Classics in Chemical Neuroscience: Deliriant Antihistaminic\nDrugs

Antihistaminic\ndrugs are widely used clinically and have long been\nprimarily known for their use to treat severe allergic conditions\ncaused by histamine release. Antihistaminic drugs also exert central\nnervous system (CNS) effects, acting as anxiolytics, hypnotics, and\nneuroleptics. However, these drugs also have multiple serious neuropharmacological\nside-effects, inducing delirium, hyperarousal, disorganized behavior,\nand hallucinations. Due to their robust CNS effects, antihistamines\nare also increasingly abused, with occasional overdoses and life-threatening\ntoxicity. Here, we discuss chemical and neuropharmacological aspects\nof antihistaminic drugs in both human and animal (experimental) models\nand outline their current societal and mental health importance as\nneuroactive substances.