Pazeo is a prescription eye drop used to treat itchy eyes caused by allergies. Its active ingredient is olopatadine hydrochloride at a 0.7% concentration, making it the strongest formulation in its family of allergy eye drops. The FDA approved Pazeo on January 30, 2015, and it requires just one drop per affected eye, once a day.
How Pazeo Works
Pazeo tackles allergic eye itch through two mechanisms at once. First, it blocks histamine receptors on the surface of the eye. Histamine is the chemical your immune system releases when it encounters an allergen like pollen or pet dander, and it’s directly responsible for the itching sensation. By blocking histamine’s landing sites, olopatadine prevents that itch signal from firing.
Second, it stabilizes mast cells. These are the immune cells that store and release histamine in the first place. By keeping mast cells from dumping their contents, Pazeo reduces the overall allergic response rather than just masking symptoms after they start. It also appears to calm eosinophils, another type of immune cell involved in allergic inflammation. This combination of blocking histamine and preventing its release is why olopatadine tends to work more broadly than eye drops that only do one or the other.
How Long the Relief Lasts
In clinical trials, Pazeo provided significant itch relief within 30 to 34 minutes of application. More notably, that relief held up at both the 16-hour and 24-hour marks after a single drop. This full-day duration is the key advantage of the 0.7% concentration and the reason Pazeo only needs to be used once daily. For people dealing with seasonal allergies, one drop in the morning can cover the entire day.
Dosing and How to Use It
The standard dose is one drop in each affected eye, once per day. Children aged 2 and older can use the same dose as adults. If you wear contact lenses, you should remove them before applying the drop. The preservative in the solution, benzalkonium chloride, can be absorbed by soft contacts and cause irritation. Wait at least 10 minutes after applying Pazeo before reinserting your lenses.
When applying the drop, tilt your head back, pull down your lower eyelid to create a small pocket, and let the drop fall in without touching the dropper tip to your eye or any other surface. This helps prevent contamination of the bottle.
Common Side Effects
Pazeo is generally well tolerated. The most commonly reported side effects in clinical trials were mild and localized: a bad taste in the mouth (the tear ducts drain into the nasal passages, so some of the drop can reach the back of the throat), blurred vision right after application, and mild eye irritation or discomfort at the site of the drop. These effects are typically brief and resolve on their own. Serious reactions are rare.
Pazeo vs. Pataday vs. Patanol
All three of these products contain the same active ingredient, olopatadine, but at different concentrations. Understanding the differences can save confusion at the pharmacy.
- Patanol (0.1%): The original formulation. It’s dosed twice daily and is indicated for both itching and redness. It’s now available over the counter as Pataday Twice Daily Relief.
- Pataday (0.2%): A stronger version that brought dosing down to once daily. It treats itching only. It’s now sold over the counter as Pataday Once Daily Relief.
- Pazeo (0.7%): The highest concentration. Also dosed once daily for itching. It was originally prescription-only.
The FDA has noted that the differences between these three formulations come down to dosing frequency, not fundamentally different effects. The twice-daily, lower-concentration version covers both itching and redness, while the once-daily formulations at higher concentrations are approved specifically for itch relief. For many people, the over-the-counter Pataday options work well enough. Pazeo at 0.7% is typically reserved for cases where a stronger, longer-lasting dose is needed or preferred.
Prescription vs. Over-the-Counter Access
When Pazeo launched in 2015, it was available only by prescription. The lower-strength olopatadine formulations (0.1% and 0.2%) have since moved to over-the-counter status under the Pataday brand name. Pazeo’s 0.7% concentration may still require a prescription depending on your location and insurance plan. If cost is a concern, asking your eye doctor whether the OTC Pataday Once Daily Relief (0.2%) would be sufficient for your symptoms is a reasonable starting point, since both use the same once-daily dosing schedule.