Zyrtec and Claritin have very few side effects and are generally recognized as safe for most people. Zyrtec can cause sleepiness, but only in some people.Take it for the first time when you will be at home for a few hours in case it makes you sleepy.Although nausea is the hallmark symptom, it is often preceded by stomach awareness, malaise, drowsiness, and irritability.Early self-diagnosis should be emphasized, and patients should be counseled about behavioral and pharmacologic strategies to prevent motion sickness before traveling.
Clinicians should ask caregivers about use of nonprescription cough and cold preparations to avoid overdosage.
Histamine produces increased vascular permeability, causing fluid to escape from capillaries into tissues, which leads to the classic symptoms of an allergic reaction — a runny nose and watery eyes. Antihistamines suppress the histamine-induced wheal response (swelling) and flare response (vasodilation) by blocking the binding of histamine to its receptors or reducing histamine receptor activity on nerves, vascular smooth muscle, glandular cells, endothelium, and mast cells.
Itching, sneezing, and inflammatory responses are suppressed by antihistamines that act on H1-receptors.
-receptor are used to treat allergic reactions in the nose (e.g., itching, runny nose, and sneezing) as well as for insomnia.
They are sometimes also used to treat motion sickness or vertigo caused by problems with the inner ear.