Brimonidine Tartrate 0.2% Eye Drops for Glaucoma: Dosage and Use
Brimonidine tartrate 0.2% ophthalmic solution should be administered as one drop in the affected eye(s) three times daily, approximately 8 hours apart, for the treatment of open-angle glaucoma or ocular hypertension. 1
Mechanism of Action and Efficacy
Brimonidine is a highly selective alpha-2 adrenergic receptor agonist that lowers intraocular pressure (IOP) through two mechanisms:
- Reducing aqueous humor production
- Increasing aqueous humor outflow via the uveoscleral pathway 2
Clinical studies have demonstrated that brimonidine 0.2% provides:
- Mean peak IOP reductions of 5.6-6.5 mmHg (20-27% reduction from baseline)
- Mean trough IOP reductions of 3.3-3.7 mmHg
- Sustained efficacy for long-term treatment without tachyphylaxis 3, 4
Administration Guidelines
When using brimonidine with other topical ophthalmic medications:
- Apply medications at least 5 minutes apart
- If using multiple medications, consider brimonidine's place in the treatment algorithm:
- Can be used as monotherapy
- Can be used as adjunctive therapy with other glaucoma medications 1
Important Considerations and Precautions
Pregnancy and Breastfeeding
- Brimonidine has FDA Pregnancy Category B rating (safer than most other glaucoma medications which are Category C) 5
- Brimonidine should not be used in breastfeeding mothers as it can cross the blood-brain barrier and cause apnea and somnolence in infants 5
Monitoring
- Regular follow-up is essential to monitor IOP control
- Some patients may experience diminished efficacy over time, requiring close monitoring 1
- Patients should be evaluated for:
- IOP response
- Visual field status
- Optic disc appearance
- Side effects 5
Common Side Effects
- Oral dryness (reported in up to 33% of patients)
- Ocular hyperemia (11-26% of patients)
- Burning/stinging sensation (24-28% of patients)
- Allergic reactions (9-11% of patients) 2, 3, 6
Patient Education Points
- Instruct patients on proper eye drop instillation technique
- Emphasize the importance of adherence to the three-times-daily dosing schedule
- Advise patients to report any significant side effects, particularly allergic reactions
- Inform patients that maximum IOP-lowering effect typically occurs 2-3 hours after administration 4
Treatment Alternatives
If brimonidine is not tolerated or contraindicated:
- Laser trabeculoplasty may be considered as an alternative to medication
- Other medication classes (beta-blockers, prostaglandin analogs, carbonic anhydrase inhibitors) may be appropriate alternatives depending on patient factors 5