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Biomedical subjects

W Kirch

Publications and source records attributed to W Kirch.

At least 235 records · Page 13Linked to original sources
PubMed1986

Interaction of bisoprolol with cimetidine and rifampicin.

In 6 healthy volunteers the pharmacokinetics of bisoprolol under steady-state conditions was investigated over three consecutive phases: over 7 days of 10 mg of bisoprolol once daily per os, 7 days of 10 mg of bisoprolol once daily plus 400 mg of cimetidine t.i.d. and 14 days of 10 mg of bisoprolol and 600 mg of rifampicin once daily with adequate intervals free of medication. After therapy with bisoprolol alone peak plasma levels (Cssmax) of the beta-blocker were 55.5 +/- 6.4 ng/ml (means +/- SEM), area under the plasma level-time curve (AUC tau) was 597 +/- 70 ng/ml.h, total body clearance (CL) 15.8 +/- 1.8 l/h and elimination half-lives (t1/2 beta) 10.1 +/- 1.2 h. Cimetidine did not cause any significant changes in the pharmacokinetics of bisoprolol. Co-administration of rifampicin resulted in a decrease in Cssmax (43.0 +/- 6.9 ng/ml), AUC tau (397 +/- 54 ng/ml X h) and t1/2 beta (6.2 +/- 0.4 h). Accordingly, total body clearance increased to 23.8 +/- 2.5 l/h (p less than 0.05). In conclusion bisoprolol showed a statistically significant but probably clinically not important interaction with the enzyme-inducing drug rifampicin, but not with the enzyme inhibitor cimetidine.

Adrenergic beta-Antagonists↗
PubMed1986

Bioavailability and elimination of digitoxin in patients with hepatorenal insufficiency.

Following administration of digitoxin, 1 mg intravenously, the pharmacokinetics of this glycoside were studied in eight healthy volunteers and in eight patients with hepatorenal insufficiency (mean creatinine clearance 19.6 +/- 2.9 ml/min; antipyrine clearance 25.6 +/- 3.2 ml/min; means +/- SEM). Liver cirrhosis of the patients was confirmed by liver biopsy. Plasma protein binding of digitoxin (means +/- SEM) was 95.1 +/- 0.7% in the patients and 95.6 +/- 1.2% in the volunteers (NS). Total body clearance of digitoxin was 0.0530 +/- 0.0040 ml/min/kg of body weight in the patients and 0.0547 +/- 0.0043 ml/min/kg of body weight in the healthy subjects (NS). When elimination half-lives of the patients and the volunteers were compared, there was also no significant difference (7.0 +/- 0.77 days in the patient group and 7.8 +/- 0.8 days in the volunteers). Our data concerning digitoxin kinetics in patients with hepatorenal insufficiency do not indicate an accumulation of the drug in these patients.

Adult↗
PubMed1986

Dose-dependence of the nifedipine-digoxin interaction?

The dose-dependence of the nifedipine-digoxin interaction was investigated in seven healthy subjects. After an adequate loading dose of digoxin for 2 weeks, 0.25 mg digoxin b.i.d. was given by mouth by itself. Afterwards, 0.25 mg digoxin was given twice a day for three 1-week periods in combination with capsules of nifedipine, 5, 10, or 20 mg, respectively, given on a thrice-daily basis. The study ended with a digoxin monotherapy phase lasting 7 days. All three doses of nifedipine significantly increased digoxin plasma concentrations and AUC compared with digoxin monotherapy. Thus, for example, the AUC was 10.16 +/- 0.88 ng/ml . hr (mean +/- SE) when digoxin was given alone and 12.33 +/- 1.59 ng/ml . hr with concurrent nifedipine, 5 mg t.i.d. (P less than 0.05). Nifedipine causes a slight but significant increase (15%) in digoxin plasma concentrations and AUC. This effect did not depend on the nifedipine dose given in the range studied.

Administration, Oral↗
PubMed1986

Influence of nisoldipine on haemodynamic effects and plasma levels of digoxin.

In a placebo controlled double-blind study including 10 patients with heart failure the nisoldipine/digoxin interaction was studied. Nisoldipine was shown to elevate digoxin plasma concentrations significantly by about 15% (trough levels). During chronic combination therapy with nisoldipine trough levels and plasma concentrations 4 h after the morning dose of digoxin were 1.35 +/- 0.14 and 1.92 +/- 0.16 ng ml-1 respectively, whereas they averaged to 1.16 +/- 0.14 and 1.52 +/- 0.16 ng ml-1 with digoxin and placebo (P less than 0.05; mean +/- s.e. mean). Systolic time intervals were significantly altered by nisoldipine co-administration compared with digoxin plus placebo. In certain patients the elevation of digoxin plasma levels due to nisoldipine co-administration could be of clinical relevance.

Adult↗
PubMed1986

Double-blind comparison of ketanserin with atenolol: antihypertensive activity and effect on platelet function.

In a randomized double-blind study with parallel design involving 20 hypertensive patients, the antihypertensive activity and effect on platelet function of ketanserin have been compared with those of atenolol. Patients in both treatment groups were matched for age, body weight, duration of hypertension and blood pressure values on placebo. After 12 weeks of oral treatment, both ketanserin and atenolol significantly reduced blood pressure from 183/113 and 187/111 mmHg, at the end of the placebo run-in period, to 159/91 and 169/99 mmHg, respectively (P less than 0.05). No significant differences were noted between the hypotensive effect of both drugs. In contrast to ketanserin, atenolol significantly reduced the heart rate after 12 weeks of therapy (P = 0.025). Ketanserin significantly inhibited serotonin-induced platelet aggregation and serotonin uptake by thrombocytes, whereas atenolol failed to alter these variables. The results indicate that the antihypertensive activity of the serotonin antagonist ketanserin is comparable with that of the beta-receptor blocker atenolol.

