3. Phenylephrine hydrochloride.

Phenylephrine hydrochloride is a potent, effective, relatively safe drug with few ocular side effects. Side effects from topical instillation are uncommon but include severe systemic cardiovascular effects with elevated blood pressure and stroke. Ten percent phenylephrine should be used with caution in patients with known cardiac disease, hypertension, aneurysms, long-standing insulin-dependent diabetes, or advanced arteriosclerosis. A 2.5% concentration is generally indicated for ophthalmic examination as well as for use in infants and in the elderly. Phenylephrine should not be used in patients with narrow-angle glaucoma, and it is also contraindicated in patients taking monoamine oxidase inhibitors or tricyclic antidepressants.