International journal of clinical pharmacology, therapy, and toxicology最新文献

The current status of clinical pharmacology (CP) in the countries of the former Eastern block is presented. The difficulties in obtaining an accurate comparative view are pointed out. CP is unevenly developed in Eastern European countries and the number of hours devoted to basic/clinical pharmacology differs considerably 100/nil to 240/50. The same is true for the orientation of clinical pharmacology, where present. It is mainly basic in only a few countries (Rumania, Turkey, some parts of the former Yugoslavia) and mainly clinical in Czecho-Slovakia, Croatia, Hungary, Poland, Greece. The number of CP units and CP specialists varies greatly as well (from none to more than 10 per country). The awareness that CP, in many countries is still young and the branch of (clinical) medicine is of great importance, not only for rational pharmacotherapy but also for other services as well, education and research is growing. In spite of the fact that the present status of CP in Eastern European countries is generally unsatisfactory, there are realistic chances that in the (near?) future, CP will develop to match the activities now present in the more developed countries.

The pharmacokinetics and pharmacodynamics of pravastatin 20 mg administered twice daily when taken with or one hour before meals were evaluated in 24 hypercholesterolemic men in an 8-week, open-label, randomized, two-way crossover study. The bioavailability of pravastatin was reduced significantly (p < or = 0.001) when it was taken with meals (AUC dropped 31% and Cmax dropped 49%), and mean Tmax increased 50% (p < or = 0.01). The mean elimination t1/2 was unaffected by taking pravastatin with food. However, reductions in mean total cholesterol and low density lipoprotein cholesterol were identical whether pravastatin was given with or before meals. In both treatment groups, total cholesterol and low-density lipoprotein cholesterol were significantly reduced from baseline (p < 0.001). These results indicate that although the bioavailability of pravastatin is reduced when taken with meals, the lipid-lowering efficacy of pravastatin is not altered. It can be concluded that pravastatin can be ingested without regard to meal time.

Disopyramide, an antiarrhythmic drug, is known to impair cardiac function, but acute cardiac effects of conventional oral dose of disopyramide are not well known. To examine the extent of acute cardiac effects of daily oral dose of disopyramide, we gave 150 mg of disopyramide to thirteen patients with normal or impaired cardiac function, and observed cardiac function on an hourly basis for 3 hours after baseline period. The serum level of disopyramide reached a therapeutic level (2.0-5.0 micrograms/ml) mostly 1 hour after administration. Doppler-echocardiographically determined left ventricular ejection fraction, and the ratio of the peak early filling velocity to the peak atrial filling velocity in left ventricular inflow velocity remained unchanged throughout the experimental period. Other hemodynamic variables, such as blood pressure and heart rate remained unchanged. We conclude that daily oral dose of disopyramide appears to have no significant effects on cardiac function after administration. Disopyramide seems to be safe and may not be necessarily withheld from patients who need it, when hemodynamic variables are to be measured.

The effects of different doses of sodium bicarbonate on the absorption and activity of non-micronized glibenclamide were studied in six healthy volunteers, using a randomized crossover design with four phases. The subjects ingested a single dose of non-micronized glibenclamide (2.5 mg) with 150 ml of water or with 150 ml of water containing 0.3, 1.0 or 3.0 g of sodium bicarbonate. Plasma concentrations of glibenclamide, insulin and glucose were measured. Coadministration of 1.0 or 3.0 g of sodium bicarbonate with non-micronized glibenclamide increased the area under the plasma glibenclamide concentration-time curve (AUC) from 0 to 1 h 30-fold (p < 0.05) and 38-fold (p < 0.05), respectively. The 1.0- and 3.0-g doses of sodium bicarbonate also increased the AUC of plasma glibenclamide from 0 to 2 h, about 3-fold (p = 0.05 and 0.07, respectively). The peak plasma concentration, peak time and total extent of absorption of glibenclamide and the insulin and glucose responses were not significantly altered by any of the doses of sodium bicarbonate studied. Concomitant ingestion of 1.0 or 3.0 g of sodium bicarbonate and non-micronized glibenclamide greatly increased the early bioavailability of glibenclamide. However, this interaction did not alter the activity of glibenclamide.

Serum proteins are non-enzymatically glycosylated dependent on the concentration of free glucose and measurements of their concentration are used to control diabetic carbohydrate metabolism. Eight patients with insulin-dependent diabetes mellitus (IDDM) and 8 patients with non-insulin-dependent diabetes mellitus (NIDDM) with glycosylated hemoglobin levels of at least 10.5% were studied during a 6-week period of antidiabetic therapy. Glycosylated serum albumin (GSA) and glycosylated total serum proteins (GSP) were measured weekly using an affinity chromatography procedure. The fructosamine test (FA) and the measurement of mean blood glucose (MBG) were also carried out weekly. Glycosylated hemoglobin and its glucose adduct HbA1c were determined at 14-day intervals (HPLC-method). All measured parameters decreased during the period of the study. The correlation coefficients for the glycosylated proteins versus the MBG determined one week earlier were highest for GSA [IDDM: r(GSA/MBG-1) = 0.726, p < 0.001 for the single values and 0.984, p < 0.001 for the mean values; NIDDM: r (GSA/MBG-1) = 0.636, p < 0.001 for the single values and 0.986, p < 0.001 for the mean values]. The differences between the IDDM and NIDDM group probably occurred because 6 NIDDM patients were taking glibenclamide (7.0-10.5 mg/day) which is known to inhibit the glycosylation reaction of albumin. The fructosamine test is more prone to interferences than the selective determination of GSA. GSA determination therefore, gives precise data in medium term diabetic control.

