[The use of digoxin in primary care]

A study aimed at a population attended at the Primary Health level was designed, in order to reach a greater understanding of the use of Digoxin by doctors and patients.

A crossover observational study, carried out wholly at the Primary Care level.

205 patients under long-term Digoxin treatment were studied. 94 (46%) were men and 111 (54%) women. The average age (SD) was 67 (13).

The indication was considered adequate in 62.9% of patients. The average dose (AD) of Digoxin was 0.163 mg a day (0.04): the age of the patients is not taken into account on working out the dose of Digoxin. 52 patients (25.4%) recognised they had not properly carried out the prescription. In this group the view that Digoxin was unnecessary was more common (X = 10.63; p = 0.001). The average Digoxinemia (AD) was 0.85 (0.46) ng/ml. 57% of patients had plasmatic levels below a therapeutic level. The variables related to plasmatic level were: daily dosage (r = 0.4, p = 0.001); age (r = 0.2, p = 0.001; plasmatic creatinine (r = 0.3, p = 0.001); clearing of creatinine (r = -0.4, p = 0.001) and compliance (t = 2.42, p = 0.01). The same independent variables were identified as significant in the multivariant analysis. The week-end break from dosage supposed a fall in the plasmatic levels of 67.7%.

In spite of being a widely-used drug, the dosage of Digoxin is not adequately worked out and compliance is a long way from the optimum. Digoxinemia correlates to the dosage, renal function and compliance with the prescription.