Final answer:
Antihistamines mitigate allergy symptoms by blocking histamine receptors. H₁-antihistamines and H₂-antihistamines target different receptors to treat symptoms like runny nose or gastric acid issues. Antihistamines are available over-the-counter and in prescription forms.
Step-by-step explanation:
Antihistamines are drugs that bind and block histamine receptors, thus alleviating allergy symptoms. These medications work by preventing histamines that have been released from mast cells from stimulating the itching and swelling of body tissues. H₁-antihistamines specifically target histamine H₁ receptors, which are found in mast cells, muscle, and endothelium, and are commonly used to treat reactions such as itching, runny nose, sneezing, insomnia, motion sickness, or vertigo. On the other hand, H₂-antihistamines bind to histamine H₂ receptors within the stomach to help manage gastric acid conditions like peptic ulcers and acid reflux.
Milder allergic reactions are often treated with antihistamines, which are available over-the-counter or by prescription. Alongside antihistamines, there are other drugs such as antileukotriene and antiprostaglandin medications that can be used in combined therapy for more effective treatment. Chronic use of antihistamines may require medical consultation to address potential health risks.