A prospective, open, multicenter clinical trial was set up to evaluate the potential interaction of ITF 282 with H2-receptor antagonists in patients affected with iron deficiency. Patients treated with H2 blockers and affected with iron deficiency or iron deficient anemia were given one tablet of ITF 282 (60 mg iron) twice daily for 60 days. A second group of iron deficient patients with no anti H2 concurrent treatment were admitted to the same iron treatment, lasting 60 days. To evaluate the outcome of the iron treatment, a comprehensive assessment of laboratory and clinical determinations was adopted in all the patients: special hematology, symptomatology, safety hematology and hematochemistry, urinalysis. Fifty-three patients with iron deficiency and 47 patients affected with overt iron deficient anemia entered the study. After treatment, a significant trend toward the normalization of the main hematologic parameters in both groups was detected. The general tolerability was apparently more favorable in the patients who had also the antiulcer (1 event of diarrhoea) than in those who had ITF 282 alone (2 heartburn, 3 constipation, 2 abdominal pain). There were no indications of subgroups of patients particularly at risk of adverse events, all of which resulted reversible without the need to reduce the dose of medication or to take other medical action. ITF 282 resulted, also when administered together with H2-receptor antagonists, in the expected therapeutic efficacy, with the expected clinical tolerability and biological safety, without signs of possible interaction, negative or positive.(ABSTRACT TRUNCATED AT 250 WORDS)

E2020 is a new cholinesterase inhibitor with a novel chemical structure, which is under clinical investigation for use in Alzheimer's disease in Japan and the USA. Three separate studies were conducted to evaluate the safety and to establish the pharmacokinetic profile of E2020 after oral administration to healthy male subjects. E2020 was administered as: (1) single oral doses (0.3 mg, 1 mg, 2 mg, 5 mg, 8 mg and 10 mg) in a fasting condition, (2) a single oral dose (2 mg) after a meal and (3) repeated oral doses (2 mg once daily for 21 days). The concentrations of E2020 and its metabolites in plasma, serum, urine and feces were determined by HPLC methods with UV detection. E2020 was generally well tolerated by all subjects. In the single-dose study, there was a linear relationship between dose and mean AUC. The mean plasma half-life was about 50 hours and was dose-independent. The total clearance and renal clearance of E2020 were also dose-independent and the mean values after 10 mg dosing were 9.7 l/hour and 0.86 l/hour, respectively. The cumulative total urinary and fecal excretion of the sum of unchanged E2020 and its metabolites at 264 hours after the administration of the single 10-mg-dose was 36.1% and 8.6% of the dose, respectively. The mean serum protein binding was 92.6%. No effect of food intake on the pharmacokinetics was observed. Evaluation of the mean trough levels and AUC0-24 of E2020 indicated that a steady-state was achieved after approximately 2 weeks of daily dosing.

A randomized phase-I study was performed in a clinical setting in 24 healthy young male subjects, aged 20 to 35 years, to investigate the influence of Ubretid on AChE inhibition following oral and i.m. administration in one of three medication schemes: -single oral (10 mg) and i.m. (0.5 mg) medication (randomized crossover), -multiple oral dosing (5 mg on trial days 1, 2, 3, 5, 7, 9, 11 and 13), -multiple oral dosing (5 mg on trial days 5 to 14) with initial i.m. loading doses (0.5 mg i.m. on trial days 1, 2 and 4). The multiple dosing schemes were chosen as they are both frequently used in clinical practice. The results of the AChE inhibition after Ubretid can be summarized as follows: repeated Ubretid administration as used in this trial did not lead to a cumulation of AChE inhibition. Statistical testing (page test) of maximum AChE inhibition on the last medication days gave no indication of an increased AChE inhibition towards the end of treatment. Compared with the i.m. administration, the Ubretid tablet had a bioavailability of 2.2 +/- 1.1% (mean +/- STD).

The article is a critical review of recent publications on myeloid hemopoietic growth factors. They are glycoproteins that regulate the proliferation and differentiation of hemopoietic progenitor cells and the function of mature blood cells. They are also named colony stimulating factors after the experimental technique that led to their discovery. Myeloid growth factors are: granulocyte macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), macrophage colony-stimulating factor (M-CSF) and interleukin-3. Studies of hemopoietic growth factors in the past years have revealed many potential beneficial effects, but some limitations as well. They have been proved effective, above all, in neutropenic conditions of different origin. A large number of clinical trials have shown their beneficial effect in myelosuppressive conditions after cytotoxic chemotherapy, in post-transplant period in bone marrow transplantation procedures and in neutropenic conditions as part of other clinical entities. Although a number of studies that should determine their clinical role more clearly is still underway, it seems certain that myeloid hemopoietic growth factors already have an important role in modern pharmacotherapy.

Modification of cardiac beta-adrenergic receptors (beta-AR), resulting from the stimulation of the sympathetic nervous system, is one of the most important factors in the generation of cardiac hypertrophy and heart failure. In this research, we propose the utilization of adipocytes as an alternative to the use of predominantly beta 2-AR subtype containing circulating lymphocytes for the convenient assessment of cardiac failure in the experimentally, volume-overload induced heart hypertrophy in rats. Using this model, we measured beta-AR both in the heart and adipocytes of male rats 2, 7, 21 and 56 days after creating an aorta-cava fistula. Whereas an increase (58%) in cardiac beta-AR density from day 7 to 21 was followed by a decrease in this measurement (30%) on day 56 [changes expressed as percentage of controls; no significant changes in beta-AR affinity (Kd) were recorded at any of the time interval studied], adipocytes beta-AR density showed a progressive increase starting on day 21 (87%) which continued until the end (131%) of the study period. This lack of correlation of the beta-AR population in both tissues supports the need for a specific evaluation of the beta 1-AR subtype in the heart and adipocyte in order to evaluate the usefulness of adipocyte cells as an alternative to assess cardiac failure.