IMPACT OF DOSAGE FREQUENCY ON PATIENT COMPLIANCE

OBJECTIVE - To evaluate the impact of dosage frequency on the complian ce of patients who receive their medicines from community pharmacies. RESEARCH DESIGN AND METHODS - Each month, patients received a supply o f their medication in a Medication Event Monitoring Systems container, which registered each opening of the package. Ar the end of the study the patients received a short questionnaire. The subjects were 91 dia betic patients using oral antidiabetic agents. Patients taking insulin and those who were unable to collect their medicines from the pharmac y were excluded from the study. Compliance was defined as the percenta ge of doses taken during the observation period. Another parameter use d was compliance with the prescribed regimen, defined as the percentag e of days in which the number of tablets were taken as prescribed. As a last parameter. compliance with the prescribed dose intervals was us ed. RESULTS - Compliance is influenced by the frequency of doses. The compliance for this group of patients is 74.8%, with an average of 79% in the case of a dose once daily and 38% in the case of a dose three times daily The predominant type of noncompliance in all groups was do se omissions. However, more than one-third of the patients used more d oses than prescribed. Overconsumption is a frequently made mistake by patients on a one-dose daily schedule. CONCLUSIONS - The reduction of dose frequency may decrease total noncompliance, but at the same time, it increases the risk of overconsumption. Reducing the frequency does not automatically result in a better therapeutic schedule. The choice of once or twice daily should depend on the therapeutic range of the drug.