New Drugs and Devices for Hypertension
Treatment for many medical conditions requires taking several pills daily – at best, an inconvenience. For example, of the 65 million Americans who have high blood pressure (hypertension), two-thirds require two or more anti-hypertensive drugs to manage their condition, according to a HealthDay report published 23 July. Among this patient group, many people also take drugs to help control high cholesterol and diabetes.
"Anybody can take a few drugs for a few months, but these people have to be on drugs indefinitely," Dr. John D. Bisognano reported to HealthDay. Dr. Bisognano is an associate professor of medicine and director of cardiac rehabilitation and clinical preventive cardiology at the University of Rochester Medical Center in Rochester, New York.
Fortunately, the situation with regard to multiple medications is changing, thanks to the ingenious efforts of several medical research companies that are developing drugs that are easier to take and devices that will help with long-term management of hypertension. Moreover, companies are focusing more acutely on prevention, so that children may be spared from developing hypertension.
Hypertension is a particularly risky condition, both because it often occurs without symptoms, and because it is a leading risk-factor for other severe conditions and events, including heart attack, stroke, kidney disease and heart failure. Taking a blood pressure reading is the only reliable way to determine the presence of hypertension.
Hypertension, or high blood pressure, is defined as <120 mmHg over <80 mmHg. A blood pressure reading equal to or greater than 140/90 mmHg is considered indicative of hypertension and requires medical intervention.
In 2003, the federal convened a panel entitled the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. In an effort to identify people at risk for hypertension, this panel created a new blood pressure category called "pre-hypertension". Pre-hypertension is defined as a pressure of 120-139/80-89 mmHg.
People diabetes or kidney disease are at very high risk for hypertension. In this population, the goal is to reduce patients’ blood pressure to 130/80 mmHg.
"One of the problems you run into is people who are at the highest risk – the people with diabetes and kidney disease – often require lots of medications to get their blood pressure down, because every medication gives you about a 10- to 15-point drop or so," Bisognano reported to HealthDay. "If you’re starting at 200 and need to go to 130, that’s a lot of medications."
New Anti-hypertensive Medications
Because no single medication has proved consistently to lower blood pressure, doctors often prescribe a range of drugs that may include angiotensin receptor blockers, diuretics, angiotensin-converting enzyme inhibitors, beta blockers and calcium-channel blockers.
Research drug companies recognize that there may be difficulty with compliance in patients required to take so many drugs. In response, these companies are developing new combination products. LeadDiscovery, a United Kingdom-based research company, predicts that, in the near future, fixed-dose combinations of antihypertensive drugs will be available, as well as drugs that may treat more than one risk factor at a time.
Leading the way, Pfizer Inc. was the first drug company to offer a combined antihypertensive product. In 2004, Pfizer received approval from the US Food and Drug Administration to market Caduet, a tablet containing Norvasc (amlodipine), for treating high blood pressure, and Lipitor (atorvastatin), for treating high cholesterol.
Other agents that hold promise include oral renin-inhibitors, a novel class of medications that target an enzyme released by the kidneys that can affect blood pressure. Of these new drugs, the first that is expected to be released is Aliskiren, a drug made by Novartis that is currently in phase III testing. LeadDiscovery report that analysts expect Novartis to seek regulatory approval in 2006, and they forecast sales over $1 billion by 2008, and over $3.6 billion by 2012.
And blood pressure technology research is keeping pace with drug development. For example, in March, University of Rochester Medical Center doctors were first to implant the “Rheos”, a battery-driven generator that activates the body’s natural regulatory systems for blood pressure. The device operates in a fashion similar to a pacemaker, which regulates heart rhythm. The Rheos device stimulates nerves in the carotid arteries to send a message to the brain to reduce blood pressure. Dr. Bisognano is one of the researchers testing the Rheos.
Source: New Hope for Those With High Blood Pressure, HealthDay, July 23, 2005.
Posted: July 2005