Does the frequency of daily dosage influence compliance with digoxin therapy?

Abstract

1 The influence of daily dosage frequency on drug compliance has been studied in 80 outpatients for whom maintenance digoxin 0.25 mg daily had been prescribed. 2 Each patient took one tablet (0.25 mg) daily, two tablets (0.125 mg) daily and four tablets (0.0625 mg) daily in randomised order for 2 month periods. 3 Compliance was assessed by tablet counting and by serial measurement of the plasma digoxin concentration.4 Of the 67 patients (100%) who could have completed the study, 19 (28.4%) were withdrawn for a variety of reasons; in the majority these were consistent with gross non-compliance. 5 The remaining 48 patients (71.6%) took significantly more tablets when prescribed once daily (98.5 + 1.0% of the total) or twice daily (96.4 + 1.6%) than when given four times daily (92.2 + 1.9%). However, there were no significant differences between the plasms digoxin levels obtained at the three dosage frequencies. 6 We conclude that the small improvement in compliance with once or twice daily dosage was clinically unimportant. Dosage frequency did not appear to have a major influence on the grossly non-compliant patients.

Patient compliance with oral theophylline therapy.

“…In view of this, it is perhaps surprising to find such a large number of patients who were grossly non-compliant, that is who had discontinued their treatment or took it only occasionally (19 patients or 30.2%). However, in a previous study of the influence of daily dose frequency on compliance with digoxin treatment, we also found that about 30% of patients were grossly unreliable, making measurements of the effects of different tablet numbers in them impossible (Taggart et al, 1981). One might have expected that a symptomatic illness such as obstructive airways disease would encourage compliance, but so many patients were receiving theophylline in amounts which produced plasma levels below 10 jig/ml or even below 5 ug/ml that it seems unlikely that failure to take the drug would result in symptomatic deterioration.…”

Compliance with drug therapy.

“…for such studies and accurate methods are needed. However, he also stressed that clinically important endpoints should be used, citing a study by Taggart et al (1981) which concluded that compliance with digoxin prescribed as a four times a day regimen was worse than with a once daily or twice daily regimen, but that the slightly lower digoxin levels on the four times a day regimen were unlikely to be of clinical importance.…”

Drug Use in the Elderly: Issues of Noncompliance

“…Dosage frequently does not appear to have a major influence on the grossly noncompliant patient. 15 Other Considerations of Risk DISEASES The provider may want to factor the patient's diseased state into the process of establishing whether a patient is at risk of noncompliance. There are, of course, many disease states that pose a special risk to the elderly patient; several are mentioned here.…”