Skip to main content Back to Top


Sedation a Factor with Newer Antihistamines

Katherine M. Bennett

New research suggests that not all second-generation antihistamines can really be called "nonsedating."

In a national study of general practitioners’ reports of patients’ adverse events, researchers in England compared the frequencies of links between sedation and loratadine, cetirizine, fexofenadine, and acrivastine soon after their availability in that country. The researchers collected information about 43,363 patients through questionnaires completed by the original prescribers three, six, or 12 months after a pharmacist filled the antihistamine prescription.

Although the risk of sedation was low with all four drugs, patients treated with acrivastine or cetirizine were roughly 3 times as likely as loratadine-treated patients to report sedation to their prescriber.

Because sedation can cause accidents and injuries, the researchers looked specifically at events reported during patients’ first month of treatment with each drug. There were no differences in risk for accidents and injuries.

The different levels of risks for sedation, the authors wrote, show that "fexofenadine and loratadine may be more appropriate for people working in safety critical jobs." To view the article in the April 29 issue of BMJ, go to