What Are The Top 4 Most Effective Drugs For Diastolic Hypertension?

Hypertension — or high blood pressure — is known as the silent killer, one that leads to the deaths of almost half million people in the US every year, many of whom never notice any specific symptoms. However, not all types of hypertension are the same, nor do they carry the same risk of atherosclerosis and stroke.

What do you need to know about diastolic hypertension? What medications are best used to treat it? This guide will help you get some answers, whether you have recently been diagnosed or are simply curious.

What is diastolic hypertension?

Your heart is a muscular pump that works in cycles, each consisting of two phases.

The lower chambers of your heart squeeze and push blood into the arteries and the rest of your body. This part is called systole, and the force that your blood exerts on the artery walls during this period is called systolic blood pressure. This is the upper value you see when measuring your blood pressure at home.

Diastole is also the phase when coronary blood vessels (the vessels that supply the heart muscle) deliver blood to the heart muscle. High or low values of blood pressure are usually a sign of changes in your cardiovascular system that could cause problems in the future.

Hypertension can be combined, when both values are elevated, or it can be isolated — when only systolic or diastolic blood pressure is elevated. In 2017, the American Heart Association (AHA) issued new guidelines for hypertension, defining elevated blood pressure as anything above 130/80 mm Hg.

The new criteria defined isolated diastolic hypertension as systolic blood pressure less than 130 mm Hg with a diastolic blood pressure higher or equal to 80 mm Hg. 

Is diastolic hypertension dangerous?

Diastolic hypertension was initially thought to be the most important predicament of cardiovascular disease, more so than systolic. However, studies done in the last decade have proven the opposite. While systolic hypertension was always associated with a higher risk of heart attack and stroke, this wasn’t true for patients with elevated diastolic pressure whose systolic blood pressure was under 140 mm Hg. 

The truth is that we are still unsure of the exact way in which diastolic hypertension affects the heart. The medical community is divided on this subject, with one part believing that diastolic hypertension is a risk factor for heart attack and stroke, and the other claiming otherwise. Studies done in the last few years support the idea that diastolic hypertension doesn’t carry a direct risk of cardiovascular events.

Elevated diastolic blood pressure usually happens in people younger than 45, while systolic hypertension is more common in older adults. By managing diastolic hypertension, you could avoid developing systolic hypertension in your older years, and thereby also all the risk it carries. This is why it is important not to ignore diastolic hypertension.

Do you need treatment for diastolic hypertension?

Whether to treat hypertension when only the diastolic blood pressure is elevated remains a debate in the medical community. Usually, diastolic hypertension will be treated and closely monitored if you have other chronic diseases like diabetes or chronic kidney disease, or a history of heart attack. Risk factors like atherosclerosis and smoking also point to the direction of drug therapy.

For some people, lifestyle changes can be enough to bring their diastolic blood pressure back to normal.

Pharmaceutical therapy for hypertension does come with some risk. Antihypertensive drugs are usually very effective in lowering diastolic blood pressure, and sometimes even too effective. A diastolic blood pressure under 60 mmHg — hypotension, when your blood pressure drops too low — leads to heart damage and it’s directly associated with many unfavorable outcomes, including death from both cardiovascular and non-cardiovascular causes.

Several studies have shown that, for people with a history of heart diseases, even values lower than 75 can be dangerous and were associated with higher mortality. However, with some patience you and your physician could find a medication and a dose that lowers your blood pressure to the ideal value, rather than beyond it.

Which drugs are most effective for diastolic hypertension, and how do they work?

You can’t target diastolic blood pressure alone, so the same type of drugs are used in treating both diastolic and systolic or combined hypertension. In fact, the antihypertensive drugs that are currently used are more effective in lowering diastolic than systolic blood pressure.

Most patients with diastolic hypertension need only one or sometimes two types of medications, while systolic hypertension often requires a combination of different medications. 

1. Calcium channel blockers (Calcium antagonists)

Both the American Heart Association and European Society of Cardiology recommend calcium antagonists as the first line of treatment.

The contraction of muscle cells is regulated by movement of calcium ions in and out of the cell through channels on the membrane. There are different types of calcium channels, depending on the type of muscle cell.

This class of medication targets calcium channels on the cells that build the walls of your arteries as well as heart muscle cells, and prevent calcium from entering.

The arteries relax and widen, causing the blood pressure to drop. The force of heart contractions is also lowered. Additionally, these medications act on cells that make the hormone aldosterone and reduce its production, which also leads to lowered blood pressure.

Some commonly used calcium channel blockers include:

• amlodipine (Norvasc)
• diltiazem (Cardizem, Tiazac)
• felodipine

While calcium channel blockers were shown to be more effective in reducing the risk of death than some other blood pressure medications, they also have more side effects. Almost 70 percent of patients experience swelling in their legs or arms, and constipation is also frequent. Some calcium antagonists can be toxic.

2. Diuretics

Diuretics or water pills help you to get rid of excess water and salt. That way there’s less fluid in your body, which also means diuretics lower blood pressure effectively. In the US, thiazide-type diuretics, like chlorthalidone (Thalitone), hydrochlorothiazide (Microzide), and methyclothiazide are recommended as the first line of treatment for hypertension, since they’re generally considered both safe and effective.

3. ACE inhibitors (Angiotensin-converting enzyme inhibitors)

ACE inhibitors considered very effective in the treatment of high blood pressure and they are often the first line of treatment, but not for all racial groups, since these medications can cause complications for African-American hypertensive patients.

Blood pressure is tightly regulated in your body through several mechanisms. One of them is the renin-angiotensin system. When blood flow to the kidneys is reduced, a substance called renin is released into the bloodstream. This is a signal for a hormone called angiotensin I to be made.

We don’t really know what role of angiotensin I plays, but it can be converted to angiotensin II which has several effects on the body, all of which lead to increased blood pressure. It narrows the blood vessels and causes water retention while increasing thirst. The role of this class of drugs is to disable the enzyme and prevent it from making angiotensin II.

Drugs from this class include:

• captopril (Capoten)
• enalapril (Vasotec)
• fosinopril (Monopril)
• lisinopril (Prinivil, Zestril)
• perindopril (Aceon)
• quinapril (Accupril).

While you’re taking ACE inhibitors, it’s important to watch your potassium intake. Many people reach for salt-substitutes rich in potassium, but this class of drugs already makes you retain more potassium and adding extra can lead to hyperkalemia (too much potassium) which can be life-threatening. 

4. Angiotensin II receptor blockers (ARBs)

For people who are extra sensitive to ACE inhibitors, ARBs can be a better choice. ARBs act on the same system, but through a different mechanism. Angiotensin II is made, but it can’t bind to the receptors on the cells. This is because the drug has already taken the spot of angiotensin II, and it can’t exhibit any effects.

Commonly used ARBs are:

• irbesartan (Avapro)
• losartan (Cozaar)
• olmesartan (Benicar)
• telmisartan (Micardis)
• valsartan (Diovan)

Even though ARBs effectively lower blood pressure, there were concerns that they might raise the risk of heart attack. In 2006, the American Heart Association re-examined this class and there is currently no agreement on whether they can increase your odds of a heart attack.

All classes of high blood pressure medications have the potential to cause side effects, and if your physician is advising you to start taking hypertension medications, it is important to discuss the pros and cons of each. Should you notice unusual symptoms after you begin using these medications, don't forget to inform your doctor about them, either — so that they can try switching you to a different drug if necessary.