Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or other antihistamines (such as diphenhydramine, promethazine).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

Do not use with any other antihistamines applied to the skin (such as diphenhydramine cream, ointment, spray) because increased side effects may occur.

Hydroxyzine is very similar to cetirizine and levocetirizine. Do not use these medications while using hydroxyzine.

This medication may interfere with certain lab tests (such as allergy skin testing, urine corticosteroids level), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.