Clinical question
Do oral antihistamines (AHs) improve symptoms in adults with allergic rhinosinusitis?
Bottom line
Oral AHs reduce rhinosinusitis symptoms by 10% to 30% versus placebo over 2 to 12 weeks. Individual AHs appear to have comparable efficacy. More patients attain moderate improvement or better with intranasal corticosteroids (ICs) (about 80%) versus AHs (about 60%). There appear to be no meaningful differences between AHs and leukotriene receptor antagonists or when adding AHs to IC use.
Evidence
Results were statistically significant unless noted.
Antihistamines versus placebo over 2 to 12 weeks:
- Systematic review (7 RCTs, 1218 patients)1 found that for patient-rated nasal obstruction scores (scale 0 to 3), baseline=1.65; placebo improved symptoms 16% and AHs 48%.
- Systematic review (5 RCTs, 3329 patients)2 of bilastine (newer AH) found total symptom score effect size=0.28, similar to improving symptoms 10% to 16% over placebo.3
Antihistamines versus other AHs:
Antihistamines versus other agents:
- Two systematic reviews (5 to 16 RCTs, 990 to 2267 patients) compared ICs with AHs over 2 to 8 weeks.5,6 Total nasal symptom scores improved more with ICs (51% vs 31%). Proportion attaining moderate control or better7 was higher with intranasal steroids (78%) versus AHs (58%); number needed to treat=5.
- Systematic review (13 RCTs, 5066 patients)8 of AHs plus ICs versus ICs alone over 2 to 6 weeks found antihistamines did not add clinically meaningful benefit.
- Two systematic reviews (9 to 14 mixed-design studies, 4458 to 5781 patients) of AHs versus leukotriene receptor antagonist over 1 to 12 weeks found no clinically meaningful differences.9,10
Context
Adverse event data are reported infrequently and difficult to interpret.11 Some AHs may have less of a sedative effect: eg, bilastine (3%) versus cetirizine (7%).2
Estimated cost for 30-day supply: cetirizine 10 mg, desloratadine 5 mg, or fexofenadine 120 mg, $25; bilastine 20 mg, $45; mometasone 50 μg or beclomethasone 50 μg, $25; fluticasone 50 μg, $40.12
Implementation
Antihistamines have comparable efficacy, so choice should be based on cost and adverse event profile. Patients presenting in primary care typically have moderate to severe rhinosinusitis symptoms and more patients are likely to benefit from nasal steroids versus AHs.13 Improvement with nasal steroids may take several days and full effect can take up to 2 weeks.13
Notes
Tools for Practice articles in CFP are adapted from peer-reviewed articles at http://www.toolsforpractice.ca and summarize practice-changing medical evidence for primary care. Coordinated by Dr G. Michael Allan and Dr Adrienne J. Lindblad, articles are developed by the Patients, Experience, Evidence, Research (PEER) team and supported by the College of Family Physicians of Canada and its Alberta, Ontario, and Saskatchewan Chapters. Feedback is welcome at toolsforpractice{at}cfpc.ca.
Footnotes
Competing interests
None declared
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La traduction en français de cet article se trouve à https://www.cfp.ca dans la table des matières du numéro de septembre 2022 à la page e268.
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