Olopatadine is a prescription antihistamine medication. It is primarily used to treat conjunctivitis, more commonly known as pink eye, which is usually caused by allergies or an infection, but it can also be used for other symptoms of allergies such as runny nose, sneezing, and itchiness. The drug is most commonly distributed as eye drops, but also comes in nasal spray and tablet form. Olopatadine is marketed under the brand names Patanol®, Patanase® and Allelock®.
The drug works by blocking histamine, a chemical in the body which causes the symptoms related to allergic reactions. Olopatadine specifically does this by activating the H1-receptor antagonist which holds off release of the chemical. It also works to stabilize mast cells, which have high histamine content.
Olopatadine can come in eye drop form, usually distributed under the brand name Patanol®. While using the drops, patients are typically advised to avoid wearing contact lenses if their eyes are red. Once the redness has subsided, many doctors recommend waiting several minutes after applying the drops before inserting lenses.
The drug is also available as the nasal spray Patanase®. This kind of Olopatadine targets nasal problems, itching, and sneezing. Doctors typically recommend blowing the nose before administering the spray and abstaining from clearing the nose or sneezing for several minutes after spraying.
Allelock® is a tablet form of the drug. It is primarily distributed in Japan. In addition to targeting many of the same nasal and sneezing symptoms that the nasal spray does, it also treats skin diseases such as dermatitis and eczema. It is typically prescribed to be taken two times a day.
Most of the side effects of olopatadine do not commonly present themselves and tend to be mild. Some common symptoms of the eye drops include burning, blurring, dryness, or stinging in the eyes. Nasal spray users may experience diarrhea or nausea. With any form of the drug, a patient may also get a sore throat, headache, or experience a change in taste. These side effects should only be reported to a doctor if they become more serious or do not eventually go away.
Severe side effects from taking olopatadine are rare and should receive immediate medical attention. Irritation, drainage, and crusting of the eyes are all serious symptoms. Redness, swelling, or intense burning in the eyes should also be treated as soon as possible. An allergic reaction should receive emergency medical attention. Symptoms include breathing problems, swelling in the areas from the neck up, and hives.