Sedating antihistamines cause sedation as they are highly lipid soluble and readily cross the blood brain barrier.
These drugs were extremely popular for this purpose until their propensity to build up in the body and produce toxic effects became known in the medical community.Inhalation sedation is also sometimes referred to as relative analgesia.Sedation is also used extensively in the intensive care unit so that patients who are being ventilated tolerate having an endotracheal tube in their trachea.Sedatives are a diverse group of drugs manufactured for medical purposes to relax the central nervous system.
Also known as tranquillizers or central nervous system (CNS) depressants, they encompass drug classes such as barbiturates, benzodiazepines, non-benzodiazepine sedative-hypnotics, anesthetics, antihistamines and opioid narcotics, as well as herbal compounds. Levocetirizine, the R-enantiomer of cetirizine, has been found to be less sedating relative to placebo than was cetirizine in separate trials. Bachert C, Bousquet J, Canonica GW, Durham SR, Klimek L, Mullol J, Van Cauwenberge PB, Van Hammée G; XPERT Study Group.