Medications and Hypertrophic Cardiomyopathy: What To Avoid, What To Discuss

If you’ve recently been diagnosed with hypertrophic cardiomyopathy (HCM), you may have come across a long list of medications that you shouldn’t take. But that’s not the whole story.

“Certain medicines may not be optimal to take with hypertrophic cardiomyopathy,” says cardiologist Maran Thamilarasan, MD. “That’s not to say they can’t be used. It’s just that you and your physicians should be aware that there could be some interaction.”

In other words: Don’t stop taking your medications. Do start a conversation.

Prescription medications

Whether the medications you currently take are safe depends on both the type of HCM you have and your health history.

At its core, HCM is a blood flow problem. It happens because the wall of your heart’s left ventricle is abnormally thick. Your diagnosis explains why.

• In obstructive HCM, the thickened heart muscle narrows the space inside the ventricle, blocking or obstructing blood flow.
• In non-obstructive HCM, the wall of your left ventricle has grown larger and stiffer. There’s no obstruction to blood flow

That difference affects the kinds of medications you can take — and what a safe dose looks like.

“In obstructive HCM, there are certain drugs that can make the blockage worse,” Dr. Thamilarasan says.

While the guidance around non-obstructive HCM isn’t as strict, it’s still vital to clear all of your medications with your cardiologist. Whatever your diagnosis, they’ll weigh the risks and benefits of all the medications you’re taking and their dosages.

Your cardiologist may:

• Suggest alternative medications
• Adjust the dose
• Stop the medication completely

Here are a few types of drugs that are always worth a conversation.

Vasodilators

Vasodilators are usually prescribed for high blood pressure because they help your blood vessels relax and expand (vasodilation), which improves blood flow. But if you have obstructive HCM, the combo of increased blood flow and decreased arterial pressure could put added stress on your heart.

“When you experience vasodilation, your heart may beat more vigorously in response,” explains Dr. Thamilarasan. “That can make the obstruction worse.”

That doesn’t mean these drugs are always off-limits if you have both obstructive HCM and high blood pressure. It just means that your cardiologist will need to weigh your treatment options carefully.

ACE inhibitors and ARBs

ACE inhibitors and angiotensin II receptor blockers (ARBs) are common blood pressure medications that usually aren’t a first-choice treatment for people who have both high blood pressure and obstructive HCM.

If the ACE inhibitor or ARB you’re taking for your blood pressure treatment isn’t working well, your cardiologist may want you to stay on them. But Dr. Thamilarasan says that they’ll need to monitor you carefully to be sure the obstruction in your left ventricle doesn’t get worse.

Nitrates

If you have angina, you may be on nitrates like nitroglycerin — and if you’ve been diagnosed with obstructive HCM, that treatment may need to be adjusted.

Angina happens when the narrowing of your coronary arteries limits blood flow to your heart, creating an oxygen deficit. Nitrates widen your blood vessels (both veins and, to a lesser extent, arteries), which improves blood flow and relieves that discomfort.

But if you have obstructive HCM, nitrates can decrease the volume of blood filling your ventricles before your heart contracts. Cardiologists call this “preload.”

“If you have obstructive HCM, dropping that preload can cause the obstruction to get worse,” Dr. Thamilarasan explains. “But if you have both coronary artery disease and HCM, you may still need to be on nitrates. You’ll need to work with your cardiologist to determine the best path forward.”

Another thing to keep in mind: If you have both HCM and coronary artery disease, it may not be clear what’s causing your chest pain. Your provider will need to closely monitor your blood flow to figure out the likely culprit.

Calcium channel blockers

Sometimes, different types of drugs within the same class interact differently with HCM. Calcium channel blockers are a good example.

Calcium channel blockers are a common treatment for several different heart conditions, including arrhythmia and coronary artery spasms. They’re also used off-label to treat other conditions, from migraines and Raynaud’s phenomenon to anal fissures.

