Diuretic Drug Utilization Study

Abstract

Objective: To evaluate the present use of diuretics in our institution, and determine the appropriateness of that use and the incidence of adverse reactions and interactions. Design: This retrospective study describes the indications for use of an identified drug or combination of drugs. By the time the data were collected, some patients had been discharged or had died. Setting: The study was carried out in a referral center, the University Hospital “Virgen Macarena,” Seville, Spain. Patients: All patients receiving diuretic therapy. Those undergoing hemodialysis or receiving home care were excluded from the study. Intervention: A therapeutic audit was performed using specific standards of reference. Two models were used — one for each of the most frequent indications, ascites and congestive heart failure (CHF). Main Outcome Measures: A structured protocol gathered data on (1) demographic characteristics, (2) causes of admission and pathologic antecedents, (3) diuretic treatment, (4) basic controls (24-h diuresis and daily basal weight), (5) clinical evolution, and (6) concurrent complementary studies. The protocol included a checklist of the most frequent adverse drug reactions and interactions whose degree of causality was determined by applying the modified algorithm of Karch-Lasagna, used in the World Health Organization voluntary reporting system of adverse drug reactions. Results: One hundred twenty-six patients (16% of total admissions) received diuretic therapy. Of these, 71% were analyzed; information in the medical records was incomplete for the rest (29%). Fifty-one percent of the patients were more than 60 years old. The most frequent admission diagnoses were cardiovascular (51.5%), followed by digestive (16.7%) diseases. A total of 134 cardiac symptoms was seen in 50 patients. The most notable were acute pulmonary edema (26%), ischemic cardiopathy (12%), and cardiogenic shock (8%). Most patients receiving diuretic therapy (47.3%) were admitted to the internal medicine service. The most-prescribed diuretic was furosemide (59%), followed by spironolactone (27%). The combined use of furosemide and spironolactone occurred in all but 1 of the patients with hepatic ascites (92%), whereas in those with CHF the figure for the combined use of furosemide and spironolactone fell to 38% (p = 0.001). In 63% of the patients with ascites, the spironolactone dosage was changed in the first 48 hours of treatment. There was a high percentage of deaths (21%) in the study patients. Conclusions: Therapeutic strategy often does not follow the guidelines laid down in the standards of reference on diuretic use in serious CHF and/or ascites in this institution.