How patients use repeat antibiotic prescriptions: the impact of dosing directions

Background: Repeat prescribing of antibiotics is widespread in Australia. This may be associated with risks to individual patientsand contribute to inappropriate antibiotic use.Aim: To characterise the time intervals between dispensing of initial and repeat antibiotic prescriptions, and identify any associationsbetween these intervals and information on treatment duration included in dosing directions.Method: A retrospective study of de-identified antibiotic repeat dispensing records from 186 Australian pharmacies.Results: A total of 12 516 repeat dispensings for amoxicillin/amoxycillin (5198, 41.5%) and cefalexin/cephalexin (7318, 58.5%) wereanalysed. Of these, 50.7% (6340) and 78.8% (9863) were collected within 2 and 30 days of the date on which the original supplyshould have been completed, respectively. The remainder were dispensed throughout the following 11 months. Compared to prescriptionswith no reference to duration or a generic statement regarding course completion, specifying a course length exceedingthat provided by the initial pack was associated with a significantly shorter interval between the dispensing of original and repeatprescriptions.Conclusion: Around half of all supplied repeats appear to be used to extend initial courses, while around 1 in 5 repeat dispensingsoccur at least 1 month after the initial prescription, suggesting that they may be used to treat separate episodes of infection. Theinclusion of specific information regarding treatment durations on prescriptions and in dispensing directions appears to influencepatient behaviour. While addressing the whole practice of issuing antibiotic repeats remains desirable, these findings may be relevantfor prescribers and pharmacists, and help efforts to extend antimicrobial stewardship principles to the community