• Dihydropyridine calcium channel blockers (like amlodipine and nifedipine) act like vasodilators, so cardiologists tend not to prescribe them if you have obstructive HCM.
• Non-dihydropyridine calcium channel blockers (like verapamil and diltiazem) are a good alternative. They cause less vasodilation.

OTC drugs and supplements

If you have an HCM diagnosis, it’s crucial that you tell your cardiologist about everything you take, including over-the-counter (OTC) treatments and supplements. In addition to worsening your HCM symptoms, these substances could interact with your other medications.

Decongestants

Taking certain OTC cold and allergy medicines can be dangerous if you’re living with HCM. The ingredients can raise both your heart rate and blood pressure, upsetting the delicate balance of blood flow needed to keep HCM symptoms in check.

Dr. Thamilarasan recommends that you:

• Use OTC medications that don’t contain decongestants, like plain antihistamines. Also look for medications that don’t have a “D” at the end, like loratadine instead of loratadine-D or cetirizine instead of cetirizine-D.
• Try an over-the-counter saline nasal spray.
• Rinse your sinuses with a neti pot.

NSAIDs

“Nonsteroidal anti-inflammatory drugs (NSAIDs), like ibuprofen and naproxen, can cause fluid to build up in your body if you have HCM,” Dr. Thamilarasan warns. “If you already have heart failure symptoms, that extra fluid can be a problem.”

All pain is different, so talk to your provider about how best to manage yours. For many people, taking acetaminophen (within safe dosing limits) or using a topical NSAID gel are good alternatives, but you’ll still want to clear those options with your cardiologist.

If those OTC solutions don’t put a dent in your pain, tell your provider.

Diuretics

If you have obstructive HCM, it’s often not safe to take water pills for bloating. Dr. Thamilarasan explains that taking too much can lower your volume and worsen the obstruction in your left ventricle — but the only person who can tell you what “too much” means for you specifically is your cardiologist.

Some people need to be on prescription diuretics to deal with heart failure symptoms or other health issues. In that case, your cardiologist will monitor you closely for signs of complications.

Supplements

Herbal and dietary supplements — including caffeine pills, pre-workout powder and anything else that alters your energy levels — could affect your heart or interact with the drugs you take.

“Some supplements can cause blood vessels to dilate, lowering your blood pressure. Others can raise your heart rate and blood pressure or thin your blood,” Dr. Thamilarasan states. “Your cardiologist needs to be aware of that when they’re prescribing heart medications for you.”

Also, keep in mind that these products aren’t regulated by the U.S. Food and Drug Administration (FDA). Their ingredients, quality and effectiveness aren’t guaranteed, which adds another layer of risk and uncertainty your cardiologist needs to know about.

Vitamins

While vitamins may seem innocent enough, some can increase your risk of heart disease complications. Bring a list of everything you’re taking to your cardiology appointments to make sure you’re not taking anything that could make your HCM symptoms worse.

Be honest with your provider

While it can be uncomfortable to talk about, substance use can also affect your HCM treatment plan. Whether you’re in recovery or actively using substances, it’s crucial that you let your cardiologist know.

Cocaine, for example:

• Raises blood pressure
• Increases heart rate
• Increases the force of heart muscle contractions
• May reduce blood flow to your heart by narrowing blood vessels

All these different changes can add stress to your already-stressed cardiovascular system ... but there’s more. Many people with HCM are prescribed beta-blockers. And that combination’s a recipe for trouble.

“If we prescribe a beta-blocker and someone goes out the next day and uses cocaine, there’s the potential for a dangerous interaction,” Dr. Thamilarasan stresses.

That’s why you can’t hold anything back when it comes to HCM and substance use.

Start the conversation

If you have a new HCM diagnosis, you may be tempted to use lists like this one as a source of truth. Instead, use them to write a list of your own — a list of questions for your doctor, that is.

“The idea is to raise the discussion with your cardiologist,” Dr. Thamilarasan advises. “Don’t read this and stop the drugs you’re currently on.”

Check with your care team before making any changes. They’ll use what they know about your specific heart condition to craft a safe and effective HCM treatment plan.