Autonomic Pharmacology USMLE Step 1 Practice Question

A 45-year-old woman with open-angle glaucoma presents to the ophthalmology clinic for a follow-up visit. She reports new-onset blurred vision and bilateral leg cramps that began 2 weeks after starting a new glaucoma medication. She denies headache, chest pain, or constitutional symptoms. Vital signs are stable: BP 128/82 mmHg, HR 72/min, RR 16/min, temperature 37°C, SpO2 98% on room air. Intraocular pressure (IOP) is measured at 18 mmHg (previously 24 mmHg). Slit lamp examination shows miosis bilaterally. The prescribed medication works by directly activating muscarinic receptors on ciliary muscle to increase aqueous humor outflow. Which of the following drugs was most likely prescribed?