Livostin is the trade name of a prescription medication available in the Canada and the US.

It comes in the form of eye drops, and contains as an active ingredient the drug levocabastine. Levocabastine is an antihistamine which can be useful in relieving the itchy, watery eyes caused by allergies.

Most allergic reactions have to do with a chemical called histamine, which is something that your body produces naturally in response to foreign organisms in the environment. Some organisms - like those contained in pollen and pet hair - cause some people's bodies to produce too much histamine, which in turn irritates the eyes by causing them to become watery and itchy. Livostin can relive these symptoms by curbing your body's production of histamine, and by reducing the eye cells' sensitivity to it.

In order for it to be effective, Livostin must be used every day as directed by your doctor. It is also important that the eye drops be administered correctly. Many people don't know how to do this, which can make the medication much less effective.

There are a few important steps you should keep in mind when administering the drops:

1) Wash your hands. Your eyes are suffering from an allergic reaction, and it is therefore necessary to keep as many foreign organisms as possible away from them.

2) Tilt your head back, and press on the area just below your lower eyelid. This will create a small space between your eyeball and eyelid.

3) Drop the medication into this space and immediately close your eye for a minute or two. This allows the medication to be absorbed by the eyes. It is important that you don't blink.

4) Keep the applicator tip as sterile as possible. Do not let the tip touch your hands or eyeball, as this could contaminate it, and when finished, immediately replace the cap so that the applicator tip stays sterile.

As with all medication, it is possible that Livostin could interact dangerously with other drugs. It is therefore imperative that you notify your doctor of any other medication you are taking, or any allergies you have.

It is rare for Livostin to cause severe side effects: the most common one is an itching or burning sensation when the drops are placed in the eye - though for most people this will subside quickly.

If you find it doesn't you should consult your doctor immediately. Less common side effects include drowsiness and a dry mouth, and as with any side effect, if it persists or becomes uncomfortable you should consult your physician.