Why does zestril (lisinopril) sometimes cause coughing? would the cough be constant or intermittent?

ACE inhibition.: There is an enzyme in your lungs called angiotensin converting enzyme. It is inhibited by zestril (lisinopril). As a result there is a local accumulation of products (possibly kinins, substance p and thromboxane) that triggers cough. The cough is intermittent and nonproductive - some describe a tickle like cough.

Histamine related : Zestril (lisinopril) is an ace inhibitor and in addition is a bradykinase inhibitor. This means it prevents the breakdown of bradykinnins. Bradykinnins cause increases in histamine levels. This increase in histamine likely causes the cough. The cough may constant or intermittent and typically is of the dry/hairball variety.

ACE-I's and cough: Ace-inhibitors (ace-i) are well known to cough. Having said that, there are other causes of cough in patients who take them and are unrelated to them. If you have a cough you think is due to an ace-i, stop it for two days. If you still have the cough after 2 days, it is not due to the ace-i. Call your physician to discuss some other things that can cause a cough. One of them is esophageal reflux.