What should patients be advised regarding the side effects of hydroxyzine?

Hydroxyzine is an antihistamine with sedative properties, commonly used as an anxiolytic and antiemetic. One of the primary side effects of hydroxyzine is drowsiness. This effect occurs because hydroxyzine crosses the blood-brain barrier and interacts with histamine receptors in the central nervous system, leading to sedation. Patients should be advised of this side effect to ensure they understand the potential impact on activities that require full alertness, such as driving or operating machinery. Recognizing drowsiness as a common side effect allows patients to manage their expectations and take precautions.