Examples
| Generic Name | Brand Name |
|---|
| apraclonidine hydrochloride | Iopidine |
| brimonidine tartrate | Alphagan |
| brimonidine tartrate and timolol maleate | Combigan |
| dipivefrin hydrochloride | Propine |
| epinephrine hydrochloride | Epifrin, Glaucon |
These medicines are given in eyedrop form. A commonly used
adrenergic agonist (brimonidine tartrate) eyedrop has a purple bottle cap. If
you need to use more than one type of eyedrop, you may need to take each
medicine in a certain order. You can use the color of the bottle cap to help
you remember when to use each type of eyedrop.
If you are using
more than one type of eyedrop, wait 5 minutes between the different eyedrop
medicines.
How It Works
Most adrenergic agonists reduce the
pressure in the eyes by reducing how much fluid (aqueous humor) the
eyes produce. They also increase the amount of fluid that drains out of the
eyes.
Why It Is Used
These medicines may be used along
with other medications to treat
glaucoma.
Apraclonidine and brimonidine
are used to treat high pressure in the eyes in people with
open-angle glaucoma. They are also used to prevent
high pressure in an eye after laser treatment for glaucoma. For everyday use,
brimonidine (Alphagan) is replacing apraclonidine (Iopidine) because it is less
likely to cause an allergic reaction. Some pharmacies no longer carry
apraclonidine eyedrops.
Dipivefrin is converted to epinephrine in
the body. Because newer adrenergic agonists are more effective and have fewer
side effects, dipivefrin is used only rarely.
Epinephrine is
rarely used since apraclonidine and brimonidine are just as effective with
fewer side effects.
How Well It Works
These medicines reduce the pressure
in the eyes. Reducing the pressure in the eyes reduces the chances of damage to
the optic nerve, preventing further vision loss.
Side Effects
Side effects of adrenergic agonists
include:
- Redness and stinging in the
eyes.
- Allergic reaction in the eyes (itching).
- Dry
mouth (very common with the newer medications but usually improves over
time).
- Drowsiness, nervousness, and headaches.
- Fast or
irregular heartbeat.
- Increased blood pressure.
Adrenergic agonists (especially epinephrine) may widen
(dilate) the pupil. This may trigger
closed-angle glaucoma in people who have narrow
drainage angles.
See Drug Reference for a
full list of side effects. (Drug Reference is not available in all
systems.)
What To Think About
Brimonidine should not be used if
a person is taking a monoamine oxidase inhibitor (MAOI), used to treat
depression. People who are taking tricyclic antidepressants and those with
severe heart, liver, or kidney disease may not be able to take this
medicine.
Epinephrine drops tighten (constrict) the blood vessels
on the eye's surface, taking the red out of the white part of the eye. After 2
to 3 hours, the vessels open (dilate) and the eye becomes red again. People may
be tempted to overuse this medicine to keep the red out of their eyes.
Apraclonidine and, less commonly, brimonidine may cause allergy problems
in some people when used over a long period of time.
These
medicines need to be used with caution in older adults and people who have
high blood pressure,
diabetes, an overactive thyroid gland (hyperthyroidism), or heart disease.
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