Antihistamine
The vast majority of marketed H-antihistamines are receptor antagonists and only a minority of marketed compounds are inverse agonists at the receptor. Clinically, H-antihistamines are used to treat allergic reactions and mast cell-related disorders. Sedation is a common side effect of H-antihistamines that readily cross the blood–brain barrier; some of these drugs, such as diphenhydramine and doxylamine, are therefore used to treat insomnia. H-antihistamines can also reduce inflammation, since the expression of NF-κB, the transcription factor the regulates inflammatory processes, is promoted by both the receptor's constitutive activity and agonist (i.e., histamine) binding at the H receptor.
Effects of long-term benzodiazepine use
The effects of long-term benzodiazepine use include drug dependence and neurotoxicity as well as the possibility of adverse effects on cognitive function, physical health, and mental health. Benzodiazepines are generally effective when used therapeutically in the short term, but even then the risk of dependency can be significantly high. Most of the problems associated with benzodiazepines result from their long-term use. There are significant physical, mental and social risks associated with the long-term use of benzodiazepines. Although anxiety can temporarily increase as a withdrawal symptom, there is evidence that a reduction or withdrawal from benzodiazepines can lead in the long run to a reduction in anxiety symptoms. Due to these increasing physical and mental symptoms from long-term use of benzodiazepines, slowly withdrawing from benzodiazepines is recommended for many long-term users. Not everyone, however, experiences problems with long-term use.