Which long acting antihistamine is contraindicated for use in older adults?

The correct choice is cetirizine (Zyrtec), as it has specific considerations that make it less suitable for older adults. Cetirizine can cause sedation and drowsiness because it crosses the blood-brain barrier, which can be particularly concerning for older patients who may be more sensitive to such side effects. Sedation can increase the risk of falls and cognitive impairment in this population, making cetirizine a less ideal choice.

In contrast, loratadine (Claritin) and fexofenadine (Allegra) are classified as non-sedating antihistamines and are usually considered safer alternatives for older adults since they do not typically cross the blood-brain barrier, thereby minimizing the risk of sedation. Diphenhydramine (Benadryl), while effective as an antihistamine, is an older medication that is also sedating and has anticholinergic properties, which can lead to adverse effects in older populations, including dry mouth, constipation, urinary retention, and confusion. However, it is not the first choice typically recognized as contraindicated specifically for the same reasons as cetirizine.

Choosing cetirizine as contraindicated highlights the importance of considering the side effect profiles of medications in older adults