Vasotec precautions. Before taking Vasotec, tell your doctor or pharmacist if you are allergic to it; or to other ACE inhibitors (such as benazepril); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Before using this medication, tell your doctor or pharmacist your medical history, especially of: history of an allergic reaction which included swelling of the face/lips/tongue/throat (angioedema), blood filtering procedures (such as LDL apheresis, dialysis), high level of potassium in the blood.