Study Compares Two Common Glaucoma Medications
A multinational study group including ophthalmologists from Finland, Germany, Ireland, Spain, and the United Kingdom recently reported the results of their study comparing Xalatan (latanoprost) and Alphagan (brimonidine) at the European Glaucoma Society meeting. The study group sought to determine both effectiveness and safety of the two commonly used glaucoma drops. Hannu Uusitalo, MD, ophthalmologist at the University Hospital, Tampere, Finland, presented the results.
The Study Protocol
A total of 379 patients with glaucoma or ocular hypertension (high eye pressure) were enrolled in the study and randomly assigned to receive one of the two drugs. The ophthalmologists were masked as to which agent individual patients were receiving to prevent observer bias. Baseline eye pressure measurements were taken prior to using the drops. The measurements were repeated at 2 weeks, 3 months, and 6 months after the patients had used the medication. Pressure readings were taken at 10:00 a.m. and 5:00 p.m. on examination days.
Adverse Events
Six months after the initiation of treatment, only 5 patients in the Xalatan group had withdrawn due to either side effects or uncontrolled eye pressure versus 53 patients in the Alphagan group. In the Alphagan group, 14 had ocular allergies to the medicine, 12 had uncontrolled eye pressure, and the remainder withdrew due to side effects or compliance related issues.
Effectiveness Controlling Eye Pressure
Patients in the Xalatan and Alphagan study groups had substantial decreases in eye pressure during the study; however, the group taking Xalatan had statistically significantly lower eye pressures than the Alphagan group. Those in the Xalatan group had a 28% reduction of eye pressure compared with a 21% reduction in the Alphagan group.
Furthermore, a target eye pressure of less than 18 mm Hg was achieved in 57% of the Xalatan patients versus 33% of the Alphagan patients. A pressure reduction of 30% or more was achieved in 42% of the Xalatan patients versus 22% of the Alphagan patients. Only 12% of the patients in the Xalatan group had a pressure reduction from baseline of less than 15%, compared to 32% of patients in the Alphagan group.
Conclusions
This study clearly shows Xalatan lowered intraocular pressure more effectively than Alphagan and had fewer side effects. Furthermore, since Xalatan only needs to be instilled once each day, patients may find it easier to use instead of Alphagan, which is used twice each day.
Despite the study results, patients should realize that glaucoma medications are tailored to the individual and the physician considers many factors when selecting the appropriate medication. This relatively short-term study did not assess the effect of treatment on the optic nerve or the peripheral vision with visual field testing, both key parameters when assessing treatment effect. Finally, as one can see from the above study results, the effect of glaucoma medication varies significantly from one individual to another, both in lowering pressure and side-effects. Therefore, it is certainly possible that Xalatan may be less effective than Alphagan in a given individual. This is why many ophthalmologists treat one eye initially, monitoring the effectiveness of the medication against the patient’s untreated eye.
What is Xalatan?
Xalatan reduces pressure in the eye by increasing the amount of fluid that drains from the eye.
Xalatan is used to treat certain types of glaucoma and other causes of high pressure inside the eye.
Xalatan may also be used for other purposes not listed in this medication guide.
Important information about Xalatan
Do not use Xalatan while you are wearing contact lenses. This medication may contain a preservative that can be absorbed by soft contact lenses. Wait at least 15 minutes after using Xalatan before putting your contact lenses in.
Xalatan may cause a gradual change in the color of your eyes or eyelids and lashes, as well as increased growth or thickness of your eyelashes. These color changes, usually an increase in brown pigment, occur slowly and you may not notice them for months or years. Color changes may be permanent even after your treatment ends, and may occur only in the eye being treated. This could result in a cosmetic difference in eye or eyelash color from one eye to the other.
Do not allow the dropper to touch any surface, including the eyes or hands. If the dropper becomes contaminated it could cause an infection in your eye, which can lead to vision loss or serious damage to the eye.
After using Xalatan, wait at least 5 minutes before using any other eye drops that your doctor has prescribed.
Before using Xalatan
Do not use Xalatan if you are allergic to latanoprost.
Before using Xalatan, tell your doctor if you are allergic to any drugs, or if you have swelling or infection of your eye.
Xalatan may cause a gradual change in the color of your eyes or eyelids and lashes, as well as increased growth or thickness of your eyelashes. These color changes, usually an increase in brown pigment, occur slowly and you may not notice them for months or years. Color changes may be permanent even after your treatment ends, and may occur only in the eye being treated. This could result in a cosmetic difference in eye or eyelash color from one eye to the other.
FDA pregnancy category C. This medication may be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. It is not known whether Xalatan passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.
How should I use Xalatan?
Do not use Xalatan while you are wearing contact lenses. This medication may contain a preservative that can be absorbed by soft contact lenses. Wait at least 15 minutes after using Xalatan before putting your contact lenses in.
Use this medication exactly as it was prescribed for you. Do not use the medication in larger amounts, or use it for longer than recommended by your doctor. Follow the instructions on your prescription label.
What is Alphagan?
Alphagan reduces the amount of fluid in the eye, which decreases pressure inside the eye.
Alphagan is used to treat open-angle glaucoma or ocular hypertension (high pressure inside the eye).
Alphagan may also be used for other purposes not listed in this medication guide.
What is the most important information I should know about Alphagan?
Do not use Alphagan if you have used an MAO inhibitor such as isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or tranylcypromine (Parnate) within the past 14 days.
Before using Alphagan, tell your doctor if you have kidney or liver disease, heart disease, high blood pressure, circulation problems such as Raynaud’s or Buerger’s disease, or a history of fainting or low blood pressure.
Do not use Alphagan while you are wearing contact lenses. This medication may contain a preservative that can be absorbed by soft contact lenses. Wait at least 15 minutes after using Alphagan before putting your contact lenses in.
Do not allow the dropper tip to touch any surface, including the eyes or hands. If the dropper becomes contaminated it could cause an infection in your eye, which can lead to vision loss or serious damage to the eye.
What should I discuss with my healthcare provider before using Alphagan?
You should not use Alphagan if you are allergic to brimonidine.
Do not use Alphagan if you have used an MAO inhibitor such as isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or tranylcypromine (Parnate) within the past 14 days.
Before using Alphagan, tell your doctor if you have:
- kidney disease;
- liver disease;
- heart disease or high blood pressure;
- circulation problems, such as Raynaud’s syndrome or Buerger’s disease; or
- a history of fainting or low blood pressure.
If you have any of these conditions, you may need a dose adjustment or special tests to safely use Alphagan.
FDA pregnancy category B. This medication is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. It is not known whether Alphagan passes into breast milk or if it could harm a nursing baby. Do not use Alphagan without telling your doctor if you are breast-feeding a baby.
How should I use Alphagan?
Use this medication exactly as prescribed by your doctor. Do not use it in larger amounts or for longer than recommended. Follow the directions on your prescription label.
Wash your hands before using the eye drops. Do not use Alphagan while you are wearing contact lenses. This medication may contain a preservative that can be absorbed by soft contact lenses. Wait at least 15 minutes after using Alphagan before putting your contact lenses in.
What can Xalatan do to the kidneys and liver?\ I have been taking Xalatan for 4 years and my doctor says my liver and kidney count is up?????? I am not currently taking any other drugs.
What does that mean????