Web MD has tips for things you can do in your house to ease the sneezing and itchy eyes that are brought on by hay fever.
(A second type of antihistamine is used primarily for suppressing acid production in the stomach and treating acid-related diseases such as ulcers of the stomach.These antihistamines will not be discussed further.) Antihistamines also may be used to treat motion sickness, insomnia (difficulty sleeping), and anxiety.Fexofenadine is less well-studied and is rated FDA pregnancy category C.First generation antihistamines are usually used on an as-needed basis or before bedtime to occasionally help with sleep.The newer antihistamines (second generation) are less likely to cause these side effects. Long-acting antihistamines provide symptom relief for up to 8-12 hours, while shorter acting agents last for up to 4 hours but begin working faster.
First generation antihistamines are used less often to treat allergies because they cause significant sedation.Mild allergy symptoms include itchy, watery eyes, a runny nose, scratchy throat and a rash.More severe, life-threatening allergy symptoms include swelling of the throat, wheezing and difficulty breathing.Antihistamines are divided into two categories, first generation or older agents and second generation or newer agents.First generation antihistamines have many drawbacks including side effects of drowsiness and significant anticholinergic side effects that, for example, can cause difficulty urinating or constipation, and are therefore not used very often.Antihistamines work by blocking the effects of a chemical called histamine that is responsible for many allergic symptoms.