Repeated USMLE Questions Step 1- 184

A 77-year-old man presents to the emergency room with a complaint of retention of urine. Carbachol is administered to stimulate bladder emptying.

Which of the following is a prominent side effect of carbachol?

A-Tachycardia

B-Excessive salivation

C-Dry skin

D-Dilation of the pupils

E-Delirium

Answer







Carbachol is a cholinomimetic drug which activates acetylcholine receptors so, it is considered cholinergic drug. Cholinergic drugs in general enhance excessive salivation. Stimulation of cholinergic receptors lead to constriction of the pupils, a mechanism helps in glaucoma and as a preoperative drug before cataract surgery. It is also used as stimulant for bladder emptying in cases of urinary retention. It also results in excessive sweating and slow heart rate.

The correct answer is B