Eye Drops

Overview

Zaditor and Opcon-A are two popular products used for the relief of allergy symptoms affecting the eyes. In this article, we are going to look at each product, discuss the difference between the two and give a recommendation on what we believe is the best option for allergy sufferers.

Zaditor

Active Ingredient: Ketotifen

Zaditor ophthalmic drops contain the active ingredient ketotifen. Ketotifen is both an antihistamine and a mast cell stabilizer. While most are familiar with antihistamines, the term 'mast cell stabilizer' is less well known.

Mast cells, when degranulated (typically when exposed to an allergen), release substances (including histamine) that trigger allergy symptoms such as inflammation, redness and itching. The blocking of mast cell degranulation therefore prevents the release of histamine and prevents allergy symptoms from occurring. Mast cell stabilizers prevent mast cells from degranulation.

The most important attribute of Zaditor is the fact that it doesn't just treat allergy symptoms like most products on the market. Many products simply relieve redness or alleviate itching. Zaditor, being an antihistamine/mast cell stabilizer, prevent allergy symptoms from occurring in the first place. ​

Zaditor is a great option for those who knowingly suffer from allergies. As an example, if you are allergic to dogs and you are going to be coming in to contact with one, Zaditor is a great preventative product to use.

Zaditor is not the only product that contains ketotifen available over the counter. Alaway also contains ketotifen and can be used as a substitute if desired.

Opcon-A

Active Ingredients: Naphazoline; Pheniramine

Opcon-A contains two active ingredients, naphazoline and pheniramine.  Naphazoline is classified as a decongestant and works to decrease ocular inflammation in addition to redness. Pheniramine is an antihistamine, similar to the active ingredient in Zaditor (ketotifen) , although it is not a mast cell stabilizer. Since Opcon-A contains both a decongestant and an antihistamine, it is a good option for allergy prophylaxis as well as immediate treatment of allergy symptoms you may be experiencing.

There are a variety of products over the counter that are available that also contain naphazoline and pheniramine if Opcon-A is not available. Visine-A and Naphcon-A also contain the two ingredients.​​

Which Product Is Better For Allergies?​


Both Zaditor and Opcon-A are safe and effective medications for treating allergy symptoms of the eye. There have been no head to head studies pitting Zaditor and Opcon-A against each other, so there is not a definite winner in terms of which medication is more effective. 

In our opinion however, Zaditor is a better product to prevent allergy related symptoms since it works both as an antihistamine as well as a mast cell stabilizer. If you suffer from seasonal allergies, Zaditor is the product that most likely will do a better job of preventing allergy symptoms from occurring.

Opcon-A should also be fairly effective in preventing allergy symptoms. We recommend Opcon-A for those that are also trying to treat symptoms that are actively occurring since it contains the ocular decongestant.

Our recommendation therefore is to use Zaditor as a preventative/prophylaxis measure and to go with Opcon-A for treating symptoms as they occur.