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At least 523 records · Page 29Linked to original sources
PubMed1978

Plasma concentrations of isosorbide dinitrate after administration of increasing doses of a sustained-release formulation to human subjects.

Plasma concentrations of isosorbide dinitrate have been measured after administration of increasing doses in the range 20--100 mg as sustained-release tablets (Isoket retard) containing 20 mg to human subjects. Means of peak concentrations of 4.2 ng/ml, 13.1 ng/ml, 20.7 ng/ml, 36.8 ng/ml, and 34.9 ng/ml were measured after doses of 20 mg, 40 mg, 60 mg, 80 mg and 100 mg, respectively. In the plasma of individual subjects, peak concentrations of isosorbide dinitrate increased in proportion to the dose administered. Areas under the plasma isosorbide dinitrate concentration-time curves also increased in proportion to the dose administered. Bioavailability parameters were better correlated to the dose over the range 20--60 mg than over the range 20--100 mg.

Adult↗
PubMed1979

[Plasma levels, renal excretion and metabolism of orciprenaline after administration in sustained-release form (author's transl)].

A newly developed sustained-release form of orciprenaline-sulfate (Alupent) was tested in 13 patients. Determination of 3H-radioactivity in blood, urine and faeces was used to elucidate its pharmacokinetic properties. Maximum plasma levels of radioactivity were obtained between 8 and 12 h after administration. 10.7 +/- 2.5% of the administered radioactivity were excreted in urine over a period of 72 h. Orciprenaline was mainly excreted as the sulfate-conjugate. Approximately five percent of the radioactivity were excreted as 4,6,8-trihydroxy-N-isopropyl-tetrahydroisoquinoline--the condensation product of formaldehyde and orciprenaline.

Biotransformation↗
PubMed1978

[Relative bioavailability of a vincamine retard formulation. Pharmacokinetic study in normal subjects (author's transl)].

The study was carried out in 6 healthy volunteers in cross-over design. The pharmacokinetic parameters were calculated after application of 60 mg vincamine base in comparison to a sustained release formulation (vincamine ratio-pharm 30 mg) on the basis of a GC method. Summarizing it can be stated that the sustained release formulation has a flatter profile and is therefore more adapted to clinical application. The extent of absorption expressed as AUC of the serum concentration-time curve, has three times the extent of the curve with the pure substance.

Biological Availability↗
PubMed1976

Quinidine syncope: torsade de pointes with low quinidine plasma concentrations.

In 2 patients without clinically significant ischemic heart diseases, oral quinidine was used to control supraventricular arrhythmias. In both patients, syncopal attacks occurred, caused by a particular type of ventricular tachyarrhythmia called torsades de pointes. Quinidine plasma concentrations were low (2.6 and 1.2 mg/1, respectively); QRS duration was normal, but the Q-T interval was markedly prolonged.

Aged↗
PubMed1975

[Zollinger-Ellison syndrome treated medically by an inhibitor of H2 histamine receptors].

Metiamide an histamine H2-receptors antagonist has been used to treat a case of Zollinger-Ellison syndrome characterized by a long standing diarrhea, an important gastric hypersecretion and a moderatly elevated plasma gastrin but without digestive ulceration. At the dose of 600 mg per day, Metiamide induced a complete suppression of acid secretion, an effect which lasted for 15 days after stopping the drug. Accordingly and since the only finding at time of laparotomy was a small lymph node enlarged with endocrine metastatic tissue, the stomach was left intact and Metiamide pursued. During the first 4 months of chronic administration of Metiamide, acid secretion was maintained at levels below 25 p.cent of initial values. Ulteriorly however, although dosages of Metiamide were increased, acid hypersecretion resumed and a duodenal ulcer developed. Total gastrectomy was then performed 11 months after the beginning of Metiamide. In spite of the failure of Metiamide treatment, the long term follow up of this case of Zollinger-Ellison Syndrome, allowed us to get theoretical and practical informations.

Adult↗
PubMed1976

[Drug-drug interactions (author's transl)].

This short outline of drug-drug interactions does not claim to cover the entire field. The task of this paper is to illustrate the most important principles of drug-drug interactions by paradigms taken from the experience of the practitioner. One consequence of drug-drug interactions is the change in pharmacolinetic parameters important for the therapeutical effect of drugs in the organism. Very often the elucidation of the mechanisms of drug-drug interactions in man is impossible; therefore, for clinical pharmacologists experiments on animals remain the tool in order to gain more knowledge in this field.

Age Factors↗
PubMed1976

[Galenical possibilities and problems in protraction of drug effects (author's transl)].

In recent years, dosage forms with sustained release have obtained a significant importance. The technological possibilities for manufacturing are described as coating, embedding and matrix procedures. The range of auxiliary substances, which are responsible for the retardation of drug activity, reaches from lipophilic compounds as lipoids, fatty alcohols and compounds which are forming hydrogels as cellulose derivatives and natural polysaccharides to synthetic polymers derived from acrylic acid. The formulation of the dosage forms requires particular care in respect to the amount of initial and maintenance doses. On account of technological processes, for example during manufacturing of tablets, under certain circumstances the liberation rate is altered. In vitro test methods allow comparisons only then when the results can be counter-checked by in vitro experiments. The release of drug follows different mechanisms, which are described, entirely or in part, to be reactions following the time law of zero or first order. In special cases, a linear correlation is observed as a function of square root of time. The calculation of given special equations for events within the dosage form is feasible from blood-level values.

Biological Availability↗
PubMed1976

[The influence of neuroleptic drugs on urinary excretion of non-protein nitrogen (author's transl)].

During treatment with thioxanthenes or phenothiazines of schizophrenic patients non-protein nitrogen in urine was measured. The values were calculated in relation to the excretion of creatinine. a) Flupentixol or fluphenazine applied in optimal dosage, increased the excretion of urea and the amino acids asp, glu + gln, and gly. b) Moreover, if the drug induced a parkinsonoid (thioridazine) the excretion of ser and thr was increased, too. The usual desalting procedure by ion-exchanging resins before chromatography increases the contents of several amino acids, e.g. asp, asn, ala, gly, cys, ser, thr, indicating a breakdown of some instable products.

Amino Acids↗