Final answer:
Diphenhydramine, known as Benadryl, falls under the class of H1-antihistamines which are used for treating allergy symptoms. These drugs are suitable for short-term use and may not treat chronic allergy-related conditions without a doctor's supervision.
Step-by-step explanation:
Diphenhydramine, also known by the brand name Benadryl, is classified as an H1-antihistamine. These are drugs that are commonly used to treat symptoms of allergies, such as hay fever, and other allergic conditions. They are effective in relieving nasal congestion, sneezing, and hives that can be caused by various allergens like pollen, dust mites, or pet dander. While they are generally well-tolerated and can be purchased without a prescription, antihistamines tend to be for short-term use. People with chronic allergies might require medical consultation as long-term use of antihistamines does not address more serious underlying health issues such as asthma, sinusitis, or respiratory infections.