What Is Hydroxyzine HCL?

Hydroxyzine HCL is an antihistamine that treats itching caused by allergies, states WebMD. It can also be used to relax an individual before and after surgery and to treat anxiety.

Hydroxyzine HCL is taken by mouth typically three or four times a day, notes WebMD. Dosage depends on weight, medical condition, age and response to treatment. A special measuring spoon should be used for the liquid form of hydroxyzine HCL instead of a household spoon to ensure proper dosage.

Common side effects of hydroxyzine HCL include drowsiness, constipation, dry mouth, blurred vision and dizziness. Serious side effects include tremors, an altered heartbeat, difficulty urinating, mental changes and seizures. Serious allergic reactions to hydroxyzine HCL are rare.

Patients should inform their doctor or pharmacist about allergies to cetirizine or levocetirizine before taking hydroxyzine HCL, warns WebMD. Individuals with liver disease, diabetes or any condition that requires limited sugar and alcohol intake should take precaution when taking hydroxyzine HCL. Older adults are at a higher risk for experiencing constipation, drowsiness, trouble urinating and confusion when taking this medicine. Hydroxyzine HCL should not be taken along with cetirizine, levocetirizine and other antihistamines applied to the skin, and this medicine may cause false laboratory test results.