Antihistamines are considered first-line therapy for the relief of symptoms from allergic rhinitis and chronic urticaria. The newer, second-generation, nonsedating antihistamines reduce the central nervous system and anticholinergic side effects commonly found with previous drugs. The availability of H1-receptor antagonists that produce therapeutic effects without causing unwanted CNS effects fulfills an important practical need, since these drugs are clearly preferable in patients who drive or operate heavy machinery, or who are involved in activities requiring full alertness. Physicians and patients alike are pleased with the efficacy and safety the second-generation antihistamines bring to the treatment of allergy symptoms. Loratadine is an especially effective second-generation H1-receptor antagonist and is comparable to many of the other second-generation antihistamines. Loratadine may be particularly advantageous because of its low dose and the convenience of once-daily dosing. A more subtle advantage, loratadine's antiallergic properties, may warrant its use for specific treatment situations as future research clarifies the nature of the inflammatory response and the mechanisms of action antiallergic antagonists have in this regard.