Expect a low level of postural hypotension at the start of ACEI treatment. Basically, your BP drops when you do a sudden standing from sitting or laying position. For that reason, ACEi are generally given at night when you don’t have to do much standing up. Not all people have that side effect, and even if you have it, it will only occur at the beginning few weeks of treatment. Afterwards your body will adjust to it. The other thing worth mentioning would be unexplained dry cough .