Lose the allergy, not your alertness!

Abstract

Although histamine plays an important role in the brain (as neurotransmitter) and in the stomach (to aid digestion), its activity at H1 histamine receptors is involved in allergic reactions. When allergens invade the body, histamine is released and causes the small blood vessels to become more permeable leading to watery eyes, a runny nose, sneezing and nasal congestion. Antihistamines work to suppress the effects of histamine and decrease their symptoms. The second generation antihistamines have been developed to be more specific to H₁ receptors, thereby reducing the risk of adverse effects such as drowsiness and sedation. This article will discuss the second generation antihistamines in terms of their indications, risks and benefits.