The Review Course in Family Medicine
Update on Antihistamines - When should they never be prescribed?
Antihistamines should only be used to treat allergic rhinitis, urticaria, and conjunctivitis.
Do NOT use for asthma, eczema, cough, or insomnia management.
Be mindful of the side-effect profile associated with first-generation antihistamines, including the anticholinergic and anti-alpha-adrenergic properties which can result in prolonged QT and death.
DO NOT use in elderly populations or with alcohol.
Stick to the approved list: Bilastine, Cetirizine, Desloratadine, Fexofenadine, Loratadine and Rupatadine. These newer antihistamines should be selected when available. Their heightened safety profile and increased duration and speed of action make them a much preferable choice.
DO NOT replace epinephrine with antihistamines in the treatment of anaphylaxis.
Antihistamines MAY be used in ADDITION but beware of hypotension.
Do not be afraid to use antihistamines in pregnant or breastfeeding women or children; they have been deemed safe in both these populations.
Inadequate evidence regarding rupatadine and bilastine
How to use antihistamines
CMAJ April 06, 2021 193 (14) E478-E479; DOI: https://doi.org/10.1503/cmaj.201959