Pharmacokinetic monitoring of chronic treatment with digoxin from Primary Health Care.

Introduction: The serum digoxin concentration (SDC) should be between 0.8 and 2 ng/ml. The objective is to assess the pharmacokinetic monitoring of SDC performed from primary healthcare (PH) in patients with chronic treatment.

Methods: Cross-sectional retrospective study of patients with chronic treatment with digoxin belonging to the department of a General University Hospital.Data were analized: age, sex, diagnosis, number of serum digoxin concentration determinations, date and origin of the request for monitoring, analytical result and pharmacokinetic assessment are collected.

Results: 624 patients are undergoing chronic treatment with digoxin, 68% women, mean age 78.4 (39-98) years. 308 (49.4%) patients haven't analytical determination of SDC (Group 1), 183 (29.3%) patients have a SDC occasionally performed with a request from specialist care (Group 2) and 133 (21,3%) patients have CSD performed with a request from primary healthcare doctors, with an average of 2.42 monitoring per patient and year (Group 3). These are those patients who have pharmacokinetic monitoring of chronic treatment with digoxin. Of the group 2.25 (13.6%) patientes were hospital admission from emergency department for presenting digitalis intoxication with CSD>2 ng/ml, and 39 (21.3%) patients for low dosing with CSD<0.5 ng/ml. Group 3.4 (3%) patients presented digitalis intoxication and 5 (3.8%) for insufficient dosing.

Conclusions: A small proportion of patients undergoing chronic treatment with digoxin are under pharmacokinetic monitoring and a reduction in complications derived from inappropriate CSD compared to those not under pharmacokinetic follow-up is observed.