Before taking levocetirizine:

• tell your doctor and pharmacist if you are allergic to levocetirizine, cetirizine (Zyrtec), or any other medications.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: antidepressants; medications for anxiety, mental illness, or seizures; ritonavir (Norvir, in Kaletra); sedatives; sleeping pills; theophylline (Theochron, Theolair); and tranquilizers. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or ever have had kidney disease.
• tell your doctor if you are pregnant or plan to become pregnant. If you become pregnant while taking levocetirizine, call your doctor. Do not breast-feed while you are taking levocetirizine.
• you should know that levocetirizine may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.
• ask your doctor about the safe use of alcoholic beverages while you are taking levocetirizine. Alcohol can add to the drowsiness caused by this medication.

Levocetirizine may cause side effects.

Talk with your doctor if any of the following symptoms becomes severe or does not go away:

• sleepiness
• tiredness
• weakness
• sore throat
• dry mouth
• fever
• cough
• nosebleed

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:

• hives
• rash
• itching
• swelling of the arms, hands, feet, ankles, or lower legs

Levocetirizine may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the someone has collapsed, had a seizure, has trouble breathing, or can't be awakened, call 911 immediately.