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Biomedical subjects

G Hitzenberger

Publications and source records attributed to G Hitzenberger.

At least 55 records · Page 3Linked to original sources
PubMed1990

Pharmacokinetics of lornoxicam in man.

Clinical phase I pharmacokinetic studies with lornoxicam were performed with the 4 mg dose of lornoxicam. Lornoxicam was administered as an aqueous solution both orally and intravenously to young, healthy, male volunteers. The total excretion of lornoxicam via urine and faeces after oral administration was determined by administering 14C-labelled compound. The results show that the parent compound and the main metabolite, 5'-hydroxy-lornoxicam, were found in plasma. However, in urine, no lornoxicam was detected, only 5'-hydroxy-lornoxicam. After oral as well as intravenous administration, a short terminal half-life of lornoxicam in the range of 4-5 hours was found. Given orally as solution, lornoxicam was rapidly and almost completely absorbed.

Administration, Oral↗
PubMed1990

Vinpocetine therapy does not change imipramine pharmacokinetics in man.

The influence of vinpocetine on imipramine steady-state plasma levels was investigated in 18 healthy volunteers. Twenty-five mg imipramine were given t.i.d. for a total of 21 days, vinpocetine treatment was started on day 11 with 10 mg t.i.d. and continued until the end of the study. The AUC of imipramine plasma levels were obtained using consecutive imipramine plasma level determinations from samples drawn every 2 h from 8:00 a.m. to 8:00 p.m. by trapezoidal rule. AUCs of day 10 without and of day 21 during concomitant vinpocetine treatment were compared, demonstrating the independence of imipramine's bioavailability from concomitant vinpocetine treatment. There were no indications to assume a changed absorption of imipramine due to vinpocetine as would be reflected in Cmax and tmax values. Imipramine metabolization to the still effective metabolite desipramine shows a huge interindividual variability although it remains constant for the individual. The analysis of this parameter in the course of this study does not suggest that it is changed due to vinpocetine treatment.

Adult↗
PubMed1989

[The therapeutic effectiveness of chestnut extract].

On the basis of numerous pharmacological, clinical pharmacological and clinical investigations it could be proved, that Venostasin ret., standardized on 50 mg triterpenglycosides, calculated as escine, has effects on the venous system: It has tonical effects on the veins, decreases permeability and has protective and curative properties. The mechanism of action is not fully understood, although there are some new interesting biochemical aspects regarding the attenuation of lysosomal proteoglycan destructing enzymes, which are increasingly active in patients with chronic venal insufficiency. In several double-blind randomized cross-over studies it could be demonstrated, that subjective complaints are effectively diminished. As far as objective test variables are concerned (edema), the clinical effectiveness could be shown on the basis of exact biometrical investigations. Thus the therapeutic usefulness for the treatment of chronic venal insufficiency is proven. Furthermore, regarding the good tolerability of the drug, the use of it can be recommended.

Animals↗
PubMed1988

Cardioselectivity of cetamolol compared with atenolol and nadolol.

The selectivity of the beta-adrenoceptor blockade produced by single oral doses of cetamolol, atenolol, and nadolol was compared in normal male subjects. Study 1 established the dose at which each drug provides equivalent beta-1 blockade. Beta-1 blockade was estimated using the degree of inhibition of the increased heart rate (HR) response to graded exercise. Cetamolol (30 mg), atenolol (100 mg), and nadolol (80 mg) all attenuated the HR response to a comparable extent. This result established that the dose ratio of cetamolol:atenolol:nadolol of 1.00:3.33:2.67 provides equipotent beta-1 blockade. This ratio of doses was used in Studies 2 and 3 to evaluate the antagonism of beta-2-mediated responses to titrated doses of intravenous isoproterenol (ISO) by low and high doses of each drug. Beta-2 blockade was assessed using the attenuation of ISO-induced reductions in diastolic blood pressure (DBP) in Study 2 and ISO-induced increases in specific airway conductance (sGAW) in Study 3. For within drug comparisons, antagonism of the HR increase induced by ISO (a response mediated by both beta-1 and beta-2 receptors) was also examined. Treatments included cetamolol (15 and 60 mg), atenolol (50 and 200 mg), and nadolol (40 and 160 mg in Study 2; 40 mg only in Study 3). All drugs tested suppressed the HR, DBP, and sGAW responses to ISO, and this blockade was dose dependent. Cetamolol and nadolol produced approximately equipotent beta-1 blockade, whereas cetamolol at both doses produced a less potent beta-2 blockade. Atenolol antagonized ISO effects on all parameters less than either cetamolol or nadolol. Quantitative cardioselectivity indices revealed that cetamolol 60 mg was the most cardioselective and nadolol 40 mg the least. Data from the three studies demonstrate that cetamolol is cardioselective relative to nadolol and that, in contrast to atenolol, cardioselectivity appears to increase at the higher dose.

Acetamides↗
PubMed1987

[Prazosin in the treatment of hypertension: effect on lipid metabolism].

