Allergic Rhinitis and its Impact on Asthma - ARIA

ALLERGIC RHINITIS AND ITS IMPACT ON ASTHMA GUIDELINES ● 2010 – V. 9/8/2010
237). Five trials were done in a laboratory environment <strong>and</strong> reported only data on sedation (227,
229-231, 234).
Benef<strong>its</strong>
Results of the studies that reported comparative efficacy of new generation versus old generation
oral H1-antihistamines were inconsistent. Two studies reported similar relief in nasal symptoms
(173, 228), two favoured old generation antihistamine (193, 235), <strong>and</strong> four favoured new generation
antihistamine (232, 233, 236, 237), although one used a non-st<strong>and</strong>ard high dose of the new
generation medication (237). These variable results were similar to the results of other studies with
terfenedine <strong>and</strong> astemizole included in the health technology assessment by Long <strong>and</strong> colleagues
(225).
Harms
In a systematic review of sedation <strong>and</strong> performance impairment of diphenhydramine <strong>and</strong> new
generation oral H1-antihistamines (226), diphenhydramine decreased performance scores in
comparison with new generation H1-antihistamines to a small or moderate extent (SMD: 0.31; 95%
CI: 0.17–0.45), but the results of individual studies were inconsistent. Statistically significant
difference was observed for self-reported sedation, attention, <strong>and</strong> memory. A small negative effect
on performance was also observed in studies comparing new generation H1-antihistamines to
placebo (SMD: 0.14; 95% CI: 0.01–0.26), but the result is imprecise <strong>and</strong> includes a negligible
difference close to no effect. Significant difference was observed for self-reported sedation <strong>and</strong>
approached significance for reaction time.
In addition, in the 13 studies in allergic rhinitis that we identified, all but three reported less
sedation with new generation oral H1-antihistamines. The three remaining trials were all done in
children <strong>and</strong> concluded there was no difference between the two kinds of medications (231, 232,
234).
Conclusions <strong>and</strong> research needs
There appears to be a net clinical benefit from using new generation oral H1-antihistamines
compared to older ones. Although their comparative efficacy seems similar, there is likely benefit
from avoiding sedation <strong>and</strong> impaired performance. Because we did not conduct our own systematic
review, we based our judgements about the quality of available evidence on unsystematic
examination of the available evidence.
An updated rigorously performed <strong>and</strong> reported (223, 224) systematic review of all individual new
generation oral H1-antihistamines versus old generation oral H1-antihistamines that provides
information on all outcomes important to patients, including adverse effects, is required for the next
update of the ARIA guidelines.
The ARIA guideline panel strongly supports that new generation oral H1-antihistamines be
available worldwide.
Recommendation
In patients with AR, we recommend new generation over old generation oral H1-antihistamines
(strong recommendation | low quality evidence).
Underlying values <strong>and</strong> preferences: This recommendation places a relatively high value on the
reduction of adverse effects, <strong>and</strong> a relatively low value on an uncertain comparative efficacy of new
versus old generation oral H1-antihistamines.
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