For years, people who have been troubled by both high blood pressure and diabetic kidney problems have believed that the more expensive blood pressure medications gave them an added benefit in the form of protection for their kidneys. So, they tended to spend extra dollars on expensive blood pressure medications even though cheaper generic equivalents were available. The less expensive generics, they were being told by their doctors, did less to help keep their kidneys healthy.

But a recent study on blood pressure medications and their relationship to kidney health has cast doubt on conventional wisdom.

The study, conducted in the United Kingdom, suggests that the more expensive blood pressure medications offer no more benefit to the kidneys than the less expensive generics. The real key, the study seems to say, is finding a medication that brings blood pressure down.

Dr. Raymond MacAllister at the Centre for Clinical Pharmacology at University College in London was quoted by HealthDay Reporter as saying, "In patients with high blood pressure who are at risk of progressive kidney disease -- particularly diabetics -- it doesn't matter which blood pressure drug you use, provided you get good control of the blood pressure."

The current guidelines for treating blood pressure in patients with kidney disease, especially diabetics, calls for the use of two types of drugs -- angiotensin-converting-enzyme (ACE) inhibitors and angiotensin-II receptor blockers (ARB). These are considered to be first-line medications to help lower blood pressure in those who have diabetic kidney disease. For several years, medical professionals have assumed that these drugs have specific protective effects for the kidneys, beyond their ability to lower blood pressure.

But the study done my MacAllister's group and published in the December 10, 2005 issue of The Lancet questions such assumptions.

The British team looked at evidence supporting the use of ACE inhibitors and ARBs as first-line treatment for patients with kidney disease. They reviewed and examined results from 127 trials that investigated blood pressure-lowering drugs on the progression of kidney disease.

They found that ACE inhibitors and ARBs fared no better than other blood pressure-lowering drugs in preventing diabetic kidney disease. It was also unclear if these two drug classes were more effective in patients with non diabetic kidney disease.

McAllister also noted that the study would not come as welcome news to some pharmaceutical companies.

But it will certainly please consumers who are already strapped and struggling with the high cost of blood pressure and kidney disease medications.