PCSK9 inhibitors are a type of medication that lowers cholesterol. Doctors may prescribe them to people alongside statins and other cholesterol-lowering drugs.

High cholesterol is a health issue that increases the risk of heart disease and other chronic conditions. High cholesterol generally refers to a higher proportion of low-density lipoprotein (LDL) cholesterol rather than other types of cholesterol.

Doctors commonly prescribe statins to help manage cholesterol levels. However, they are not effective or tolerable for everyone. Doctors may also prescribe PCSK9 inhibitors as a complementary or alternative approach for lowering cholesterol.

In this article, we will explore PCSK9 inhibitors, their effects on cholesterol, and who should take them.

Medication and a glass of water-2.Share on Pinterest
Yulia Reznikov/Getty Images

Proprotein convertase subtilisin/kexin type 9, or PCSK9 inhibitors, are a class of medications that lower LDL cholesterol in the blood. Typically, these medications are a type of monoclonal antibody. This refers to a type of artificial protein that can bind to certain targets within the body.

PCSK9 inhibitors are monoclonal antibodies, which are a type of drug that mimic the effects of an antigen. Antigens are a natural part of the immune system that act on specific proteins.

In the case of PCSK9 inhibitors, they specifically target and inhibit the PCSK9 protein. As this protein binds to LDL receptors, it can make it more difficult for the body to remove cholesterol. Evidence notes that people with higher levels of PCSK9 tend to have higher cholesterol levels. As such, by inhibiting this protein, the body is better able to reduce LDL cholesterol levels.

Currently, there are two main PCSK9 inhibitors: evolocumab and alirocumab.

Evolocumab is a type of PCSK9 inhibitor available as an injection that reduces LDL cholesterol. It comes under the brand name Repatha. Alirocumab, also known under the brand name Praluent, also comes as an injection and acts on the PCSK9 protein to reduce LDL cholesterol.

People typically take these medications as an injection under the skin. A doctor may administer them, or individuals can learn to self-administer the injections. A person will typically administer these medications via a subcutaneous injection.

PCSK9 inhibitors can help effectively reduce LDL cholesterol levels in the bloodstream. Evidence states that these drugs reduce LDL cholesterol by up to 70%.

Additionally, PCSK9 inhibitors can also reduce other types of cholesterol that can harm health in high amounts, such as lipoprotein (a), by 30–40%. They can also help increase “healthy” high-density lipoprotein cholesterol by 8–10%.

PCSK9 inhibitors may also improve the outcomes of people with chronic diseases, such as heart disease. For example, a 2018 study of almost 19,000 individuals with coronary syndrome found that taking alirocumab reduced the risk of heart attacks compared with a placebo.

A 2016 study of almost 1,000 people with coronary disease also found that evolocumab reduced LDL cholesterol levels compared with a placebo. This study included people who were already taking statins for their LDL cholesterol.

PCSK9 inhibitors are safe but can lead to side effects. Common side effects may include:

  • pain or swelling at the injection site
  • cold- or flu-like symptoms
  • respiratory infections
  • stomach pain
  • muscle aches and pain
  • tiredness
  • difficulty thinking
  • headaches
  • rashes

Statins have been a standard treatment for high cholesterol for many years. They block a liver enzyme that produces cholesterol. This reduces the amount of LDL cholesterol in the bloodstream.

Statins help reduce the buildup of plaque to reduce the risk of heart attacks and strokes. They are a typically safe form of medication with various long-term health benefits and a low risk of serious side effects.

Doctors may prescribe PCSK9 inhibitors in addition to statins for people who cannot reach their target LDL cholesterol levels with the former drug alone. They might also prescribe PCSK9 inhibitors as an alternative to statins for those who experience major side effects.

For example, a 2016 trial found that adding PCSK9 inhibitors to the treatment of people taking statins reduced their LDL cholesterol levels effectively.

PCSK9 inhibitors are highly effective, but they are also more expensive than statins. People may need to consider these costs with their doctors and health insurers when deciding to include them in their treatment.

Anyone with high LDL cholesterol could potentially benefit from taking PCSK9 inhibitors. People with heart disease or diabetes may also benefit from taking PCSK9 inhibitors to reduce their risk of developing high cholesterol.

These medications may be particularly useful for people who cannot sufficiently reduce their LDL cholesterol with statins alone. Additionally, some individuals who experience major side effects from statins may benefit from PCSK9 inhibitors as an alternative treatment.

PCSK9 inhibitors are a class of medication that helps lower LDL cholesterol in the bloodstream. These medications block the action of PCSK9. The PCSK9 proteins bind to LDL cholesterol receptors and make it more difficult for the body to lower cholesterol levels.

PCSK9 medications can reduce the risk of people having heart attacks and other health problems. They are generally safe but can cause some side effects, such as soreness at the injection site. They are also expensive. People who cannot sufficiently reduce their LDL cholesterol levels or experience major side effects from statins may benefit from PCSK9 inhibitors. Doctors may prescribe them in addition to or in place of statins.