According to the Edmonton Sun, a pilot "was killed in a helicopter crash near Wabasca while fighting a forest fire. He crashed his helicopter into the woods while loading a massive water bucket in a nearby lake.
The pilot was suffering from allergies and had taken the antihistamine Reactine, which can lead to drowsiness and is not recommended for use while operating machinery. He had taken a quantity of allergy medication that could have affected his ability to stay alert."
Reactine (cetirizine) is marketed in the U.S. as Zyrtec. Formerly prescription-only, it is now available over the counter.
Second generation antihistamines have greater H1-receptor specificity than first generation. Cetirizine, loratadine, and desloratadine have dose-related sedation which is not detectable in the FDA approved doses. Fexofenadine has no greater sedative effect than placebo in every dose studied.
Free of sedation at any dose
It is probably safer to use fexofenadine (Allegra) in pilots and operators of vehicles and heavy machinery rather than the other second generation antihistamines currently available on the market.
Training an issue in chopper crash. Edmonton Sun.
Cetirizine, from Wikipedia, the free encyclopedia.
Allergic Rhinitis. Allergy Cases.
Image source: Wikipedia, GNU Free Documentation License.
The Best Antihistamines for Sneezing and Nasal Congestion. Paul Enright, MD, 04/2008.
Patient response to different antihistamines will vary http://goo.gl/Q2PiV