LIFE SCIENCE

Detailed explanation-1: -Diphenhydramine is a first-generation H1-antihistamine, a class of drugs that works by binding and stabilizing the H1-histamine receptor. It is found in a variety of allergy, cold, and sleep medications, with Benadryl as the best-known product.

Detailed explanation-2: -First-generation antihistamines were introduced in the 1940s and are still used today. These products work by affecting the histamine receptors in the brain and spinal cord. They go through the blood-brain barrier and can cause sleepiness. By contrast, second-generation antihistamines were first developed in the 1980s.

Detailed explanation-3: -Diphenhydramine, which is available as an over-the-counter medication, is a first-generation antihistamine that is used in a variety of conditions to treat and prevent dystonias, insomnia, pruritis, urticaria, vertigo, and motion sickness.

Detailed explanation-4: -First-generation antihistamines block both histaminic and muscarinic receptors as well as passing the blood-brain barrier. Second-generation antihistamines mainly block histaminic receptors and do not pass the blood-brain barrier.