What is the dosage of brimonidine (alpha-2 adrenergic agonist) combined with timolol (beta-blocker) eye drops?

From the Guidelines

The recommended dosage for brimonidine/timolol combination eye drops is one drop in the affected eye(s) twice daily, approximately 12 hours apart, with a fixed combination of brimonidine tartrate 0.2% and timolol maleate 0.5%. This combination is often sold as Combigan and works by reducing aqueous humor production (timolol) and decreasing aqueous humor formation while increasing uveoscleral outflow (brimonidine), effectively lowering intraocular pressure through complementary mechanisms 1.

Administration Instructions

• Tilt your head back slightly and pull down your lower eyelid to create a small pocket
• Look up and place the drop into this pocket without touching the dropper to your eye or any surface
• After instillation, gently close your eyes for 1-2 minutes and press lightly on the inner corner of your eye to prevent drainage through the tear duct
• If using other eye drops, wait at least 5-10 minutes between different medications

Mechanism of Action

• Timolol reduces aqueous humor production
• Brimonidine decreases aqueous humor formation and increases uveoscleral outflow

Potential Side Effects

• Eye irritation, dryness, or redness
• Drowsiness from brimonidine absorption Although the evidence regarding the effectiveness of neuroprotective agents for slowing the progression of open angle glaucoma in adults is of low certainty, the combination of brimonidine and timolol has been shown to be effective in reducing intraocular pressure 1. A systematic review and network meta-analysis found that all active first-line drugs, including brimonidine and timolol, are effective compared to placebo in reducing intraocular pressure at 3 months 1.

From the Research

Dosage of Brimonidine Combined with Timolol Eye Drops

• The fixed combination of brimonidine tartrate 0.2% and timolol 0.5% is commonly used in the treatment of glaucoma and ocular hypertension 2, 3, 4, 5.
• This combination is typically administered twice daily (BID) 2, 3, 4, 5.
• Studies have shown that the fixed combination of brimonidine and timolol is as effective as concomitant use of the individual components in reducing intraocular pressure (IOP) 2.
• The mean reduction from baseline IOP with the fixed combination of brimonidine and timolol has been reported to range from 4.4 to 5.3 mmHg 2 and 4.4 to 7.6 mmHg 3 in different studies.
• The fixed combination of brimonidine and timolol has been shown to be well tolerated, with no unexpected side effects reported 2, 3, 4, 5.
• However, the incidence of treatment-related adverse events has been reported to be lower with the fixed combination compared to brimonidine monotherapy, but higher compared to timolol monotherapy 3.

Efficacy and Safety

• The efficacy and safety of the fixed combination of brimonidine and timolol have been evaluated in several studies, including a 12-week study 2 and a 12-month study 3.
• These studies have demonstrated that the fixed combination of brimonidine and timolol is effective in reducing IOP and is well tolerated, with a favorable safety profile 2, 3, 4, 5.
• The fixed combination of brimonidine and timolol has been shown to provide sustained IOP lowering over a 12-month period, with a mean IOP reduction of 4.4 to 7.6 mmHg 3.

Comparison with Other Treatments

• The fixed combination of brimonidine and timolol has been compared to other treatments, including brimonidine monotherapy and timolol monotherapy 3.
• Studies have shown that the fixed combination of brimonidine and timolol is more effective than brimonidine monotherapy and timolol monotherapy in reducing IOP 3.
• However, the fixed combination of brimonidine and timolol has been reported to have a higher incidence of treatment-related adverse events compared to timolol monotherapy 3.