Seasonal and daylight saving time–related variation in hydroxyzine prescribing: Evidence of circadian and environmental modulation in primary care

Hydroxyzine is commonly used off-label as a hypnotic medication because of its sedative properties. The available data on hydroxyzine use in primary healthcare are limited, and the impact of seasonal factors on its prescribing has not been investigated. This study examined whether environmental photoperiod and circadian misalignment related to daylight saving time (DST) transitions modulate hydroxyzine prescribing patterns in primary care. A retrospective analysis was conducted, covering 13 625 medical consultations provided to adult patients (≥18 y of age) at a primary healthcare centre in Olsztyn, Poland, between 2012 and 2024. Prescriptions for medications containing hydroxyzine were identified using the ATC classification (N05BB) and analysed by season, sex, and periods before and after the spring and autumn DST transitions. After adjustment for the number of patients registered at the centre, women were prescribed hydroxyzine 2.76 times more often than men. A significant seasonal prescribing pattern was observed. In both women and men, the average daily number of prescriptions was highest in winter and lowest in summer. The relative winter - summer increase was 11.4% in women and 37.5% in men. DST transitions were not associated with any measurable change in hydroxyzine prescribing. Hydroxyzine prescribing in primary healthcare showed a clear seasonal pattern and marked sex-related differences. These findings may suggest frequent use of hydroxyzine for sedative, anxiolytic, or sleep-promoting purposes, whereas DST transitions did not appear to affect prescribing patterns.