re antihistamine for sleep aid in article apr ux cts eiu edu cfaks ux cts eiu edu alice sanders writes but after you have taken antihistamines for a few nights doesn t it start to have a paradoxical effect i used to take one every night for allergies and couldn t figure out why i developed bad insomnia insomnia is a known but relatively infrequent side effect of diphenhydramine for most people this does not occur on the other hand most people can build up a tolerance to an antihistamine with extended use allergy sufferers are often switched from one antihistamine to another to avoid this steven litvintchouk mitre corporation burlington road bedford ma fone arpa sdl mitre org uucp linus sdl
