A 54-year-old woman has newly diagnosed primary open-angle glaucoma. She gives a history of moderate persistent bronchial asthma requiring occasional inhaler use. Which antiglaucoma drug should be avoided in her?

• A Timolol maleate ✓
• B Dorzolamide
• C Latanoprost
• D Latanoprostene bunod

Explanation

Timolol is a non-selective topical beta-blocker that reaches systemic circulation via nasolacrimal drainage and blocks airway beta-2 receptors, provoking severe bronchospasm in asthmatics. It is also avoided in patients with heart block, bradycardia and cardiac failure. Latanoprost, its derivative latanoprostene bunod and dorzolamide have no bronchoconstrictive effect and are acceptable alternatives. Nasolacrimal occlusion after instillation reduces but does not abolish systemic absorption of timolol.

Reference: Katzung's Basic and Clinical Pharmacology, 16th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.