Comparison of two nomograms of unfractionated heparin in patients with acute coronary syndrome

Heparin has an unpredictable pharmacokinetics and the responses of individuals may vary distinctly. Therefore, different dosing nomograms have been proposed. The aim of this study was to compare two prevalent nomograms to adjust heparin doses in hospitalized patients with acute coronary syndrome. One hundred and forty patients received heparin infusions based on one of two nomograms. Group 1 received a bolus of 80 U/Kg/h and an initial infusion rate of 17 U/Kg/h. In the second group, a bolus of 60 U/Kg [maximum of 4000 U] and an initial infusion rate of 12 U/Kg/h [maximum of 900 U/h] was given. Activated partial thromboplastin time [aPTT] was measured at the beginning and every 6 h for 48 hours. The rate of heparin was changed according to each nomogram in order to maintain aPTT in the therapeutic level of 46-70 s. The time to pass threshold was on average 7.63 +/- 3.95 h for nomogram 1 and 11.05 +/- 4.41 h for the second nomogram [P<0.001]. At 48 hours, the proportion of patients in the therapeutic range in group 1 was higher [72.86% vs 45.71%]. The time patients stayed at the desired levels was significantly higher in nomogram 1 and they also required fewer heparin rate adjustments [3.41 +/- 1.55 vs 4.53 +/- 1.63]. This study indicated that using nomogram 1 facilitated a more rapid achievement of the therapeutic threshold, higher proportion of patients in the therapeutic range for a longer time, and fewer changes of in the heparin rate

Evaluation of the relationship between steady state serum digoxin concentration and toxicity

This study was conducted to determine the serum digoxin concentration [SDC] at which there is an increase in the signs and symptoms of digoxin toxicity. Demographic characteristics, disease[s], clinical and para-clinical signs and symptoms of 79 patients who were using digoxin for at least one month were recorded. Prolonged PR, bradycardia, shortened QT, PVC [especially with bigeminy], sinus arrest, junctional extrasystole and symptoms like nausea/vomiting, diarrhoea, anorexia, fatigue, headache and visual disturbances were defined as symptoms of toxicity. From 1.2 ng/ml an increase in electrophysiological signs of toxicity was observed and it rose steeply at SDCs above 1.6 ng/ml. No relationship was found between SDC and symptoms of toxicity. Signs of digoxin toxicity appear even at levels below 2.0 ng/ml. Thus, target SDC should not exceed 1.6 ng/ml

Digoxin compliance: a pharmacokinetic quantification

To quantify extent of compliance in patients receiving digoxin by implementing an applied pharmacokinetic approach and to determine the percentage of patients with levels within therapeutic range. One hundred-nineteen patients, whom met the required criteria, were enrolled in this study. Based on their digoxin doses, they were divided into 4 groups. Group A took 1 tablet [0.25 mg] per day, group B received half a tablet [0.125 mg] each day, group C used 6 tablets per week, and group D took 5 tablets per week and two days were off the drug. A pharmacokinetic approach was used to predict the serum digoxin concentrations of patients and the expected levels were compared with the actual concentrations. 52.29% of patients were compliant. There was no significant difference between the compliant and non-compliant groups with regard to gender, age, and number of concurrent medications or duration of digoxin intake. However, with respect to their doses, a significant difference existed between 2 groups [p<0.01]. Patients in group D were more compliant [80.56%]. In addition, their serum digoxin concentrations were relatively more within the therapeutic range [89.66%]. Therefore, patients with the lowest frequency of digoxin intake were more compliant. The results of this study indicate that a considerable number of patients do not take digoxin as directed. Patients with the least frequency of digoxin intake were relatively more compliant