Efficiency and mechanisms of the antioxidant effect of standard therapy and refracterin in the treatment of chronic heart failure in elderly patients with postinfarction cardiosclerosis.

Refracterin therapy of patients with chronic heart failure caused by coronary heart disease and postinfarction cardiosclerosis markedly promoted improvement in the pulmonary and systemic circulation in comparison with patients receiving traditional therapy. The mean functional class of chronic cardiac failure decreased by 43% under the effect of refracterin vs. 27% decrease in the group receiving traditional therapy. After 1-month refracterin course the end-systolic and end-diastolic sizes of the left ventricle decreased by 12 and 7%, respectively, ejection fraction increased by 7.2% in comparison with the initial level, total oxidant activity and MDA content in the plasma decreased significantly, while total antioxidant activity, catalase and SOD activities, cytochrome C, NADH, and NADPH levels increased. The prooxidant-antioxidant system was shifted towards antioxidants, which attests to activation of the defense and adaptive mechanisms after administration of refracterin, which is especially important in elderly patients with initially decreased reserve potentialities of the antioxidant defense system.

[Absolute bioavailability of beta-acetyldigoxin from tablets and drops in healthy subjects]. / Absolute Bioverfügbarkeit von beta-Acetyldigoxin aus Tabletten und Tropfen bei gesunden Probanden.

In a crossover design in random order 12 healthy male volunteers were given either beta-acetyldigoxin (Novodigal, CAS 5511-98-8) tablets, oral solution or i.v. application at a digoxin equivalent dose of 0.284 mg. To reach steady state each preparation was given for 10 days on a once-daily schedule. On days 8, 9 and 10 of each observation period blood was sampled to determine trough concentrations of digoxin in steady state. In addition, on day 10 blood was collected repeatedly at appropriate time intervals and urine was sampled concomitantly for 24 h. Trough values during steady state and 24 h AUC were used to calculate digoxin bioavailability for tablets and oral solution. From trough values, the mean bioavailability for beta-acetyldigoxin tablets was 91.2% (range 73.1-118.1) and for solution 93.8% (range 65.7-114.8). Using the AUCs 0-24 h at steady state bioavailability was calculated 77.7% for the tablets and 84.5% for the solution. Since trough values in steady state represent the body burden of digoxin which is supposed responsible for the therapeutic effect, trough values should be given priority for the determination of digoxin bioavailability from beta-acetyldigoxin tablets and solution. All formulations were well tolerated. No clinically relevant side effects were observed.

Pharmacokinetics of pengitoxin and its therapeutic efficacy in congestive heart failure.

In a therapeutic study, 120 inpatients suffering from congestive heart failure were treated with a daily maintenance dose of 0.3 mg pengitoxin (penta-acetyl-gitoxin) over several weeks or months. The plasma level and the glycoside concentration in urine were measured by radioimmunoassay. The therapeutic effects were evaluated considering clinical signs and criteria following the functional capacity according to the New York Heart Association (NYHA). In 27 patients both plasma and urine concentration were measured during 2 weeks after the beginning of the pengitoxin therapy. On the 3rd day of the pengitoxin dosage schedule, a mean plasma level of 18.1 ng.ml-1 (SD 5.1 ng.ml-1) was measured. During this day 26.6% of the daily administered glycoside dose was excreted in urine. In 26 of the 120 patients the mean steady state plasma level was between 7.6 and 22.5 ng.ml-1. A maximum of frequency was found in the 17.6 to 22.5 ng-subclass. In 118 patients the mean urinary excretion of 16-acetyl-gitoxin reached 24.7% (SD 11.8%) of the administered dose. The creatinine clearance and the 16-acetyl-gitoxin plasma level did not correlate, while between the renal clearance values of creatinine and the glycoside a correlation was found, however, it was of no significance for dosage schedules in patients with impaired renal function. After treatment, the NYHA classes III and II were reached in 57 patients; in 3 patients suffering from renal diseases, the NYHA class I remained unchanged. In 90 patients the clinical signs improved and in 27 patients the clinical situation remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

On the pharmacokinetics of 16-acetyl-gitoxin and its bioavailability from pengitoxin-containing tablet formulations.

