Pulmonary effects of topical timolol

Area of Science:

• Ophthalmology
• Pulmonology
• Pharmacology

Background:

• Timolol, a beta-adrenergic blocking agent, is a new topical treatment for glaucoma.
• Glaucoma management often involves topical medications.
• Asthma is a chronic respiratory condition characterized by airway inflammation.

Observation:

• A previously asymptomatic asthma patient experienced acute bronchospasm after using topical timolol.
• The patient's asthma symptoms resolved upon discontinuation of timolol.
• A controlled rechallenge with topical timolol reproduced the bronchospastic reaction.

Findings:

• Topical timolol administration led to a significant decrease in forced expiratory volume at one second (FEV1).
• A 25% FEV1 reduction occurred after two drops, and a 47% reduction after four drops.
• The bronchospastic response was dose-dependent.

Implications:

• Topical beta-adrenergic blocking agents like timolol should be avoided in patients with a history of asthma.
• Ophthalmologists and pulmonologists should be aware of this potential adverse drug reaction.
• Careful patient selection and monitoring are crucial when prescribing topical glaucoma medications.