Difference between Alphagan and Alphagan P

In 2001, it was announced by Allergan that a newer and equally effective version of Alphagan was being launched. This drug’s name was to be known as Alphagan P. Basically, it was seen in many quarters of the industry as a replacement the then existing Alphagan.

People were and are still quite curious to want to know the major difference between Alphagan and Alphagan P. For instance, are there any significant variations when it comes to each of this drug’s efficacy as an eye treatment?

These questions are answered right here.

What Is Alphagan?

Alphagan is also known as brimonidine, it belongs in the class of medications referred to as alpha-2 adrenalin receptor agonists. This drug is basically found in its eye drop form. It is used as a treatment medication of choice to reduce pressure in the eye for those patients suffering from open eye glaucoma.

In normal functional circumstances of the eye, fluid is usually and constantly formed and drained out of the eye. But in cases when the fluid does not drain as expected, there is some abnormal pressure that is placed on the eye.

Alphagan eye drops work by minimizing and releasing this pressure, to allow the eye to function optimally. Basically, the medication works in reducing the amount of fluid the eye produces; but it also helps in fluid flow out of the eye.

Alphagan vs Alphagan P

Alphagan is formulated with each of its 1ml of sterile ophthalmic solution containing 2mg, equivalent to 0.2% of what is known as brimonidine tartrate. It also comprises of non-medicinal ingredients such as benzalkonium chloride which acts as its preservative, and citric acid.

Other ingredients to be found in the eye drop solution include hydrochloric acid and sodium hydroxide, which is normally used to adjust the solution's pH. Other than that Alphagan contains polyvinyl alcohol, purified water, and sodium chloride; It also contains and sodium citrate.

Meanwhile, Alphagan P, as a newer version of Alphagan, contains 1.5mg equivalent to 0.15% of brimonidine tartrate in each 1mg of its sterile ophthalmic solution. The non-medicinal ingredients of Alphagan-P include stabilized oxychloro complex which works as the solution's preservative, sodium carboxymethyl cellulose, and boric acid.

It also contains sodium borate decahydrate and sodium chloride, Other ingredients that are equally useful for this eye drop include calcium chloride dihydrate and, magnesium chloride hexahydrate,

Finally, it is also topped up with potassium chloride, and purified water. Hydrochloric acid or sodium hydroxide that is also part of the eye drops is useful in adjusting the formulation's pH.

What Is The Dosage Of Alphagan P And Alphagan?

Alphagan 0.2% is prescribed as a one drop dose for adults for the affected eye. It is administered 2 times daily with 12 hours apart of each application. In normal conditions, this should then be morning and evening.

Alphagan –P eye drop medication is prescribed to the adult patient, to be administered as one drop, 3 times each day, with 8 hour apart of each application.

Who Should Not Use Alphagan Eye Medication?

Patients that present allergic reactions either to brimonidine or any of the ingredients found in the eye drops.


You should seek your optometrist’s approval and advice before using the medication so as to avoid any unwanted reactions.

Previous article Trintellix, Vortioxetine, Brintellix: What's The Difference?
Next article Chlorthalidone and Pregnancy