In an open, non-comparative study, the effect of Prazosin, a selective and competitive inhibitor of alpha-adrenergic receptors, on blood pressure and lipid metabolism was studied in out-patients with hypertension. The pronounced antihypertensive effect of this vasodilator was confirmed. In almost all patients, i.e. in 144 of 171 patients with monotherapy, Prazosin caused a significant decrease of diastolic blood pressure within 3 to 6 weeks (in sitting position reduction to values below 90 mm Hg). This confirms the established antihypertensive effect due to vasodilation. In addition, Prazosin therapy is associated with a significant reduction in total cholesterol (p less than 0.001), a significant increase of HDL-cholesterol (p less than 0.001), a significant reduction of triglycerides (p less than 0.01) during the study period of 26 weeks. Prazosin monotherapy had a more pronounced influence on serum lipids than the combination of Prazosin with a diuretic. Prazosin was tolerated well; only during the first treatment weeks, a higher frequency of side effects due to abrupt reduction of blood pressure was observed, closely correlating with a too rapid increase of daily dose. Due to its proven antihypertensive effect and its favorous influence on lipid metabolism, Prazosin is suited for long-term treatment of hypertension, thus reducing two major risk factors, associated with coronary heart disease.

Blood Pressure↗
PubMed1987

Comparative pharmacokinetic analysis of latamoxef and CPW 86-363, a novel carboxy-pyrazol-cephalosporin and formation of N-methyl-thiotetrazole.

The pharmacokinetics of latamoxef and CPW 86-363, a novel carboxy-pyrazol-cephalosporin, were evaluated in healthy volunteers after intravenous bolus injection of 1 g. Based on concentration-time courses in serum both cephalosporins showed similar distribution properties, although CPW 86-363 was eliminated significantly faster. The route of elimination of latamoxef was mainly via the urine, whereas CPW 86-363 was also excreted into the bile. N-methylthiotetrazole, which is the common side chain in position 3 of both cephalosporins, was found in the serum as well as in the urine. Its rate and extent of formation was higher for latamoxef than for CPW 86-363 and depends rather on the instability of the parent compound than on metabolic transformation. This is supported by studies on the in vitro degradation of both derivatives. The relevance of these findings are discussed in view of secondary coagulopathies, which are associated with cephalosporins having a N-methylthiotetrazole side chain.

Adult↗
PubMed1986

Pharmacokinetic profile of imidazole 2-hydroxybenzoate, a novel nonsteroidal antiinflammatory agent.

Imidazole 2-hydroxybenzoate is a novel nonsteroidal antiinflammatory agent which clinico-pharmacologically and pharmacokinetically has to be understood as imidazole and salicylic acid. The pharmacokinetic profile of both components after single and multiple oral (tablets, drops), and topical administration (gel 5%)--the latter in a pilot study--was evaluated as well as protein-binding, relative bioavailability and the metabolic pattern. Absorption and elimination of the two compounds were fast. All essential pharmacokinetic and bioavailability parameters seem to be in a good agreement with data published in the literature and an accumulation tendency was not observed. The t1/2 beta for imidazole (oral administration) was determined for a single dose at 2.98 +/- 1.13 h, for a multiple dose (last dose) at 1.86 +/- 0.78 h; for salicylic acid the t1/2 beta for a single dose was determined at 6.46 +/- 3.79 h and for a multiple dose (last dose) at 6.40 +/- 3.36 h. The protein-binding of imidazole was in the range of 5-15% and of salicylic acid of about 80-85%. The relative bioavailability was calculated for imidazole (single dose) at 138% and for multiple dosing (last dose) at 113%; for salicylic acid the values for single dose were 148% and for multiple dosing (last dose) 128%. The tolerability was altogether good and no adverse reactions could be observed. The topical administration (pilot study) with gel 5% did not show any systemic effects or adverse reactions. The local tolerability was very good. Statistically, there were only slight differences between tablets and drops overall since only one p-value was less than 0.01. According to the small sum of squared residuals, the NONLIN-program performed an excellent fitting of the data to the model equation.

Administration, Cutaneous↗
PubMed1985

[Open study on the effect and side effects of indoramin, used at the 2d and 3d therapeutic step in essential hypertension].

