WEDNESDAY, May 17 (HealthDay News) -- Two studies find that the new blood pressure drug aliskiren is effective in controlling high blood pressure, either alone or in combination with another common blood pressure drug.
Aliskiren is the first in a new class of drugs called renin inhibitors. Renin is an enzyme associated with regulation of circulation and blood pressure.
"This is the first new drug to treat hypertension in the last decade," said lead researcher Dr. Jerry Mitchell, from the Texas Center for Drug Development, in Houston.
"The benefits of blood pressure reduction are maximized if control is maintained continuously," which is what aliskiren appears to do, he said. Unlike most other blood pressure medications, which are taken twice a day, aliskiren is taken only once a day.
If left unchecked, "blood pressure variability is associated with damage to the heart, kidneys and brain," Mitchell noted.
The Houston researcher said scientists have long tried to find a drug that would act on renin, and this is the first one that has worked.
Aliskiren is not yet available, Mitchell said, but it has been submitted for approval by the U.S. Food and Drug Administration.
Both studies were presented Wednesday at the American Society of Hypertension annual meeting, in New York City.
In Mitchell's study, researchers looked at aliskiren's effect on lowering blood pressure over the course of a day.
In the study, 216 people with mild to moderate high blood pressure were randomly assigned to receive aliskiren at 150, 300 or 600 milligrams once a day, or placebo. Patients remained on their regimens for eight weeks.
Mitchell's team found that patients taking aliskiren achieved lower blood pressure compared with those taking the placebo. In addition, patients on aliskiren maintained a steady blood pressure without the usual spikes and dips in blood pressure seen in the morning and at night.
"There is no morning surge to hypertensive levels, it works throughout the 24-hour cycle," Mitchell said. "Aliskiren has the potential to maximize protection of the heart, kidneys and brain through continuous, smooth, blood pressure-lowering."
In the second study, a team led by Dr. Alberto Villamil, from Fundapres in Buenos Aires, Argentina, evaluated the efficacy and safety of aliskiren, alone and together with the diuretic hydrochlorothiazide.
Among nearly 2,800 patients with high blood pressure, the researchers found that aliskiren, when used by itself, significantly lowered blood pressure and, when used in combination with the diuretic, showed even greater reduction in blood pressure.
After eight weeks of treatment, patients who took aliskiren alone were able to lower their blood pressure by as much as 15.7 mm/Hg, while those taking both drugs were able to lower their blood pressure by as much as 21.2 mm/Hg, Villamil said.
"There is clearly a trend to obtain more important blood pressure reductions when we use the combination doses," Villamil said. In addition, more than 80 percent of the patients responded to the combination therapy, he added.
In addition, all the drug and dose combinations were well-tolerated and had the same side effects as patients receiving placebo, Villamil said.
One expert thinks the new drug is interesting, but he isn't sure how it is going to fit into blood pressure treatment.
"It's always interesting to have something new to work with," said Dr. Thomas Giles, president of the American Society of Hypertension.
"The principal question is, what will it bring to the table?" Giles, a professor of medicine at Tulane University, added. "At this point, that's a lot of conjecture."
It is not clear that aliskiren is any better than medications already available, Giles said. But he added that it may find use in combination with other blood pressure drugs, because most people need more than one drug to control their blood pressure.
"Patients will have access to another drug that has a very good side effect profile," Giles said. "That's always helpful. In addition, patients may be able to get drug combinations that are more effective."
"The true test is whether this drug will add anything to reducing organ damage and reducing morbidity and mortality," Giles said. "We don't know that yet."
Both studies were funded by Novartis Pharma AG, the maker of aliskiren.
For more on high blood pressure, head to the American Heart Association.