What is a key difference between prostaglandin analogs and beta-blockers in systemic effects?

• A. Prostaglandin analogs have minimal systemic effects; beta-blockers can cause systemic bradycardia and bronchospasm.
• B. Prostaglandin analogs cause severe systemic hypotension; beta-blockers have no systemic effects.
• C. They have identical systemic effects.
• D. Prostaglandin analogs cause respiratory distress; beta-blockers raise blood pressure.

Answer: (A)

The main idea is how much systemic exposure these eye-drop medications have. Prostaglandin analogs used for glaucoma primarily act locally in the eye to increase outflow, and when given as drops they have very limited systemic absorption, so systemic side effects are minimal. In contrast, beta-blockers used as eye drops can still enter the bloodstream in small amounts and block beta receptors throughout the body. This can lead to systemic bradycardia and bronchospasm from beta-2 blockade in the lungs, especially in people with asthma or COPD. So, prostaglandin analogs tend to have minimal systemic effects, while beta-blockers can cause systemic cardiovascular and respiratory effects.