Is a lipid-lowering injection taken once a month better than statins? Who needs it?

An elderly friend told Huazi that he had high blood lipids and experienced adverse reactions such as lower back and back muscle soreness after taking statins. However, he heard that there is a lipid-lowering injection that is given once a month that is very effective. Can he take that injection in the future instead of taking statins?

Huazi said that the lipid-lowering injection he was talking about is a "proprotein convertase subtilisin/kexin-9 inhibitor", abbreviated as PCSK9 inhibitor . Currently, there are two drugs on the market in China: evolocumab and alirocumab.

How do PCSK9 inhibitors work?

Low-density lipoprotein cholesterol (LDL-C) in blood lipids is the main cause of atherosclerosis. Reducing the level of LDL-C can reduce the risk of cardiovascular and cerebrovascular diseases . LDL-C is mainly produced by the liver, and the liver also has corresponding LDL receptors that can degrade LDL-C.

PCSK9 in the human body will bind to LDL receptors, resulting in a decrease in the number of LDL receptors, thereby reducing LDL-C degradation and increasing LDL-C levels in the blood.

PCSK9 inhibitors will bind to PCSK9 and inactivate it , thereby increasing the number of LDL receptors and increasing the degradation of LDL-C, which can reduce LDL-C levels by about 50%~70%.

2. Used to enhance treatment when statins are not effective

Statins alone can usually reduce LDL-C levels by 50%. Although PCSK9 inhibitors are more effective than statins in reducing LDL-C levels, they cannot completely replace the effects of statins .

Because statins can not only lower LDL-C levels, but also improve arterial intima metabolism, antioxidant and anti-inflammatory responses, increase the stability of atherosclerotic plaques, prevent rupture, and promote their reversal.

Therefore, statins are still the main drugs for controlling LDL-C levels . If statins alone cannot achieve standard blood lipids, they are usually used in combination with cholesterol absorption inhibitors (ezetimibe) first. When the combination of statins and ezetimibe cannot control LDL-C levels to standard, PCSK9 inhibitors are added.

Usually, PCSK9 inhibitors are not used alone, but only in combination with statins . However, if statins are completely intolerant, PCSK9 inhibitors can also be used alone.

Statins alone can reduce LDL-C levels by about 50%; statins plus ezetimibe can reduce LDL-C levels by about 65%; statins plus PCSK9 inhibitors can reduce LDL-C levels by about 75%; statins, ezetimibe and PCSK9 inhibitors can reduce LDL-C levels by about 85%.

3. Precautions for PCSK9 inhibitors

All PCSK9 inhibitors require subcutaneous injection, with evolocumab injected once a month and alirocumab injected once every 2 weeks .

Common adverse reactions of PCSK9 inhibitors are erythema, pain, and bruising at the injection site . In clinical trials, the incidence of upper respiratory tract infection, influenza, gastroenteritis, and nasopharyngitis increased after taking the drug.

The drug may cause allergies and should be discontinued if severe allergic reactions occur . The drug contains protein, which may stimulate the body's immune system to produce neutralizing antibodies, which will increase local reactions during injection, but will not affect its lipid-lowering effect.

The use of PCSK9 inhibitors will not increase the adverse reactions caused by statins, such as muscle damage, abnormal liver function, and increased blood sugar .

In summary, PCSK9 inhibitors are new lipid-lowering drugs, but they cannot replace statins. When statins cannot bring LDL-C to the target, they can be used in combination with PCSK9 inhibitors. Only those who cannot tolerate statins at all can use PCSK9 inhibitors alone for treatment.

Some people are prone to adverse reactions when using high-intensity statins. They can also switch to moderate-intensity statins plus PCSK9 inhibitors for treatment. The drug must be used under the guidance of a doctor. If you have any questions about the use of the drug, please consult a doctor or pharmacist. I am pharmacist Huazi. Welcome to follow me and share more health knowledge.