It is extremely dangerous to administer human medications to pets without explicit instructions from a veterinarian. Chloritrimiton is a human antihistamine, and it can be toxic to dogs.
If you suspect your dog has ingested Chloritrimiton or any other medication, contact your veterinarian or the ASPCA Animal Poison Control Center immediately.
The ASPCA Animal Poison Control Center can be reached at (888) 426-4435.