Timolol-induced interstitial lung disease

Timolol maleate is a non-selective beta-adrenergic receptor blocking agent with demonstrated efficacy in the treatment of open-angle glaucoma. A 76 year old female who presented with productive cough, progressive dyspnea and hypoxia after starting timolol maleate opthalamic drops following glaucoma surgery. The patient was diagnosed with interstitial lung disease secondary to timolol treatment and after cessation of the offending agent along with corticosteroid treatment, symptoms improved drastically. Elimination of other possible causes of disease along with evolution of radiological and functional signs left us with a diagnosis of timolol-induced interstitial lung disease. To our knowledge, this is the second reported case of timolol-induced interstitial lung disease.