What drugs cause pupillary dilation?

Drugs That Cause Pupillary Dilation

Anticholinergic medications are the primary class of drugs that cause pupillary dilation, with adrenergic agents being another significant category. 1

Anticholinergic Medications

• Scopolamine causes pupillary dilation with side effects including blurred vision, dry mouth, and urinary retention 1, 2
• Tropicamide (ophthalmic drops) causes significant pupillary dilation and is commonly used for eye examinations 3
• Cyclopentolate (ophthalmic drops) causes stronger and longer-lasting pupillary dilation than tropicamide 3
• Atropine (both systemic and ophthalmic) causes pupillary dilation, though intravenous atropine at doses used in dobutamine stress echocardiography (0.25-0.75 mg) may not significantly affect pupil size in adults without glaucoma 4, 5
• Other anticholinergic medications including tricyclic antidepressants and certain psychiatric medications can cause pupillary dilation 1, 6

Adrenergic/Sympathomimetic Agents

• Phenylephrine (ophthalmic drops) causes pupillary dilation through direct sympathomimetic action 6, 3
• Epinephrine (systemic) can cause pupillary dilation, particularly when used for anaphylactic shock 6
• Nasal decongestants containing ephedrine can cause pupillary dilation 6
• Nebulized salbutamol (albuterol) has been reported to cause pupillary dilation 6

Clinical Implications

• Pupillary dilation from these medications can precipitate acute angle-closure glaucoma in susceptible individuals with narrow iridocorneal angles 1, 6
• The mydriatic effect of scopolamine specifically may increase intraocular pressure resulting in acute angle closure glaucoma 2
• Patients with primary angle-closure suspect (PACS) should be warned about the risk of using medications that cause pupillary dilation 1
• Symptoms of acute angle closure glaucoma include eye pain, blurred vision, visual halos, and red eyes 2

Risk Assessment and Precautions

• High-risk eyes (those with narrow angles) should never be dilated with cyclopentolate due to higher risk of angle closure 3
• Tropicamide is generally safer but still requires precautions in patients with narrow angles 3
• Phenylephrine-induced mydriasis followed by miosis with thymoxamine drops is considered safest for high-risk patients 3
• Patients with known narrow angles should be monitored for intraocular pressure changes when receiving medications with mydriatic effects 6

Monitoring and Management

• Monitor intraocular pressure in patients with open-angle glaucoma when using medications with mydriatic effects 2
• Advise patients to immediately discontinue medications and seek medical attention if they experience symptoms of acute angle closure 2
• Treatment of medication-induced angle closure typically includes intravenous acetazolamide and pilocarpine to rapidly normalize pressure 3
• For patients requiring diagnostic pupillary dilation who are at risk for angle closure, ophthalmology consultation should be considered before administration 6, 3