Angiotensin-converting-enzyme inhibitors or ACE inhibitors are a class of pharmaceutical used primarily in the treatment of high blood pressure and weak heart muscle. They work by dilating blood vessels. The drugs were originally derived from pit viper venom.
As can be guessed by their name, ACE inhibitors work by suppressing ACE, which is part of the group of chemicals that regulate blood pressure in the body.
These drugs have moderate side effects including lowering blood pressure, cough, an increase in potassium, headache, dizziness, fatigue and nausea. More serious side effects include an effect on kidney function and must be avoided in patient's with pre-existing kidney conditions.