5 to 400 mg) in sequential order, starting with the lowest dose. Each subject received only one dose. Nevirapine was rapidly absorbed at all doses from a tablet formulation. Peak concentrations in plasma were generally achieved within 90 min of dose administration. Secondary peaks were also noted between 3 and 12 h or between 24 and 28 h, the latter being noted mainly in subjects receiving the higher doses. After 24 h, concentrations in plasma declined in a log-linear fashion. The terminal half-life and mean residence time exceeded 24 h in all but one subject, indicating a prolonged disposition time in this population. Both peak concentrations in plasma and areas under the plasma concentration-time curves increased proportionally with increasing dose from 2.5 to 200 mg; however, the increase in the peak concentration in plasma and the area under the plasma concentration-time curve appeared to be less than proportional at the 400-mg dose level in this small number of subjects. This observation may be due to increased clearance or decreased absorption at the highest dose or population differences in absorption or clearance between doses. Studies with a cross-over design are planned to resolve these issues. The pharmacokinetic characteristics of nevirapine are appropriate for once-daily administration. A daily 12.5-mg dose is predicted to achieve trough concentrations in plasma in the range required to totally inhibit replication of wild-type HIV-1 in human T-cell culture.

[Evaluation of the status of diabetes mellitus during a 2-year period using traditional methods and determination of glycosylated hemoglobin A1c and fructosamine in the blood]. / Hodnoceni stavu cukrovky v prubehu dvou let tradicnim zpusobem a s pouzitim stanoveni glykovaného hemoglobinu A1c a fruktózaminu v séru.

In the course of two years the authors checked 23 diabetic patients (13 type 2, 10 type 1), using the traditional approach, by assessment of haemoglobin A1c and serum fructosamine. The patients were classified according to compensation into four and three groups resp. Assessment of haemoglobin A1c evaluated the patients, in the same group as the traditional evaluation in 57.7% into the best compensated group and in 62.5% into the worst compensated group. In fructosamine agreement with traditional evaluation in the best compensated group was in 84.2% and in the worst compensated group in 50.0%. In 40.2% the evaluation was in agreement for all three methods of evaluation, differences between evaluation according to haemoglobin A1c and serum fructosamine were recorded in 51.5%. Assessment of haemoglobin A1c and serum fructosamine improves information on the state of diabetes, concurrent estimation of both is, however, often associated with difficulties as regards interpretation. These problems are discussed in the presented paper.

[Variations in the dietary regimen in type I diabetes mellitus. I. Short-term use of a high-carbohydrate diet]. / Odchylky dietního rezimu u diabetu mellitu I. typu. I. Krátkodobé uzití diety s vysokým obsahem sacharidu.

For a period of two days, while maintaining compensation of diabetes mellitus type I (treated by insulin pump), the authors replaced the usual diabetic diet by a bland carbohydrate diet (2.6 +/- 0.6 MJ/24 h, practically without amino nitrogen). This resulted in a negative energy and nitrogen balance with an indicated adaptation reaction on the second day of administration--reduced amount of catabolic urinary nitrogen, concentration of non-esterified serum fatty acids suggested a slightly increased lipolysis. The insulin consumption per 24 h was significantly reduced, as compared with the control day. A low energy carbohydrate diet is, when administered for a short period under careful control of compensation of diabetes type I, relatively safe and can be used e. g. during intercurrent digestive diseases.

[Changes in the dietary regimen during treatment of type I diabetes mellitus with continuous insulin infusion. II. Omitting food]. / Vliv zmen dietního rezimu pri lécbe diabetu mellitu I. typu kontinuální podkozní infúzí inzulínu. II. Vynechání jídla.

UNLABELLED: The authors investigated in 11 type diabetics the effect of omission of a meal on the compensation of diabetes during treatment with an insulin pump IP 1003. After stabilization of treatment by the pump, the patients were left on the 5th day without breakfast, while the basal operation of the pump was maintained and the patient received their insulin bolus in the morning. The test was terminated as planned after 180 mins. in 6 patients, in 5 it was terminated early because of typical signs of clinical hypoglycaemia. The course of the blood sugar curves revealed differences between patients from abrupt drops of hyperglycaemic values to hypoglycaemia to balanced low blood sugar levels. For the rest of the day till the following morning after the test the blood sugar was elevated, as compared with the control level of the 4th day. CONCLUSIONS: the tests revealed the relatively small drop of the blood sugar level after omission of the meal, hypoglycaemia develops in the majority of diabetics only after 120 to 180 mins. The danger of early hypoglycaemia within 60 minutes was recorded only in patients with a known history of severe hypoglycaemic states. Posthypoglycaemic hyperglycaemia influences the compensation of diabetics during the rest of the day.

[The development of theories on the mechanisms of insulin action]. / Vývoj teorií o mechanismu pusobení inzulínu.

In 1924 Laufberger formulated his block theory on the action of insulin. Its basic thesis that insulin prevents the new formation of glucose and its supply into the blood stream is still valid, although knowledge on the multiple action of insulin expanded substantially. The theory put forward in 1955 by Levine and Goldstein which ascribed all insulin actions to the influence on the cellular membrane permeability for glucose, could, however, not explain all data associated with insulin, the knowledge of which was expanded steadily. At present the mechanism of insulin action is explained most comprehensively by the concept based on the bond of insulin to its membrane receptor which by activation of tyrosine kinase it contains induces either cascade phosphorylation of intracellular protein kinases or (and) leads to the release of the "second messenger" from the cell membrane, i.e. of glycosyl-phosphatidyl inositol. In both instances activation of the glucose and amino acids transmitter from the medium into the cells results, as well as activation of enzymes catalyzing in the cell various degrees of carbohydrate, fat and protein metabolism.