Biomedical subjects

G Hitzenberger

Publications and source records attributed to G Hitzenberger.

At least 19 recordsLinked to original sources

PubMed1992

[Primary and secondary prevention in hypertensive patients. An assessment of current status].

The effect of a long-term treatment with beta-receptor-antagonists after an established myocardial infarction is generally accepted. Beta-receptor-antagonists without intrinsic sympathicomimetic activity should be used, cardioselectivity is of lesser importance, except in patients with special problems (i.e. increased bronchial resistance, decreased peripheral blood flow etc.). Hydrophilic or lipophilic properties do not play any role. For primary prophylaxis in older hypertensives diuretics are the drugs of first line, in patients with high risk for heart- and blood-vessel diseases however beta-receptor-antagonists--eventually in combination with low doses of diuretics-should be chosen.

Adrenergic beta-Antagonists↗

PubMed1992

[The effect of ginkgo biloba special extract (EGb 761, Tebofortan)].

Ginkgo biloba special extract exerts positive effects on hemorheology and platelet aggregation, is a free radical scavenger and possesses PAD antagonistic properties, protects against hypoxia and ischemia, hampers an experimentally induced cerebral edema, has favourable properties on neurotransmitters and enhances cerebral bloodflow. Clinically EGb has proven favourable effects on intellectual deficiency, equilibrium disturbances and peripheral artery occlusions thus being a drug with a clear cut indication for these diseases.

Animals↗

PubMed1991

Antihypertensive effects of isradipine and captopril as monotherapy or in combination.

The antihypertensive effects of isradipine and captopril were studied in 140 patients (70 men) with mild-to-moderate hypertension, aged 26 to 74 years, in a double-blind, randomized, between-patient comparative trial. Initial treatment started with 1.25 mg isradipine twice daily or 12.5 mg captopril twice daily. If normotension was not achieved after four weeks, doses were increased to 2.5 mg twice daily or 25 mg twice daily, respectively. If the maximum dose as monotherapy did not result in normotension, captopril (12.5 mg or, if necessary, 25 mg twice daily) was added to regimens of the isradipine-treated patients or isradipine (1.25 mg or, if necessary, 2.5 mg twice daily) was given in addition to the captopril-treated patients. After 24 weeks of active treatment, systolic blood pressure was significantly reduced (P less than .001) with isradipine (from 168 +/- 18 to 144 +/- 14 mm Hg) and with captopril (from 168 +/- 20 to 143 +/- 10 mm Hg). Diastolic blood pressure also fell significantly (P less than .001) in both groups (isradipine: from 105 +/- 5 to 84 +/- 5 mm Hg; captopril; from 105 +/- 4 to 85 +/- 4 mm Hg). With isradipine as monotherapy, diastolic blood pressure was normalized in 49% of patients compared with 56% with captopril as monotherapy (P = NS). Combining both drugs resulted in an increased rate of normalization (to 87%). The results indicate that combined treatment with a calcium antagonist and an angiotensin-converting enzyme inhibitor is effective in lowering blood pressure and is well tolerated during long-term therapy.

Adult↗

PubMed1991

Evaluation of isradipine and captopril alone or in combination for the treatment of hypertension.

The antihypertensive effects of isradipine and captopril were studied in 231 patients with mild-to-moderate hypertension in a double-blind, randomized, between-patient trial. Treatment was started with 1.25 mg of isradipine or 12.5 mg of captopril twice daily which, if normotension was not obtained, was increased after 4 weeks to 2.5 mg or 25 mg twice daily, respectively. If the maximum dose of each drug alone did not result in normotension, captopril (12.5 mg or, if necessary, 25 mg twice daily) was added to the isradipine regimen, and isradipine (1.25 mg or, if necessary, 2.5 mg twice daily) to the captopril regimen. Following 24 weeks of active treatment, systolic blood pressure (SBP) was significantly (p less than 0.001) reduced by isradipine (170 +/- 17 vs. 153 +/- 17 mm Hg) and by captopril (170 +/- 19 vs. 155 +/- 19 mm Hg). Diastolic blood pressure (DBP) also fell significantly (p less than 0.001) in both groups (isradipine: 106 +/- 5 vs. 93 +/- 8 mm Hg; captopril: 106 +/- 5 vs. 95 +/- 10 mm Hg). After isradipine as monotherapy, DBP was normalized in 49% of patients compared with 52% after captopril monotherapy. Combination of both drugs increased the normalization rate to 84%. The results indicate that combined treatment with a calcium antagonist and an angiotensin-converting enzyme (ACE) inhibitor is effective in lowering blood pressure, and is well tolerated as long-term therapy.

Adult↗

PubMed1990

[Clinical pharmacology of ACE inhibitors].

The main effect of the ACE-inhibitors is a reduction of the peripheral resistance and according to that an increase of blood-flow to the organs. Direct effects on the heart are of minor importance. The exact mechanism of action is not fully understood; the main role plays obviously the inhibition of the angiotensin converting enzyme itself; in addition may be effects on the kallikrein-bradykinin-prostaglandin-system are of importance. The pharmacodynamical effects depend on the plasma-concentration and therefore on the pharmacokinetics. These are different with Captopril and Enalapril: Captopril acts directly whereas Enalapril is a "prodrug". With the nowadays used doses Captopril and Enalapril are widely free of side-effects. With the exception of patients with negative sodium-balance (salt-poor diet and/or treatment with diuretics) or patients with renal insufficiency (sometimes increase of creatinine and potassium). In the first group of patients the first dose of ACE-inhibitors should be administered in the evening before going to bed, in the second group creatinine and potassium must be checked 5 to 7 days after an initiation of treatment.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1990

Influence of vinpocetine on warfarin-induced inhibition of coagulation.

The influence of 14 days of concomitant vinpocetine administration on prothrombin time prolongation of single 25 mg doses of warfarin was investigated. Eighteen male subjects were included in the study. They received 25 mg warfarin the first day. Prothrombin time, warfarin plasma levels and factor VII coagulation time were monitored on days 1-5. Ten mg vinpocetine was administered from day 6 to 24. Another single dose of 25 mg of warfarin was given a second time on day 20. AUC values of prothrombin time, warfarin plasma level and factor VII clotting time curves and appropriate Cmax and tmax plasma levels of days 20-24 were compared with those of days 1-5. The confidence interval limits of the ratio of AUC20-24/AUC1-5 of prothrombin time curves were within the limits of 0.8 and 1.2, so that the formal criteria of equivalent biological activity were met. However, a minute influence probably without clinical implication is likely since both point estimate as well as confidence interval limits were below 1.

Adolescent↗

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