In six volunteers the pharmacokinetics of 16-acetyl-gitoxin (16AG, 0.5 mg) administered intravenously (A1) and as an oral solution (A2) and of pengitoxin (PAG, 0.6 mg) administered intravenously (A3) was evaluated. In six volunteers the bioavailability of 16AG from two PAG tablet formulations (1.2 mg) (B2, B3) was measured by comparison with the absorption after administration of a pengitoxin solution (1.2 mg) (B1). In both studies the test was performed using a crossover design. After a single i.v. injection of equimolar doses, 16AG and PAG showed similar mean kinetic parameters: t1/2 = 51.6 hr (16AG) and 60.8 hr (PAG), CL = 11.7 ml min-1 (16AG) and 12.7 ml min-1 (PAG), CLR = 4.1 ml min-1 (16AG) and 4.2 ml min-1 (PAG). The 16AG was absorbed from solution with a mean half-life of 0.2 hr to an extent of 98.6%. The mean urinary excretion/Ae (0,4)/of 16AG amounted to 24.6% (A1), 20.8% (A2) and 28.1% (A3). On the basis of AUC values, the mean bioavailability of PAG from either tablet formulation amounted to 79.6% (B2) and 89.6% (B3). The pharmacokinetic parameters of 16AG (PAG) are closer to those of digitoxin than those of digoxin. In general, 16AG is characterized as a digitoxin with a digoxin-like elimination half-life.

[Interaction of isoxicam and digoxin]. / Untersuchungen zur Wechselwirkung von Isoxicam und Digoxin.

The influence of maintenance therapy with Isoxicam, 200 mg daily, on digoxin steady-state plasma levels was studied on 12 healthy volunteers. One person dropped out from the investigation program on account of cardiac sensations following the invasion phase with digoxin. No statistically significant differences could be shown during concomitant therapy or after withdrawal of Isoxicam. Neither were toxic glycoside plasma concentrations observed. There were no pathological clinicochemical parameters, in particular no changes in renal function values.

[Epidemiology of digitalis medication. Results of the Munich blood-pressure study]. / Zur Epidemiologie der Digitalismedikation. Ergebnisse der Münchner Blutdruckstudie.

As part of a blood-pressure survey in Munich, some of its inhabitants aged 30-69 years were asked by questionnaire about any digitalis medication. Chemically defined glycosides were taken by 127 of 1827 persons (7%), two-thirds of them older than 60 years, for clinically compensated chronic heart failure. Using the equation of Cockcroft and Gault to calculate creatinine clearance, it was below 80 ml/min and thus indicative of early impairment of renal function in more than 50%. In 44% the prescribed daily dose of glycoside corresponded to the calculated maintenance dose, 29% had less and 27% had taken more. None had clinical signs of digitalis intoxication. ECG changes possibly due to digitalis were much less common than had been expected. Sinus rhythm was present in 93%. More than 50% did not know why they were taking digitalis and 80% were taking two or more drugs at the same time. Since more than half had signs of early renal function impairment, creatinine clearance should be taken into account when determining the dosage of a digoxin preparation especially in elderly patients; alternatively, digitoxin should be prescribed. The survey also showed that a large number of persons on glycoside medication did not take the drug regularly.

Effects of cytostatic drugs on plasma level and renal excretion of beta-acetyldigoxin.

Mucosal defects decrease digoxin absorption in patients with malabsorption syndromes. Since the intestinal mucosa can be damaged by cytostatic drugs, we investigated their effects on digoxin plasma levels and urinary digoxin excretion. In six patients with malignant lymphoma who received 0.8 mg beta-acetyldigoxin before and 24 hr after treatment with a combination of cyclophosphamide, oncovin, procarbazine, and prednisone (COPP) or cyclophosphamide, oncovin, and prednisone (COP), plasma digoxin concentrations were measured 0 to 8 hr after the dose and areas under the plasma concentration-time curves were calculated. In 15 patients on 0.3 mg of beta-acetyldigoxin daily, plasma glycoside concentrations and renal excretion were measured daily before and after COPP, COP, cyclophosphamide, oncovin, cytosine-arabinosine, and prednisone (COAP), or adriamycin, bleomycin, and prednisone (ABP) treatment schemes. The diminished steady-state glycoside plasma concentrations and daily renal glycoside excretion during the 24 to 168 hr after the cytostatic drug established reversible impairment of digoxin absorption. The delayed time to peak after a single dose of digoxin during cytostatic drug therapy shows that extent and rate of digoxin absorption are reduced. To maintain adequate control of digoxin therapy in patients treated with cytostatic drugs, plasma levels should be monitored.