digoxin and Postgastrectomy-Syndromes

In 47 patients with disorders of the gastrointestinal tract, the bioavailability of digoxin tablets was assessed by measuring the area under the serum concentration-time curve (AUC) after the oral administration of single 0.5 mg doses. In 13 or 14 patients who had undergone a previous ileal resection, in 10 of 10 patients with sprue and in 14 of 14 patients with a variety of disorders of the gastrointestinal tract, digoxin absorption was normal despite marked steatorrhea in many. A patient with extensive jejunal and ileal resection, and inflammation of the remaining small bowel,was the sole exception. Impaired digoxin bioavailability was found in five of nine patients who had undergone jejunoileal bypass procedures (bypass patients. A strong correlation was noted between the length of jejunum remaining in continuity and the AUC (r = 0.86, p less than 0.01). Two of three bypass patients also showed decreased absorption of more rapidly dissolving tablets or an elixir. Digoxin bioavailability correlated significantly with and 2 hour serum xylose levels but not with urinary xylose excretion, fecal fat or the Schilling test result. The findings are consistent with the role of the upper small bowel as the predominant site of digoxin absorption as well as the reserve function of the ileum in the event of jejunal dysfunction or bypass.

Topics: Adult; Aged; Biological Availability; Celiac Disease; Digoxin; Female; Gastrointestinal Diseases; Humans; Ileum; Intestinal Absorption; Jejunum; Male; Middle Aged; Postgastrectomy Syndromes; Xylose

Biological availability of digoxin tablets was measured during maintenance therapy in ten hospitalized patients who had had a Billroth II gastric resection at least two years previously. Twelve patients on digoxin maintenance for heart failure but without gastro-intestinal disease served as controls. The mean value of daily digoxin urinary excretion over ten days in the resection group was 38.09 +/- 0.70% of the administered dose. The serum-digitalis level 12 and 24 hours after the last dose of glycoside (0.5 mg) was 1.30 +/- 0.04 ng/ml and did not significantly differ from that of the control group, nor did digoxin elimination in urine and the digoxin/creatinin excretion ratio. It is concluded that two-third gastric resection with exclusion of antigrade duodenal passage does not influence biological availability of digoxin given in tablets.

Topics: Adult; Aged; Biological Availability; Creatinine; Digoxin; Female; Gastrectomy; Humans; Long-Term Care; Male; Middle Aged; Postgastrectomy Syndromes