REDUCTION OF THE CENTRAL-NERVOUS-SYSTEM ADVERSE-EFFECTS ASSOCIATED WITH ANTIHISTAMINES IN THE MANAGEMENT OF ALLERGIC DISORDERS - STRATEGIESAND PROGRESS

To reduce the risks associated with the treatment of allergic disorder s, physicians should understand the benefits and risks of drugs in the antihistamine class. The risk of central nervous system adverse effec ts associated with antihistamine use is significant with the use of fi rst-generation antihistamines, which show pharmacologic activity in se rotonergic, alpha-adrenergic, dopaminergic, and muscarinic-cholinergic pathways. Adverse effects reported with the use of first-generation a ntihistamines most often include drowsiness, fatigue, and an inability to concentrate; these effects may result in decreased compliance with therapy. The second-generation antihistamines have the property of lo w lipid solubility, which slows access across the blood-brain barrier. The low sedative profile of these new drugs may also be linked to a m ore pronounced binding to peripheral rather than brain histamine H-1-r eceptors. The use of antihistamines with lower lipid solubility and gr eater specificity can provide an effective alternative for the relief of allergic symptoms, can improve compliance, and can reduce neurologi c side effects. Because of the differences now recognized in the side effects of drugs of this class, an individualized approach to selectio n of antihistamine therapy is required.