Side effect of Cyclopentolate when used in infants?

• A. Bradycardia (slow heart beat)
• B. Hypertension
• C. Tachycardia
• D. Hyperglycemia

Answer: (A)

Cyclopentolate is a potent antimuscarinic used to dilate the pupils. When infants absorb even small amounts systemically, they can show anticholinergic effects. In the heart, blocking parasympathetic (vagal) input removes slowing signals, so the heart rate tends to rise. This makes tachycardia the expected side effect in infants. Bradycardia would imply more parasympathetic activity, which is not how this drug works. While other systemic signs like irritability, fever, dry mouth, or flushed skin can occur, hypertension or hyperglycemia are not typical immediate effects from ophthalmic cyclopentolate in this context. So the side effect most consistent with its systemic action is tachycardia.