A survey on diarrhea and convenience of intake associated with a single-dose extended release formulation of azithromycin

The development of a single-dose extended release formulation of azithromycin (AZ-SR) improves the adherence. However, gastrointestinal side effects such as diarrhea are frequent adverse drug reactions. The aim of the present study was to investigate the incidence of patient-reported in a diarrhea and the convenience of intake of AZ-SR in an Asian population. To assess the incidence of diarrhea and convenience of intake, patient-reported in a questionnaire about the incidence, onset, duration and severity of diarrhea, shape of stool, and patients' impression on taste. The drug was prepared and used in common with the hospital pharmacy and the community pharmacy. AZ-SR was prescribed in 96 outpatients, among whom 81 patients received the medicine and the questionnaire at the hospital pharmacy or one of five neighboring community pharmacies. The recovery of the questionnaire was 40.7%. Diarrhea occurred in 18 of 33 patients (54.5%), which was more frequent than in earlier reports, although the symptom was mild (grade 1–2) and occurred in most cases within 2 days. Approximately one third of patients reported inconvenience in taking the formulation in respect of the ease (36.4%), amount (42.4%), and unpleasant bitter taste (36.4%). We report here the importance of collaboration between hospital pharmacists and community pharmacists in providing accurate drug information, including the incidence of diarrhea, to patients receiving AZ-SR.