Telmisartan belongs to the angiotensin II receptor antagonists and is a long-acting antihypertensive drug. The antihypertensive effect becomes progressively more pronounced within 3 hours after the first dose, and the maximum antihypertensive effect is obtained in 4 weeks and can be maintained in long-term treatment. The drug is used in the treatment of essential hypertension. It is contraindicated in patients with hypersensitivity to the components of the product; during pregnancy and lactation; in patients with biliary obstructive diseases; in patients with severe hepatic insufficiency; in patients with severe renal dysfunction (creatinine clearance <30 ml/min). Adverse reactions include flu-like symptoms, dizziness, abdominal pain and diarrhea. So high blood pressure i.e. systolic blood pressure of 150mmHg cannot be lowered immediately by taking timosartan. The medication needs to be prescribed by the doctor.