High blood pressure, and the prevention of heart attack, stroke and cardiovascular death in adults with established atherosclerotic disease or high-risk diabetes.

Angiotensin II is a hormone that squeezes blood vessels tight and tells the kidneys to hold on to salt and water. Telmisartan occupies the receptor it acts through, so the vessels stay relaxed and the kidneys release more salt and water. Because it binds the receptor for a long time, one dose covers a full 24 hours.

Dizziness, especially at the start or on standing, back or joint pain, sinus symptoms, and a raised potassium level on blood tests. It does not usually cause the dry cough that ACE inhibitors can.

Telmisartan must not be used in pregnancy, as it can seriously harm the developing baby. Blood tests check kidney function and potassium, and potassium supplements or salt substitutes should be avoided unless your doctor agrees. Be careful with NSAIDs such as ibuprofen, and with dehydration from heat, vomiting or diarrhoea, both of which can strain the kidneys. It is a prescription medicine in Pakistan.