Irbersatan, an orally active antihypertensive agent, effectively reduce blood pressure by directly blocking angiotensin II receptors without any significant adverse effects. The purpose of this study is to evaluate the efficacy and safety of irbesartan in patients with mild to moderate hypertension.

This study enrolled 83 patients who had diastolic pressure above 95 mmHg and below 110 mmHg on two measurements. Sixty eight patients were administered 150mg of irbesartan, an angiotensin II receptor blocker, daily for four weeks as an initial dosage. If the sitting diastolic pressure was equal to or greater than 90 mmHg after a 4 week treatment period, the dosage was doubled until the end of 8 weeks. Baseline pressures, antihypertensive effect, side effects, laboratory findings were compared before and after treatment.

Fourty two patients out of 53 patients having completed this study showed decreased blood pressure equal to or more than 5 mmHg of the sitting diastolic pressure (response rate=79%). Twenty one patients out of 53 patients showed normalized blood pressure below 90 mmHg of the sitting diastolic pressure (normalization rate=40%). The extent of decrease in diastolic and systolic blood pressure after eight week treatment was an average 11.7±10.1 mmHg and 16.3±18.9 mmHg, respectively (p<0.05). Nineteen ontoward side effects was observed in 17 patients out of 68 patients with medication (frequency of ontoward effects=25%). Only one case with headache was considered to be related to the medication. Abnormal laboratory findings were observed in eight patients, and only one case with elevation of bilirubin and ALT levels was considered to be related to the medication.

In conclusion, irbesartan is a safe and effective antihypertensive drug in patients with mild to moderate hypertension with tolerable side effects.