TOPICS: H-1 blockers, first generation H1 blockers, blood brain barrier, more side effects, diphenhydramine, chlorpheniramine, dimenhydrinate, doxylamine, treat allergies, motion sickness, sleep aid, sedation, antimuscarinic effects, anti alpha adrenergic effects, hypotension, tachycardia, second generation H1 blockers, loratadine, fexofenadine, desloratadine, cetirizine, treat allergies, less sedating