An open study was undertaken to investigate the efficacy and adverse effects of indoramin in 33 patients with essential hypertension whose blood pressure was uncontrolled (diastolic blood pressure 96 to 115 mm Hg) despite previous treatment with one or two antihypertensive drugs. Indoramin was added to the existing antihypertensive therapy and the dose titrated to a maximum of 150 mg/day or until blood pressure control was achieved (diastolic blood pressure less than 90 mm Hg or a reduction in diastolic blood pressure of 15 mm Hg). Patients were then followed up for a further 4 weeks. Indoramin significantly reduced mean standing systolic and diastolic blood pressure from 167/113 +/- 19.8/7.2 (SD) mm Hg to 150.3/101.1 +/- 23.4/8.9 (SD) mm Hg after 10 weeks and mean supine systolic and diastolic blood pressure from 169.8/110.8 +/- 16.4/5.6 (SD) mm Hg to 154.2/102.1 +/- 23.8/12 (SD) mm Hg after 10 weeks. Blood pressure was controlled in 21 of the 33 patients (63.6%) studied. Indoramin caused a small but significant fall in pulse rate of 3.9 beats per minute, in the supine position, after 4 weeks therapy. 10 patients experienced adverse effects, the most common being dizziness and headache (3 patients each), and lightheadedness/fainting on standing (2 patients). No patient experienced sedation. Only 1 patient was withdrawn from the trial because of adverse effects (fainting on standing). Biochemical and haematological investigations carried out pretreatment and during treatment showed no abnormalities related to indoramin treatment.

Adult↗
PubMed1985

[Treatment of medium-severe essential hypertension with beta-Aldopur under practice conditions].

23 hypertensive patients were treated with the new fixed-dose combination drug Beta-Aldopur, containing 100 mg bupranolol and 50 mg spironolactone per tablet. In part they had been pretreated with other fixed combinations without sufficient success. 19 patients completed the eight-week study. Initial dosage of two tablets could be reduced to one tablet daily following normalization (less than 90 mm Hg) of diastolic blood pressure in one third of patients. Mean pressure in a sitting posture was lowered from 176 +/- 21/111 +/- 9 mm Hg to 156 +/- 21/93 +/- 8 mm Hg (p less than 0,0001) gradually until the 4th week. Body weight decreased by 2.5 kg (3.1%) until the 6th week and remained constant thereafter. Mean concentration of serum potassium rose significantly by 0.42 mmol/l within normal limits. Specific and non-specific side effects were very rare and no serious reactions occurred. Compared to pretreatment with other fixed combinations, most of them containing thiazides, the combination of bupranolol with spironolactone was more efficacious in lowering the blood pressure. According to the results of our study Beta-Aldopur is suitable for treatment of essential hypertension of all degrees, especially for patients prone to hypokalemia, if secondary aldosteronism caused by hypertension or by medication may be expected and/or if other medications are not adequately effective.

Antihypertensive Agents↗
PubMed1984

Pharmacokinetic pilot study with imidazole 2-hydroxybenzoate using new analytical methods.

Imidazole 2-hydroxybenzoate is a new antiphlogistic compound with analgesic and antipyretic properties undergoing clinical investigations. The purpose of this pilot study was to evaluate new methods for the quantitation of imidazole, salicylic acid and salicyluric acid in plasma and urine. Imidazole metabolites caused considerable methodologic difficulties in plasma and urine. They were below the detectable limit. Salicylic acid metabolites were present in plasma also under the limit of detection (0.5 microgram/ml). In urine the metabolite salicyluric acid was measured in considerable quantities, whereas gentisinic acid was under the limit of detection. Three healthy volunteers were given a single p.o. dose of 750 mg imidazole 2-hydroxybenzoate in order to examine the practicability of these new methods a well as to evaluate the pharmacokinetics. The data are presented and interpreted. Further studies in this respect are advised.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1984

Comparison of gastrointestinal blood loss induced by cloximate in two formulations and by naproxen.

In a double-blind baseline controlled crossover trial gastrointestinal blood loss induced by cloximate in two different formulations (enteric-coated and non-enteric coated) was compared with naproxen. Gastrointestinal blood loss increased more in the naproxen group (0.41 ml/24 h) than in the group treated with non-enteric coated cloximate. The group treated with coated cloximate had a higher mean increase in gastrointestinal blood loss (0.36 ml/24 h) compared with placebo than those treated with non-coated cloximate.

Acetates↗
PubMed1983

[Drug interactions as a cause for iatrogenic diseases in the aged. A tabulated presentation].

Drug interactions are found in elderly patients to a higher degree than in younger persons, because of the multimorbidity in the advanced age. The reasons are pharmacokinetic and/or pharmacodynamic mechanisms. At the first glance the amount of interactions seems puzzling but after regarding details more thoroughly it turns out that most of those interactions may be attributed to just a few drugs.

Aged↗
PubMed1982

[Controlled randomized double-blind study for the comparison of the treatment of patients with essential hypertension with homeopathic and with pharmacologically effective drugs].

In a randomized double-blind cross-over study the effects of antihypertensive pharmacotherapy were compared with those of homeopathic treatment in 10 patients with essential hypertension. The conclusions are: 1. The blood pressure lowering effect under pharmacotherapy is clearly superior to that under homeotherapy, where it was negligible and statistically not significant. 2. As far as improvement of subjective complaints of the patients is concerned there was no superiority of pharmacotherapy over homeopathic treatment. 3. The cross-over design appears less suitable than, perhaps, a design with parallel treatment groups because of the long duration of such a study and the observed carry-over effect.

Amiloride↗