Drug May Treat Advanced Kidney Disease
Chinese Study: Lotensin Showed Benefits Against Advanced Kidney Disease
Jan. 11, 2006 -- Doctors in China report that the blood pressure drug Lotensin may help patients with advanced chronic kidney disease.
The doctors write in The New England Journal of Medicine that patients taking Lotensin showed "substantial" kidney benefits.
In those patients -- none of whom had diabetes -- kidney disease progressed more slowly with Lotensin than their peers who took a placebo drug.
The study was done at Nanfang Hospital at Southern Medical University in Guangzhou, China. The hospital has a center for kidney disease care. The researchers included Fan Fan Hou, MD, PhD.
ACE Inhibitors and Kidney Disease
Lotensin is in a class of drugs called ACE inhibitors, which block an enzyme that constricts, or narrows, blood vessels. By doing so, they help lower blood pressure.
Kidney disease can develop over time in association with certain conditions such as high blood pressure and diabetes.
ACE inhibitors have already shown benefits to the kidney in people with mild or moderate kidney problems. Using the drugs to treat advanced kidney problems has been more controversial.
This is because ACE inhibitors can pose a potential threat to kidneys as well. The key question was whether damaged kidneys would worsen if patients took ACE inhibitors.
In a nutshell, concerns centered on blood levels of potassium and creatinine, waste products that are excreted by the kidneys. Testing creatinine levels in the blood is used as a way to monitor kidney function.
Taking ACE inhibitors can boost blood levels of potassium and creatinine, which would signify worsening kidney function.
Would that push damaged kidneys over the edge? That's what the Chinese researchers asked.
Hou's study included 422 people with advanced chronic kidney disease. None of the patients had diabetes. Some also took other drugs to control their blood pressure.
For more than three years, patients either took a placebo or 10 milligrams of Lotensin twice daily. Kidney problems worsened more slowly in those taking Lotensin. Overall, there were no major differences in side effects between patients taking Lotensin or the placebo.
Blood pressure, kidney function, and potassium levels should be monitored in patients with kidney disease who take Lotensin, especially during the first two months that the drug is taken, write the researchers.
When are ACE inhibitors no longer appropriate for people with advanced kidney disease? Hou's study doesn't show that, notes Lee Hebert, MD, in a journal editorial.
Plus, the Chinese patients didn't eat much salt or protein, Hebert observes. The low-salt diet could push up potassium levels. With little protein, the Chinese diet was kinder to the kidneys than a typical Western diet, Hebert writes.
The drug's dose and twice-daily regimen also drew Hebert's attention. Hebert writes that if an ACE inhibitor is used by someone with kidney disease, the dose should be "conservative," at least at first, and used cautiously, perhaps once daily in the morning.
Hebert, who didn't work on Hou's study, is on staff at Ohio State University Medical Center in Columbus, Ohio.