Can timolol (beta-blocker) eye drops affect blood pressure?

Timolol Eye Drops and Their Effect on Blood Pressure

Topical timolol eye drops can significantly affect blood pressure and cause systemic effects including bradycardia due to systemic absorption, despite their ophthalmic administration route. 1

Mechanism of Systemic Absorption

• Timolol maleate, a non-selective beta-blocker used in glaucoma treatment, can be absorbed into systemic circulation when applied topically to the eye 2
• Systemic absorption occurs primarily through the nasolacrimal drainage system, bypassing first-pass liver metabolism 3
• Peak plasma concentrations after eye drop administration occur rapidly, typically within 15 minutes of application 3

Cardiovascular Effects

• Topical timolol can cause significant systemic effects including bradycardia and reduced blood pressure 1
• Some patients with glaucoma requiring timolol treatment may even need pacemaker implantation due to severe bradycardia 1
• Mean arterial pressure can be significantly lowered for up to 4 hours after timolol eye drop application 4
• Plasma concentrations of timolol after ophthalmic application can reach levels high enough to induce systemic beta-blockade 4

Risk Factors for Increased Systemic Effects

• Elderly patients are at higher risk for systemic effects, especially when using both topical and systemic beta-blockers concurrently 1
• Patients with cerebrovascular insufficiency should use timolol with caution due to potential effects on blood pressure 2
• Patients with cardiac conditions such as sinus bradycardia, second or third-degree AV block, or cardiac failure should avoid timolol eye drops 2

Clinical Implications

• Concomitant use of topical timolol with oral beta-blockers should be monitored for potential additive effects on blood pressure and heart rate 2
• Caution is advised when using timolol eye drops with calcium antagonists due to possible atrioventricular conduction disturbances, left ventricular failure, and hypotension 2
• Patients using catecholamine-depleting drugs (e.g., reserpine) with timolol should be closely observed for possible additive effects resulting in hypotension and/or bradycardia 2

Methods to Reduce Systemic Absorption

• Nasolacrimal occlusion (pressing on the inner corner of the eye) for 5 minutes after application can significantly reduce systemic absorption of timolol 5
• The "tissue press method" is equally effective as nasolacrimal occlusion in reducing systemic absorption and is easier to administer 5
• Controlled-release delivery systems like ocular inserts can provide similar intraocular pressure reduction while producing lower peak plasma concentrations 3

Monitoring Recommendations

• Blood pressure and heart rate should be monitored in patients starting timolol eye drops, particularly in those with cardiovascular risk factors 2
• Patients should be advised about potential systemic effects and instructed to report symptoms such as dizziness, fatigue, or chest pain 2
• Consider alternative glaucoma treatments in patients with significant cardiovascular comorbidities 1