What You Need to Know About PCSK9 Inhibitors

Medically Reviewed by James Beckerman, MD, FACC on June 04, 2022
4 min read

If you need medicine to lower your cholesterol, chances are your doctor will prescribe a statin. But these drugs aren’t always enough. And some people can’t take them because of their side effects. That’s why experts are calling new drugs known as PCSK9 inhibitors a game-changer.

PCSK9 inhibitors are a new class of drugs that lower LDL, or “bad,” cholesterol. Right now, there are two FDA-approved medications: alirocumab (Praluent) and evolocumab (Repatha).

Studies show that PCSK9 inhibitors have a powerful effect and in some cases can actually prevent heart attacks or strokes. They can be taken on their own or in addition to a statin. But they’re also much more expensive than other cholesterol drugs.

PCSK9 inhibitors are proteins made in a laboratory. They target other proteins in your body, specifically your liver.

Your liver cells have receptors that sweep away excess cholesterol. But another protein called PCSK9 destroys them. That’s where inhibitors come in. They latch onto PCSK9 proteins and block them from acting. The result: More receptors are able to do their job. This lowers the amount of LDL cholesterol in your blood.

In fact, one review of studies found that PCSK9 inhibitors slash LDL levels by an average of 47%. This protects your heart: The drugs were shown to reduce the risk of heart attack by 27%.

Statins work in a different way. One main way they work is to block an enzyme that your liver needs to make cholesterol. This lowers your LDL level. Statins are taken as pills, while PCSK9 inhibitors come only as shots.

PCSK9 inhibitors can be used with statins to boost their benefit. The combination can lower LDL levels by more than half.

Statins are the most common drug that lowers cholesterol. Doctors usually prescribe them first because they get the job done and most people can afford them.

But they don’t work for everyone. You may want to ask your doctor about PCSK9 inhibitors if:

  • You have genetic high cholesterol: About 600 thousand Americans have a genetic disorder called familial hypercholesterolemia. It affects how your body processes cholesterol. For most people with this condition, even the highest dose of statins won’t bring their LDL cholesterol down to a healthy level.
  • You’re at risk for heart attack or stroke: If you already have heart disease and other medications, like statins, aren’t working, your doctor may consider PCSK9 inhibitors.
  • You can’t take statins: About 10% to 20% of people who do have side effects, like muscle pain, cramps, or weakness. They can also cause liver damage, confusion, memory loss, or a rise in blood sugar.

Most people with high cholesterol don’t need PCSK9 inhibitors. The FDA has only approved alirocumab and evolocumab for people with genetic high cholesterol or serious heart disease including those who’ve already had a heart attack or stroke and who need their LDL cholesterol lower. If you don’t have either of these conditions, your doctor will likely recommend another treatment.

They’ll try different treatments before they give you PCSK9 inhibitors. The first is usually lifestyle changes. They’ll tell you to eat right and get more exercise. Both will help lower your cholesterol. You’ll likely need to see a dietitian for tips on how to improve your diet.

You may also need to take a statin. If your cholesterol doesn’t go down, your doctor will prescribe higher doses. If the maximum amount still doesn’t work -- or if you can’t handle the side effects -- your doctor may consider a PCSK9 inhibitor. They also may order tests, like a coronary calcium score, to check your heart disease risk. If you are diagnosed with heart disease, they may opt for prescribing evolocumab because of its effectiveness in preventing heart attacks and strokes.

You might take the PCSK9 inhibitor alone or paired with other cholesterol-lowering medications, like statins.

PCSK9 inhibitors are given as a shot every 2 or 4 weeks. You’ll need to inject the medicine in your upper arm, stomach, or upper thigh. The doctor will teach you how to do it properly. The injection is usually easy with little pain. And you won’t have to remember to take a pill every day.

The most common side effects are mild. They include back pain and symptoms of a cold or the flu. Because it’s an injection, you may also have redness, bruising, or pain around the area where you administer the shot. These drugs may also cause an allergic reaction in certain people. If you develop a severe rash, swollen face, or trouble breathing, get emergency help right away.

These drugs aren’t cheap. The price tag rings in at more than $14,000 per year. How much you’ll pay out of pocket depends on your health insurance. You may be able to apply for a patient assistance program to offset the cost. Ask your doctor about your options.