What medications can cause bilateral large pupils that are reactive to light?

From the Guidelines

Bilateral large pupils reactive to light can be caused by medications with anticholinergic or adrenergic effects, such as anticholinergics, sympathomimetics, certain antidepressants, and antipsychotics. These medications can block the parasympathetic nervous system or stimulate the sympathetic nervous system, leading to pupil dilation 1. Some common culprits include:

• Anticholinergic drugs like atropine, scopolamine, and tropicamide
• Sympathomimetic medications such as pseudoephedrine, phenylephrine, and amphetamines
• Certain antidepressants like tricyclics (amitriptyline)
• Some antipsychotics, such as phenothiazines 1
• Topical medications used in eye exams, such as mydriatic drops containing phenylephrine or tropicamide
• Recreational drugs including MDMA, cocaine, and LSD It's essential to note that these pupils often remain reactive to light, though the reaction may be sluggish compared to normal 1. If you notice unexplained pupillary changes, especially with symptoms like blurred vision, eye pain, or headache, seek medical attention as this could indicate medication side effects or other medical conditions requiring evaluation.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Causes of Bilateral Large Pupils Reactive to Light

• Bilateral large pupils reactive to light can be caused by various medications, including:
  • Anticholinergic agents such as glycopyrrolate 2 and scopolamine 3
  • Topical synthetic parasympatholytic agents 4
  • Atropine, scopolamine, and tropane alkaloids in all species of Datura plants 4
• These medications can cause mydriasis, which is the dilation of the pupils, by blocking the parasympathetic nervous system's control over the pupils 5

Mechanism of Action

• The parasympathetic nervous system controls the pupils' reaction to light, with the dorsal midbrain playing a major role in this process 5
• The sympathetic nervous system can also affect the pupils, but its role is more related to psychosensory reactions and the inhibition of the Edinger-Westphal nucleus 5
• The use of medications that block the parasympathetic nervous system can lead to impaired pupillary light reaction and mydriasis 5, 4

Diagnosis and Evaluation

• The diagnosis of bilateral large pupils reactive to light requires a stepwise evaluation, including a thorough medical history and physical examination 4
• Pharmacological testing with cocaine eye-drops can be helpful in distinguishing between physiological anisocoria and Horner's syndrome 5
• It is essential to consider the potential causes of mydriasis, including medication use, and to evaluate the patient's overall medical condition to determine the underlying cause of the symptoms 4, 3