In children ages 6 or older with high blood pressure, losartan lowers blood pressure in a dose-dependent manner and is generally well tolerated across a wide range of doses, results of a new study show.

Dr. Shahnaz Shahinfar from Merck Research Laboratories in West Point, Pennsylvania and colleagues examined the dose-response relationship, as well as safety and tolerability, of once-daily losartan in 175 children between the ages of 6 and16 years old. The average blood pressure at the beginning of the study was approximately 130/89 mm Hg.

The children were classified by weight and randomly assigned to low-dose losartan (2.5 to 5.0 mg daily), middle-dose losartan (25 to 50 mg daily) or high-dose losartan (50 to 100 mg daily).

After 3 weeks changes in diastolic blood pressure - the lower blood pressure reading - in the low-, middle-, and high-dose groups were -6.0, -11.7, and -12.2 mm Hg, respectively, the investigators report in the American Journal of Hypertension.

Diastolic blood pressure increased significantly in children who switched from middle- and high-dose losartan to placebo compared with children who remained on active treatment, but it remained stable in patients who switched from low-dose losartan to placebo.

The investigators conclude that up to 50 mg once daily was an effective starting dose. Losartan doses up to 100 mg once daily were well tolerated.

Children with high blood pressure who do not respond to weight reduction, exercise, and diet, often require drug therapy, but clinical trials in children are lacking. This is the first study to provide substantial data on losartan in children with high blood pressure, the researchers note.

SOURCE: American Journal of Hypertension, February 2005.