People who take blood pressure medications may not realize how unscientific doctors have been in their approach to finding the right drug or drugs for their condition -- in fact, the expression, "Throw enough mud at the wall and some is bound to stick," seems an apt description. Commonly, drugs for hypertension are prescribed on top of others in the hope that the growing pile will keep blood pressure under control. As a result, many patients end up taking three or even more different drugs daily to manage their blood pressure. Drugs arent the only tool that people can use to get blood pressure under control, of course. Many patients find that losing weight, exercising and making other lifestyle changes can do the trick. But for those who do require blood pressure medication, scientists have now developed a more precise method of predicting which drug will control hypertension in a particular individual -- and this could be very good news for drug-saturated blood pressure patients! ABCs of HBP Let me start by introducing you to renin, an enzyme produced by the kidneys that plays a critical role in modulating blood pressure. Renin regulates blood volume and vascular resistance as the bodys needs change -- but having too much renin is one cause of hypertension. Until recently, doctors have had no way to identify the patients in whom this is the root cause of the problem. Of the two types of drugs that treat hypertension, there is one category called "R" drugs (beta-blockers and ACE inhibitors) that works to control pressure by blocking the effect of blood renin levels. The other type, called "V" drugs (diuretics and calcium channel blockers), controls pressure by reducing blood volume. Since doctors have not had any easy techniques to help them determine whether a patient would benefit more from one or the other, some people with hypertension end up taking both types. For instance, they may take a pill that combines an R and a V drug along with another that is either an R or a V on its own. This new research may dramatically reduce the need for such guesswork. Better Than a Crystal Ball Done at the Albert Einstein College of Medicine of Yeshiva University , New York City, this new research was published in the August 2010 issue of the American Journal of Hypertension. Researchers measured renin levels in 945 previously untreated participants diagnosed with hypertension (a systolic, or top blood pressure, reading of at least 140 mmHg) before assigning them to either a V or R drug. A follow-up blood pressure reading was done one to three months later, and researchers found that the patients who had had high renin levels (more than 2.5 ng/mg/h) at the start of the study achieved better blood pressure control with an R drug, while those who had had low renin levels (below about 0.74 ng/mg/h) did better on a V drug. The conclusion -- renin levels can indeed be useful as a predictor of how a particular patient will respond to a particular type of blood pressure drug. A very important finding: For some patients, being on the wrong drug actually elevated their blood pressure, making the situation especially dangerous. The researchers found that 16% of patients with the lowest levels of renin who took an R drug experienced an increase of 10 or more points in their blood pressure. This rise, called a "pressor response," is not at all uncommon -- doctors have tended to assume it was caused by "noncompliance," blaming the patients for failing to take their medications. The study shows, though, that the pressor response often is caused by giving patients the wrong drug. Talk to Your Doctor I called the study author, Michael Alderman, MD, former president of the American Society of Hypertension. Based on these findings, Dr. Alderman said that he recommends that doctors measure renin levels in newly diagnosed hypertension patients as well as in those now taking multiple antihypertensive medications -- most particularly when the drugs dont seem to be helping. Dr. Alderman told me that it will likely be a few years before testing renin levels in advance of prescribing blood pressure medications becomes a standard practice, but he expects that it eventually will. If you need blood pressure medications, ask to have your renin level tested before you get a prescription -- trial and error is not the way you want to find out what works! Source(s): Michael H. Alderman, MD, former president of the American Society of Hypertension, professor of medicine at Albert Einstein College of Medicine of Yeshiva University , the Bronx, New York .