Adult↗
PubMed1986

In vivo activated peripheral T cells in autoimmune disease.

Starting from the observation, if that in patients suffering from inflammatory bowel diseases elevated numbers of activated peripheral immunocytes can be detected in correlation to the activity of the disease, subpopulations of lymphocytes in immune-mediated disorders were analyzed for the expression of activation associated antigens. It was found that in patients with immunovasculitis, sarcoidosis, M. Behçet, multiple sclerosis, antibody-mediated hemophilia, SLE,--but not in those with scleroderma--, increased numbers of activated immunocytes could be detected during acute exacerbation, whereas, in remission, the population of activated immunocytes was in the upper normal range. Analyses of phenotypes revealed that the majority of activated immunocytes are T cells. However, a variable minority of cells bear B cell associated determinants. As is the case in total peripheral T cells, the T4 to T8 ratio was in a normal range. Only in Behçet disease and immunovasculitis was the ratio of activated T4 positive to activated T8 positive lymphocytes found to be decreased. In contrast to T cells in patients with inflammatory bowel disease, the majority of activated T cells in the autoimmune disorders under study does not express Fc alpha-receptors. In Behçet disease and immunovasculitis moreover, the incidence of activated Leu 7 positive (= natural killer) cells is low compared to T cells from patients with Crohn's disease or ulcerative colitis. These experiments lead to the conclusion that the assessment of activated immunocytes may serve as a parameter in the evaluation of the clinical activity of autoimmune diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1986

[Follow-up of immunological parameters and therapy of systemic lupus erythematosus].

In a longitudinal study of a female patient with systemic lupus erythematosus, we determined numbers of T-lymphocytes and subpopulations (OKT4+- and OKT8+-lymphocytes), B-lymphocytes, production of anti-double-stranded DNA antibody (anti-ds-DNA-Ab), and we investigated the effects of corticosteroids and cyclophosphamide on these parameters and clinical disease activity. The results demonstrate that an increase of OKT4+-T-lymphocytes/OKT8+-T-lymphocytes ratio apparently augments B-lymphocyte numbers resulting in anti-ds-DNA-Ab production. Whereas steroids exerted limited, possibly dose-dependent effects on this sequence, cyclophosphamide seemed to cause normalization of OKT4+/OKT8+ ratio, precipitous drop of anti-ds-DNA-Ab titers, and dramatic clinical improvement.

Adrenal Cortex Hormones↗
PubMed1986

Pharmacokinetics of salicylates administered with metoprolol.

The widely used acetylsalicylic acid (ASA, Colfarit) was administered in combination with metoprolol (Lopresor) during 7 days. Plasma concentrations of total salicylates (ASA and salicylic acid (SA) and metoprolol were monitored during the treatment period, on day 7 urinary excretion was also investigated. The kinetic data of the compounds were compared to those of the metoprolol and ASA control periods. Metoprolol kinetics remained uninfluenced whereas the maximal plasma concentrations of the salicylates were significantly higher than in the ASA control period.

Adult↗
PubMed1985

[A trichlormethiazide-amiloride combination in essential hypertension].

Following a placebo period of 2 weeks 39 patients with essential hypertension were given during 4 weeks a combination of 2 mg trichlormethiazide and 2 mg amiloride (Esmalorid). If the blood pressure was adequately reduced treatment was continued for a further 4 weeks; if not, a double dose was dispensed during the second 4-week period. Patients with a diastolic blood pressure under 90 mm Hg after 8 weeks when treated with a 1 mg dose, were subsequently treated with a 1 mg dose for a period of 3 months. After 8 weeks of treatment mean systolic blood pressure was reduced from 167 +/- 17 mm Hg to 151 +/- 19 mm Hg (sitting) and from 163 +/- 15 mm Hg to 148 +/- 18 mm Hg (standing), while mean diastolic blood pressure was decreased from 104 +/- 6 mm Hg to 93 +/- 8 mm Hg (sitting) and from 105 +/- 6 mm Hg to 94 +/- 8 mm Hg (standing). In 29 patients diastolic blood pressure had dropped to values under 95 mm Hg. Serum potassium remained constant during the treatment except for three patients with values outside the normal range (3.3, 3.4 and 5.2 mmol/l). The other serum electrolytes, glucose, creatinine, blood lipids, transaminases, hemogram, as well as body weight and heart rate remained unchanged. Two patients complained of side effects and did not complete the study. All other patients tolerated the treatment well.

Adult↗
PubMed1985

Cyclophosphamide-induced remission in Weber-Christian panniculitis.

A patient with Weber-Christian panniculitis is described in this report in which treatment with prednisone and hydroxychloroquine caused no improvement of the disease, and even led to a worsening of the symptoms. In contrast, administration of oral cyclophosphamide led to a rapid remission of the disease. As Weber-Christian disease has no known aetiology and no specific treatment has been established, the successful therapy with the cytostatic drug cyclophosphamide may shed light on the pathogenesis of Weber-Christian panniculitis.

Adult↗