Objective: To assess drug-compliance observed among patients with suspected streptococcal pharyngitis treated with twice-daily antibiotic regimens (b.i.d.) and others with thrice-daily regimens (t.i.d.).
Methods: A prospective study in the primary care setting was designed in which patients with pharyngitis and three or more Centor criteria, non-allergic to beta-lactam agents, treated with several b.i.d and t.i.d antibiotic regimens based on doctor's choice, were recruited. Patient compliance was assessed with electronic monitoring.
Results: A total of 113 patients were enrolled (64 in the t.i.d. group and 49 in the b.i.d. group). Mean openings ranged from 70.3 to 83.3% of the total amount of pills. All the parameters analysed indicated significantly worse compliance with the t.i.d. regimens. Eleven patients allocated to the t.i.d. group took at least 80% of the pills (17.2%), this being significantly lower than those who received b.i.d. antibiotics (59.2%; p < 0.001). The percentage of patients who opened the Medication Event Monitoring System (MEMS) container the satisfactory number of times a day was systematically lower among t.i.d. regimens, this being statistically significant from day three (p < 0.05). Patients assigned to t.i.d. regimens more frequently forgot the afternoon dose.
Conclusion: Compliance rate was very low, mainly when patients are given t.i.d antibiotic regimens. This may lead to storage of antibiotics and subsequent self-medication. New strategies addressed to improve drug-compliance with antibiotics among outpatients are therefore necessary.