First-Generation H1-Antihistamine Prescribing in Hospitalized Patients A Quality Improvement Measure

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Sarah Lohrenz
Kavya Yatham
Sandy Kassir
Andrea Fong


First-generation H1-antihistamines, adverse effects


First-generation H1-antihistamines are commonly utilized in hospital, however, these agents are associated with a number of undesirable adverse effects such as central nervous system (CNS) depression, cardiotoxicity and death in overdose.
We performed a retrospective analysis of all first-generation antihistamine prescriptions at the Regina General Hospital over the past year from January 1, 2019 – January 1, 2020. A total of 6,972 prescriptions were written during the study period, 6,692 (96%) of which were for first-generation antihistamines. The largest number of prescriptions for first generation antihistamines was in surgery, followed by internal medicine, and obstetrics and gynecology.
Physicians, pharmacists, and nurses in these areas may benefit from education around the potential for serious harm of first-generation antihistamines and the availability of safer alternatives. Additionally, limiting access to first-generation antihistamines in hospital would encourage safer prescribing habits and familiarity with second-generation agents.

Les antihistaminiques H1 de première génération sont couramment utilisés en milieu hospitalier. Toutefois, ces agents sont associés à un certain nombre d’effets indésirables comme la dépression du système nerveux central (SNC), la cardiotoxicité et le décès causé par une surdose.
Nous avons effectué une analyse rétrospective de toutes les ordonnances d’antihistaminiques de première génération délivrées à l’hôpital régional de Régina au cours d’une année, soit du 1er  janvier  2019 au 1er  janvier 2020. Au total, 6972 ordonnances ont été rédigées au cours de la période à l’étude, dont 6692 (96 %) pour des antihistaminiques de première génération. Le plus grand nombre d’ordonnances d’antihistaminiques de première génération ont été rédigées en chirurgie, suivie de la médecine interne et de l’obstétrique et de la gynécologie.
Les médecins, les pharmaciens et les infirmières de ces secteurs pourraient tirer profit d’une formation sur le potentiel de dangerosité des antihistaminiques de première génération et sur l’existence de solutions de rechange plus sûres. En outre, le fait de limiter l’accès aux antihistaminiques de première génération en milieu hospitalier favoriserait des habitudes d’ordonnance plus sûres et la familiarisation avec les agents de deuxième génération.

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