Drug example: Evolocumab and alirocumab
Mechanism of action: Drugs in this class are antibodies that bind to PCSK9 in the plasma. PCSK9, an enzyme produced mainly by the liver, normally binds to receptors in the liver and causes higher LDL levels. These antibodies bind up free PCSK9 in the plasma, making the enzyme unavailable to bind to the receptors on the liver cells. This leads to lower levels of LDL. It is also believed that these drugs have an anti-inflammatory effect on the blood vessel wall, resulting in less atherosclerosis.
Use: These drugs are different from other lipid-lowering medications in that they are given via subcutaneous injections. They can lower LDL by up to 65% in some individuals. They also increase HDL and lower triglycerides. At this point in their early existence, PCSK9 inhibitors are used as an add-on medication to patients who are already taking the maximum amount of a “statin” medication that they can tolerate but still need an additional decrease in LDL.Drug toxicity:
These drugs do not cause muscle injury or elevated liver enzymes. They are relatively well tolerated by patients, with the most common reactions being skin reactions at the site of drug injection.