Adaptive and bayesian control of digoxin in geriatric patients

The study was carried out in a total of 22 patients classified in two groups: Group "A" (n = 12) was constituted by geriatric patients with cardiac failure diagnostic and with digoxin treatment previously to start our study. Group "B" (n = 10) was also constituted by geriatric patients, but with arteriosclerosis diagnostic and without prior digoxin treatment. Doses of 0.25 mg of digoxin was administered by oral route in a multiple dosage regimen with dosification at times of 0, 24, 48, 72 and 96 h. Samples of blood were obtained at 0, 0.5, 1.75, 7, 24, 49.75, 72 and 168 h after the first administration. The classics one and two-open kinetic model were considered. The elimination constant (Ke) was estimated in function of creatinine clearance (Clcr) according to the following expression: Ke = Kslope * Clcr. The mean value of kinetic parameters established were: For one-compartment kinetic model: Ka = 15.2 and 15.7 h-1, Vd = 5.4 and 4.5 l/Kg and Kslope 0.0006 and 0.0001 min/ml * h for groups "A" and "B", respectively. For two-compartment kinetic model: Ka = 11.5 and 3.6 h-1, K12 = 0.7 and 0.8 h-1, k21 = 0.2 and 0.2 h-1, Vc = 2.7 and 1.9 l/Kg and Kslope 0.0002 and 0.0002 min/ml * h for groups "A" and "B", respectively.