ABSTRACT
BACKGROUND: Oral nitrates, beta-blockers, and calcium channel blockers are used to treat stable angina pectoris (SAP). The 2 therapeutic subtypes of oral nitrates are mononitrates and dinitrates, with no evidence that 1 subtype is more efficacious than the other. Although practice guidelines in Great Britain and Israel recommend dinitrates as the first-line drug for SAP, in practice, many physicians in those 2 countries prescribe mononitrates. OBJECTIVE: The aim of this study was to identify factors that influence specialist physicians (family practitioners, internists, and cardiologists) in Israel when prescribing nitrates for the prevention of SAP symptoms. METHODS: A group of specialists was given a self-administered questionnaire regarding their treatment of choice for a patient with SAP described in a hypothetical case vignette. End points for prescribing preferences were evidence-based information, cost, and the influence of pharmaceutical company representatives. RESULTS: One hundred ten specialists were given the questionnaire. Eighty-nine specialists (45 men, 44 women; mean age, 50.4 years; range, 34-67 years; response rate, 80.9%) completed it (39 family practitioners, 29 internists, and 21 cardiologists). Seventy-eight respondents (87.6%) chose to prescribe nitrates for the case vignette, and among those, 54 (69.2%) chose mononitrates and 24 (30.8%) chose dinitrates (P = 0.034). The choice of mononitrates over dinitrates was mainly affected by habit (25/54 [46.3%]) and the belief that mononitrates are more effective, safer, and/or less expensive than dinitrates (21/54 [38.9%]). Drug costs for the patient significantly influenced more family practitioners than hospital specialists (P<0.05). CONCLUSIONS: In contrast to guideline recommendations, the paradigm of SAP treatment with nitrates in this study was characterized by significantly more prescriptions for mononitrates than dinitrates. This situation contributes to the erosion of the scarce resources of the health care system in Israel. Further efforts are needed to increase physicians' awareness of quality, cost, and choices when prescribing drugs.
ABSTRACT
BACKGROUND: Because of its narrow therapeutic index, therapeutic monitoring of digoxin is important in the management of infants and children receiving the drug for cardiac failure or arrhythmias, or following accidental ingestion. Whether saliva can replace plasma in the therapeutic monitoring of digoxin therapy in children is unclear. OBJECTIVE: This study assessed the value of determining saliva digoxin concentration in infants, children, and adolescents. METHODS: Infants, children, and adolescents receiving digoxin for various indications, whose digoxin dosage had remained unchanged for ≥10 days, and whose compliance was good according to the parents were enrolled. Digoxin concentration was measured in paired specimens of citric acid-stimulated mixed saliva and plasma obtained simultaneously. RESULTS: Eighteen children (10 boys, 8 girls; mean [SD] age, 42.3 [53.1] months [range, 2 months-14 years]) were included in the study. Digoxin therapy was administered for cardiac failure due to dilated cardiomyopathy in 9 patients (50.0%), ventricular septal defect in 4 (22.2%), supraventricular tachycardia in 3 (16.7%), and after cardiac surgery in 2 (11.1%). Digoxin concentration in the 20 paired specimens obtained varied from 0.0 to 0.92 ng/mL (mean [SD], 0.25 [0.26] ng/mL) in saliva and from 0.27 to 1.54 ng/mL (mean [SD], 0.77 [0.40] ng/mL) in plasma. The mean plasma/saliva digoxin concentration ratio was 2.8. CONCLUSIONS: This study of infants, children, and adolescents receiving digoxin for a variety of indications and whose dose was unchanged for ≥10 days showed that marked individual variability in the saliva/plasma concentration ratio precludes the use of saliva in predicting the plasma digoxin concentration. The value of saliva digoxin (as opposed to plasma digoxin) measurements in the assessment of the cardiac effects of the drug in children remains to be determined.
