Final answer:
One side effect that might make a patient stop taking an ACEI is cough.
Step-by-step explanation:
One side effect that might make a patient stop taking an ACEI (angiotensin converting enzyme inhibitor) is cough. ACE inhibitors can cause a persistent, dry cough in some patients. This is thought to occur because ACE inhibitors increase levels of bradykinin, a hormone that can irritate the lungs and cause coughing. The cough can be so bothersome that patients may choose to discontinue the medication.