How to tame stubbornly high blood pressure

Harvard Heart Letter

Resistant hypertension poses a serious threat to your heart's health.

About one in three American adults has high blood pressure, defined as a top (systolic) blood pressure reading of 140 or higher or a bottom (diastolic) reading of 90 or higher. Also known as hypertension, this often-symptomless condition is a leading cause of stroke and heart attack. The good news is that more people have their blood pressure under control than in years past. The bad news? Nearly 10 percent of people who've been prescribed multiple medications to treat their hypertension still have dangerously elevated blood pressure readings.

Defining resistant HTN

"When people have high blood pressure despite being on three different medications, including a thiazide diuretic, they have what's known as resistant hypertension," says Dr. Joshua Beckman, a cardiologist at Harvard-affiliated Brigham and Women's Hospital. (Thiazide diuretics are often the first drugs doctors prescribe for high blood pressure.)

Resistant hypertension is especially worrisome because the risk of death from heart attack and stroke rises in tandem with blood pressure. But pinpointing the underlying cause can be tricky. For instance, some people who appear to have resistant hypertension may have "white-coat hypertension," which refers to an abnormally high blood pressure reading in a medical setting. The problem is thought to result from stress or anxiety, which raises blood pressure. To rule this out, your doctor may recommend using a home blood pressure monitor, or send you home with a device that automatically takes your blood pressure every 15 to 30 minutes over a 24-hour period.

Some people with apparent resistant hypertension simply may not be taking their medicines. Dr. Beckman suspects this may be the reason for many cases of resistant hypertension, a conclusion he bases on his involvement in a major clinical trial to address the problem. In a group of people thought to have resistant hypertension, researchers compared an experimental catheter-based procedure with the standard drug therapy—in this case, a regimen of at least three blood pressure medications. "But once we got them in the study and following a closely tracked drug regimen, some of them no longer had resistant hypertension," says Dr. Beckman.

Blood pressure drugs: Many options and combinations

There are more than 200 different drugs to treat high blood pressure. They fall into several classes:

  • diuretics

  • ACE inhibitors and angiotensin-receptor blockers

  • calcium-channel blockers

  • beta blockers

  • aldosterone blockers.

Exactly which classes of blood pressure medications your doctor prescribes may depend on other medical conditions you have, such as angina or atrial fibrillation. Side effects can also limit which classes of medications are used. Many commonly prescribed drugs are available as generics. Combination medications pack two different classes into one pill, such as a diuretic with a beta blocker or an ACE inhibitor with a calcium-channel blocker.

Image: Thinkstock

Fewer drugs, more healthy habits

To help his patients stick to their medication schedules, Dr. Beckman lowers the number of daily pills they need to take. That's often easy because many common, generic blood pressure medications are available as combination pills. "Initially, doctors often prescribe single-ingredient medications because it's easier to adjust the dosage. But once you get to a certain dose on several drugs, it's better to switch to a combination drug," he says.

A number of other things can help lower blood pressure independent of medications. At the top of the list: lose weight if you're overweight, and get regular exercise. You should also take these steps:

  • Eat more potassium-rich fruits and vegetables. Potassium helps lower blood pressure. Good choices include tomatoes, spinach, sweet potatoes, avocados, dried apricots, bananas, oranges, and cantaloupe.

  • Avoid processed and restaurant-prepared foods. These foods can be loaded with sodium, which raises blood pressure. Common sources of extra sodium include cold cuts and cured meats, pizza, soups, sandwiches, and cheese.

  • Don't drink too much alcohol. Because alcohol raises blood pressure, have no more than two drinks per day if you're male, or one drink per day if you're female.

  • Check your over-the-counter medications. Common drugs can boost blood pressure, including painkillers such as ibuprofen (Advil, Motrin) and naproxen (Aleve, Anaprox) as well as cold and flu remedies that contain decongestants, including pseudoephedrine, phenylephrine, naphazoline, and oxymetazoline.