Under what condition should an ACE inhibitor be discontinued?

An ACE inhibitor should be discontinued during pregnancy due to its potential teratogenic effects. These medications can cause serious harm to a developing fetus, especially during the second and third trimesters, leading to complications such as fetal renal impairment, hypotension, and even death. The risks associated with taking ACE inhibitors during pregnancy outweigh any potential benefits, making it crucial for healthcare providers to switch patients to safer alternatives for managing conditions like hypertension or heart failure.

While hyperkalemia, renal failure, and allergy to the medication are situations that may also warrant discontinuation of an ACE inhibitor, the specific risk of teratogenicity in pregnant individuals makes pregnancy a standout reason for stopping the medication immediately.