Brimonidine: What Is It For And How To Use It?
The active ingredient of brimonidine is used to reduce intraocular pressure (IOP). It is, therefore, indicated for patients with high eye fatigue and for the treatment of open-angle glaucoma.
Glaucoma is the main risk factor for ocular hypertension. The pressure inside the eye becomes so high that it can damage the optic nerve and cause irreversible and severe vision loss.
How does brimonidine work?
Brimonidine belongs to a class of medications called alpha-adrenergic agonists and works to decrease the amount of fluid inside the eye.
A substance that has similar or identical effects to adrenaline is called an adrenergic agonist. They are also known as sympathomimetic, that is, they act by imitating the sympathetic nervous system.
The sympathetic nervous system is one of the branches of the autonomic nervous system. He is responsible for performing involuntary functions such as:
- Dilation of the pupil.
- Decrease in saliva production.
- Increased heart rate.
- Inhibition of the activity of the digestive organs.
How should I use brimonidine?
Brimonidine can be found in solution in the form of eye drops and is administered by the ophthalmic route. In adult and elderly patients, the recommended dose is one drop in each affected eye twice a day, with an approximate interval of 12 hours between doses.
Instructions and recommendations for use
Attention: we should not use the medicine if the seal is broken before we start using it. It is important to wash your hands thoroughly before opening the bottle.
- To start, tilt your head back and look at the ceiling.
- Gently pull the lower eyelid down.
- Then turn the bottle upside down and squeeze until a drop of eye drops enter each affected eye.
- Close your eyes.
- To optimize use and avoid possible systemic absorption, it is advisable to press the lacrimal sac for one minute, right after each drop has been applied. In addition, if more than one ophthalmic medication is used, applications should be performed with an interval of 5 to 15 minutes between one medication and another.
- Once opened, the drug must be used within 28 days.
What are its adverse effects?
The most commonly reported adverse reactions are:
- Dry mouth.
- Ocular hyperemia.
- Burning and itchy eyes.
- Headache.
- Somnolence.
These are usually transient adverse effects that are less severe. Even so, it will be necessary to stop the treatment with brimonidine.
Among the rare side effects are:
- Corneal staining.
- Photophobia or light sensitivity.
- Eyelid edema.
- Asthenia.
- Rarely, palpitations or arrhythmia may occur.
If the following symptoms appear, contact your doctor immediately:
- Skin rashes.
- Difficulty breathing.
- Fainting.
- Dizziness.
- Nausea.
What are the contraindications?
Treatment with brimonidine is contraindicated in cases of:
- Hypersensitivity to the active substance or to any of the excipients.
- Newborns and children under 2 years old.
- Patients being treated with monoamine oxidase inhibitor (MAOI) antidepressant drugs.
- Patients treated with antidepressants that affect noradrenergic transmission (eg, tricyclic antidepressants).
Can I use brimonidine if I am pregnant?
There are animal studies that indicate that brimonidine does not cause teratogenic effects. However, studies carried out in rabbits, in which brimonidine levels were detected higher than those achieved during treatment in humans, showed a reduction in postnatal growth.
Although to date the safety of this medication during pregnancy in humans has not been clearly established, the use of brimonidine is not recommended during pregnancy.
Thus, it will only be considered if the possible benefit to the mother justifies the risk to the fetus. Its use is not recommended during the breastfeeding period.
