EPIDEMIOLOGY OF DIGOXIN - A STUDY IN 3 BOSTON HOSPITALS

Two thousand and ninety-eight consecutive patients have been studied in context of a comprehensive surveillance program which monitored all the drugs which they received. The results with digoxin given to 441 consecutive patients have been reported. The drug was judged to have been effective in 91.7 per cent and poor in 2.8 per cent of all patients in whom a consistent evaluation was made. Adverse reactions were reported in 18.4 per cent of all patients receiving the drug, and these were confirmed in 82.8 per cent of all cases investigated. The major reaction rate was 3.7 per cent. Increased admission weight (p < 0.05), potassium depletion due to diuretics (p < 0.01), and increased admission BUN levels (p < 0.05) were significantly associated with toxicity attributed to digoxin. Within the dosage ranges employed in this study, adverse reactions were not related to mean daily dosage, age, sex, or race. The same held true for efficacy which in addition was unrelated to weight. No deaths were attributed to digoxin. On scanning all drugs given in association with digoxin, toxicity attributed to the drug was found to be significantly associated with the following: meperidine, morphine, heparin, hydrochlorothiazide (all p < 0.05), furosemide, aminophyllin (all p < 0.01), and prochlorperazine (p < 0.001). The findings with meperidine, morphine, and heparin were unexpected, and for the present, are reported without comment. It is suggested that aminophyllin might have an irritative effect on the myocardium and thus potentiate digoxin toxicity. It is emphasized that associations do not necessarily imply cause and effect relationships and that in the context of the drug surveillance program, they could be due to chance, or to the effects of hidden variables. The interaction between digoxin toxicity and the diuretics, hydrochlorothiazide and furosemide, quantitatively supports current clinical and pharmacological knowledge. Prochlorperazine was found to be associated with toxicity because of its use in the treatment of nausea and vomiting caused by digoxin. Given the methodology employed by the surveillance system, this was logical and expected. © 1969.