Do antihistamines help with cold symptoms?”
Antihistamines basically work by counteracting histamine, which is a substance that our body overproduces in response to an allergy. A cold is caused by an infection by a virus, not by allergens, so an antihistamine wouldn’t have any or much effect. Now, many people mistake an allergy response for a cold, because they have many of the same symptoms, like sneezing and stuffy nose. However, they probably get their “cold” at the same time each year (if environmental allergy) or after each exposure to the offending allergen (“Wow, everytime I go visit Aunt Marge and her 10 cats, I always catch a cold.”), while a true cold caused by a virus would be more random and/or after exposure to known sick people. Such people would see their symptoms helped by an antihistamine. Also, many antihistamines sold over-the-counter are not pure antihistamine, but rather combined with a decongestant. (Ex. Claritin vs. Claritin-D.) A decongestant helps people who have a true cold by loosening mucus in stuffy
These help stabilize mast cells that release the cold symptoms in the presence of an allergen. If there is no allergen, and you have cold symptoms – you have a cold from a virus and this will help in no way. If you have other symptoms of a cold, like a fever, cough, etc. then pass on the antihistamines.
But for many people, antihistamines may help relieve sneezing and runny nose from a cold. When your nose and sinuses are affected by a cold virus, special cells in your nose and sinuses release a chemical called histamine. Histamine causes the tissues in your nose to itch and swell and to alter the mucus it secretes so that the mucus becomes clear and runny. Antihistamine cold medicines block histamine from interacting with the nasal tissues, preventing sneezing and runny nose. Only the older antihistamines, such as brompheniramine and chlorpheniramine, are effective at relieving cold symptoms. Their main side effect is drowsiness, which makes them difficult for some people to take during the day. That’s why antihistamines are often included in nighttime cold medicines. Newer antihistamines like Allergra and Claritin have not been shown to work against cold symptoms.
