CLARINASE REPETABS/Clarinase ER tab is contraindicated in those who have shown sensitivity or idiosyncrasy to their components, to adrenergic agents or to other drugs of similar chemical structure. CLARINASE REPETABS/Clarinase ER tab is also contraindicated in patients receiving MAO inhibitor therapy or within fourteen days of discontinuing such treatment and in patients with narrow angle glaucoma, urinary retention, severe hypertension, severe coronary artery disease and hyperthyroidism.