Valsartan effective against secondary hypertension in preschoolers

13 August 2008

MedWire News: Very young children with secondary hypertension can achieve reductions in blood pressure (BP) with use of valsartan, report researchers.

Joseph Flynn (Children's Hospital and Regional Medical Center, Seattle, Washington, USA) and team say that studies to date have focused on children older than 6 years, "leaving a significant information deficit regarding the treatment of hypertension in younger children, most of whom have underlying kidney disease or other secondary causes of hypertension."

The team recruited 90 children aged an average of 3.2 years who had systolic blood pressure at or above the 95th percentile. The children were randomly assigned in a 2:1:2 ratio to receive a low, medium, or high dose of valsartan, with the dose calculated according to weight.

During 2 weeks of treatment, children receiving valsartan achieved average systolic (S)BP and diastolic (D)BP reductions of about 8.5 and 5.7 mmHg, respectively. The reductions were statistically significant, but did not vary between treatment groups.

"Given its effects on angiotensin blockade, valsartan may also reduce proteinuria and have other beneficial effects in patients with underlying kidney disease," the researchers comment in the journal Hypertension.

The children were then randomly assigned to remain on valsartan or to switch to placebo for 2 weeks. After this phase, BP decreased further in children taking valsartan but rose again in those on placebo. The average BP difference between the two groups at this point was 3.9 mmHg (p=0.02) for SBP and 3.7 mmHg (p=0.009) for DBP.

During an additional open-label phase, all children were given valsartan with dose increases as necessary to achieve BP reductions. During this phase, 38 children received 20 mg valsartan, 24 required 40 mg, and 18 needed an 80-mg dose, while eight children were given additional hydrochlorothiazide. After 52 weeks, 77.3% of children had reduced their BP to below the 95th percentile.

Adverse events were recorded in up to 92% of the participants over the course of the trial. Most of these were common childhood ailments, such as cough, fever, upper respiratory infection, and diarrhea. No adverse event could be definitively linked to the study drug, including the four cases of elevated liver enzymes.

One child died, secondary to gastroenteritis, say Flynn et al. Again, this was not linked to the study drug, but the team says the case "highlights the risks of dehydration in children treated with antihypertensive drugs affecting the renin-angiotensin system and underscores the need for careful counseling and patient monitoring in children treated with such agents."

Finally, the children's height, body mass index, and head circumference remained in line with population norms throughout the trial.

"Although longer periods of study are clearly necessary, these data should provide clinicians with some reassurance regarding the effects of antihypertensive medications on growth and development," the researchers conclude.

Hypertension 2008; 52: 222-228