the difference between the first and second gens of histamine-1 blockers

first→-ine(diphENhydramINE, ☆chlorphENiramINE)
second→-adine(loratADINE)

First-generation antihistamines are considered potentially inappropriate medications for elderly patients, especially those with pre-existing cognitive or functional impairment.
☆nonspecific and act as an antagonists to multiple receptors including muscarinic acetylcholine receptor

second→ far less sedating
more specific to histamine H1 receptor

neurology pharmacology UWorld