medigoxin and Atrial-Fibrillation

Topics: Adult; Aged; Atrial Fibrillation; Digoxin; Female; Humans; Male; Medigoxin; Middle Aged

1 Medigoxin (Lanitop) 300 microgram/day and digoxin (Lanoxin) 500 microgram/day were compared in cross-over studies on healthy volunteers and on patients with uncontrolled atrial fibrillation. Serum glycoside concentrations were measured by radioimmunoassay and ventricular rates by ECG. The two regimens appeared to be therapeutically equivalent. 2 The mean serum glycoside concentration in the steady state and the rate at which this state was attained were similar with both drug regimens in the healthy volunteer group. The between-subject variation in serum glycoside concentration was not significantly less during medigoxin administration. 3 The renal clearance of serum glycoside was much lower during medigoxin administration both in healthy volunteers and in patients. This was not due to a difference in serum protein binding. The relatively small dosage requirement for medigoxin was attributed partly to a lower clearance rate and partly to more nearly complete absorption. 4 During the first 2 weeks of the patient study there was a substantial rise in mean serum glycoside concentration and a corresponding fall in ventricular rate. This was attributed to more consistent self-administration of digoxin. The subsequent change to medigoxin had no further effect on mean glycoside concentration, ventricular rate or frequency of ventricular ectopic beats. 5. An attempt to compare the onset of the ventricular rate response to a single oral dose of medigoxin with that to digoxin gave inconclusive results.

Topics: Adult; Analysis of Variance; Atrial Fibrillation; Digoxin; Female; Humans; Male; Medigoxin; Metabolic Clearance Rate

We reported a 79 year old man with preoperative bradycardia due to relative overdose of digitalis prior to undergoing subtotal gastrectomy. The patient had received metildigoxin 0.2 mg.day-1 for atrial fibrillation preoperatively and severe bradycardia of 35-41 bpm was found on the preoperative ECG examination. Serum digoxin level was detected to be 1.91 ng.ml-1 on the day before surgery. We thought this serum level must be toxic for him, even though it was within normal limits for the majority. As we thought that his bradycardia had been caused by relative overdose of digitalis, he was withheld to receive metildigoxin on the day before surgery and thereafter. Heart rate on arrival at the operating theater was around 40-45 bpm, and therefore the patient was placed on a temporary pacemaker catheter before the anesthetic induction to prevent aggravating bradycardia during anesthesia and surgery. Heart rate during procedure was 50-70 bpm and hemodynamics was stable. Intravenous digoxin was restarted on the 2nd postoperative day because of decrease in serum digoxin level to 0.84 ng.ml-1 and it was converted to metildigoxin 0.1 mg.day-1 when he was permitted to take pills per os. Our experience demonstrates that perioperative therapeutic drug monitoring is clinically important for anesthesiologists to make proper pharmacological management of surgical patients who have received digitalis.

Topics: Aged; Anesthesia, General; Anti-Arrhythmia Agents; Atrial Fibrillation; Bradycardia; Drug Monitoring; Drug Overdose; Gastrectomy; Hemodynamics; Humans; Intraoperative Complications; Male; Medigoxin; Pacemaker, Artificial; Stomach Neoplasms

The pharmacokinetics of digitalis glycosides were studied using routine therapeutic drug monitoring data to evaluate the role of patient characteristics for estimating metildigoxin dosing regimens. The 232 serum glycoside concentration data at steady-state after repetitive oral administration in 144 hospitalized patients was analyzed using NONMEM, a computer program designed for population pharmacokinetic analysis that allows pooling of data. Pharmacokinetic analysis of digitalis glycosides was described using a simple steady-state pharmacokinetic model. The effect of a variety of developmental and demographic factors on glycoside clearance was investigated. NONMEM estimates indicated that this digitalis glycoside clearance was influenced by the demographic variables of age, total body weight, serum creatinine, gender, daily dose and the coadministration of spironolactone. An elderly patient was expected to have a lower rate of clearance than a young patient of equal body weight and serum creatinine. The interindividual variability in glycoside clearance was modelled with proportional error with an estimated coefficient of variation of 19.7% and the residual variability was 21.8% The dosing method based on glycoside clearance value obtained by NONMEM analysis allowed the prediction of the minimum steady-state glycoside concentration as a function of metildigoxin maintenance dose with acceptable error for therapeutic drug monitoring.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Arrhythmia Agents; Atrial Fibrillation; Cardiotonic Agents; Female; Heart Failure; Humans; Male; Medigoxin; Middle Aged

Topics: Adult; Aged; Atrial Fibrillation; Chronic Disease; Circadian Rhythm; Digitoxin; Digoxin; Drug Therapy, Combination; Heart Rate; Humans; Medigoxin; Middle Aged; Pindolol; Propranolol

The case of a 73-year-old woman with a 10 year history of mitral valvulopathy in atrial fibrillation is reported. On two occasions spontaneous recovery of sinus rhythm occurred. The first, lasting about 48 hours, followed acute digitalis poisoning. On the second occasion there was a slight intermittent 1st degree A-V blockage, though no glucoside had been taken for about 5 months.

Topics: Aged; Atrial Fibrillation; Female; Humans; Medigoxin; Mitral Valve Insufficiency; Remission, Spontaneous

Topics: Adult; Atrial Fibrillation; Chronic Disease; Digoxin; Female; Heart Rate; Humans; Male; Medigoxin; Middle Aged; Physical Exertion; Rest