title: Use of a pharmacologic indicator to compare compliance with tablets prescribed to be taken once, twice, or three times daily.
abstract: By use of an interview, return tablet count, and a pharmacologic indicator (low-dose phenobarbital), we compared compliance with tablets prescribed to be taken once, twice, or three times daily. One hundred seventy-nine patients with type II diabetes were randomly allocated to take one 2 mg phenobarbital tablet once, twice, or three times daily for 28 days. Phenobarbital level/dose ratios indicated that compliance was similar with once- and twice-daily regimens, and both were better than thrice-daily dosing. Mean return tablet counts suggested that compliance was best with the once-daily regimen; both twice- and thrice-daily regimens were similarly inferior. This difference between the techniques may be explained by the inadequacies of the residual tablet count, which identified only 13% of cases identified by phenobarbital. We conclude that compliance with the once-daily regimen was best, but that compliance with a twice-daily regimen was very similar, and both were superior to dosing three times a day.
authors.affiliation: Department of Pharmacology, University of Leeds, England.
authors.forename: T
authors.initials: T
authors.lastname: Pullar
authors.forename: A J
authors.initials: AJ
authors.lastname: Birtwell
authors.forename: P G
authors.initials: PG
authors.lastname: Wiles
authors.forename: A
authors.initials: A
authors.lastname: Hay
authors.forename: M P
authors.initials: MP
authors.lastname: Feely
mesh_terms: D004334:Drug Administration Schedule; D006801:Humans; D008722:Methods; D008875:Middle Aged; D010349:Patient Compliance; D010634:Phenobarbital / Q000008:administration & dosage* / Q000097:blood
chemical_list: D010634:Phenobarbital