Levocabastine (lee-voe-KAB-as-teen) is used to treat certain disorders of the eye caused by allergies. It works by preventing the effects of a substance called histamine, which is produced in certain cells in your eyes and which causes the allergic reaction.

Levocabastine is available only with your doctor's prescription, in the following dosage form:

Ophthalmic
• Ophthalmic suspension (eye drops) (U.S. and Canada)

In deciding to use a medicine, the risks of using the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For levocabastine, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to levocabastine. Also tell your health care professional if you are allergic to any other substances, such as preservatives.

Pregnancy—Levocabastine has not been studied in pregnant women. However, studies in animals have shown that levocabastine, when given in very high doses, causes birth defects. Before using this medicine, make sure your doctor knows if you are pregnant or if you may become pregnant.

Breast-feeding—Although levocabastine passes into the breast milk, it has not been reported to cause problems in nursing babies. However, be sure you have discussed the risks and benefits of the medicine with your doctor.

Children—Studies on this medicine have been done only in adult patients and there is no specific information comparing use of levocabastine in children up to 12 years of age with use in other age groups.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of levocabastine in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your health care professional if you are using any other prescription or nonprescription (over the-counter [OTC]) medicine.

To use the eye drops:

• First, wash your hands. Tilt the head back and, pressing your finger gently on the skin just beneath the lower eyelid, pull the lower eyelid away from the eye to make a space. Drop the medicine into this space. Let go of the eyelid and gently close the eyes. Do not blink. Keep the eyes closed for 1 or 2 minutes to allow the medicine to be absorbed by the eye.
• If you think you did not get the drop of medicine into your eye properly, use another drop.
• To keep the medicine as germ-free as possible, do not touch the applicator tip to any surface (including the eye). Also, keep the container tightly closed.

In order for this medicine to work properly, it must be used every day in regularly spaced doses as ordered by your doctor. A few days may pass before you begin to feel better.

Dosing—

The dose of levocabastine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average dose of levocabastine. If your dose is different, do not change it unless your doctor tells you to do so.

• For ophthalmic suspension (eye drops) dosage form:
  • For eye allergy:
    • Adults and children 12 years of age and older—Use one drop in each eye four times a day.
    • Children up to 12 years of age—Use and dose must be determined by your doctor.

Missed dose—

If you miss a dose of this medicine, use it as soon as possible. Then go back to your regular dosing schedule.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Keep the medicine from freezing. Do not refrigerate.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

If your symptoms do not improve within 3 days or if your condition becomes worse, check with your doctor.

After application of this medicine to the eye, occasional stinging or burning may occur.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• Less common
  • Headache 
• Rare
• Change in vision or trouble in seeing;  cough;  eye pain;  nausea ;  redness, tearing, discharge, or other eye irritation not present before therapy or becoming worse during therapy;  skin rash;  sore throat;  swelling of eyelids;  troubled breathing ;  unusual tiredness or weakness 

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Burning or stinging when medicine is applied 
• Less common
• Dry eyes;  dry mouth;  feeling sleepy 

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.