"Drugs often have several names. When a drug is first discovered, it is given a chemical name" that describes its molecular composition and what it does, according to Merck Medical in the "Home Health Handbook."
Antihistamines are known by several over-the-counter and prescription names, but they are classified by what they do, which is reduce or eliminate histamine in the body and relieve allergy symptoms.
Brompheniramine
The National Institutes of Health lists brompheniramine as an antihistamine used to relieve watery eyes, itching, and runny nose caused by allergies. Brompheniramine blocks histamine to reduce allergy symptoms.
Drugs.com says brompheniramine has sedative effects and should not be used by children, as it has been noted as fatal in some cases.
Brompheniramine is sold under the brand Dimetapp.
Diphenhydramine
The antihistamine diphenhydramine is used in products from Benadryl and Tylenol for its sedative and allergy symptom relief. Diphenhydramine use for allergies helps to relieve runny nose, sneezing and itchy eyes.
Diphenhydramine's sedative properties can cause drowniness and should be used only by adults.
Doxylamine
Doxylamine is used mainly in night-time allergy remedies to aid with sleep. Doxylamine combined with other ingredients alleviates symptoms like itchy eyes and sneezing. With its sedative properties, brands such as Nyquil use it in its night-time relief formulas. Doxylamine reduces histamine and allows ease with breathing through the night.
