The potential negative impact of antibiotic pack on antibiotic stewardship in primary care in Switzerland: a modelling study.

In Switzerland, oral antibiotics are dispensed in packs rather than by exact pill-count. We investigated whether available packs support compliance with recommended primary care treatment regimens for common infections in children and adults.Hospital-based guidelines for oral community -based treatment of acute otitis media, sinusitis, tonsillopharyngitis, community-acquired pneumonia and afebrile urinary tract infection were identified in 2017 in an iterative process by contacting hospital pharmacists and infectious diseases specialists. Furthermore, newly available national guidelines published in 2019 were reviewed. Available pack sizes for recommended solid, dispersible and liquid antibiotic formulations were retrieved from the Swiss pharmaceutical register and compared with recommended regimens to determine optimal (no leftovers) and adequate (optimal +/- one dose) matches.A large variety of recommended regimens were identified. For adults, optimal and adequate packs were available for 25/70 (36%) and 8/70 (11%) regimens, respectively. Pack-regimen matching was better for WHO Watch (optimal: 15/24, 63%) than Access antibiotics (optimal: 7/39, 18%). For the four paediatric weight-examples and 42 regimens involving child-appropriate formulations, optimal and adequate packs were available for only 14/168 (8%) and 27/168 (16%), respectively. Matching was better for older children with higher body and for longer treatment courses > 7 days.Fixed antibiotic packs often do not match recommended treatment regimens, especially for children, potentially resulting in longer than necessary treatments and leftover doses in the community. As part of national stewardship, a move to an exact pill-count system, including for child-appropriate solid formulations, should be considered.