Before taking perindopril, tell your doctor or pharmacist if you are allergic to it; or to other ACE inhibitors (such as captopril, lisinopril); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. 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, liver disease. This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis). Too much sweating, diarrhea, or vomiting may cause loss of too much body water (dehydration) and increase your risk of lightheadedness. Report prolonged diarrhea or vomiting to your doctor. Be sure to drink enough fluids to prevent dehydration unless your doctor directs you otherwise. This medication may increase your potassium levels. Before using potassium supplements or salt substitutes that contain potassium, consult your doctor or pharmacist. Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). Older adults may be more sensitive to the side effects of this drug, especially dizziness, high potassium levels, and rash. This medication is not recommended for use during pregnancy. It may harm an unborn baby. Consult your doctor for more details. See also Warning section. It is unknown if perindopril passes into breast milk. Consult your doctor before breast-feeding.