Some knowledges of the statin lipid-lowering drugs.📓📓📓

Statins are 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors. It not only potently lowers total cholesterol and low-density lipoprotein cholesterol (LDL-C), but also lowers triglyceride (TG) to a certain extent and raises high-density lipoprotein cholesterol (HDL-C). Therefore, statins are a more comprehensive lipid-lowering drug. The lipid-lowering efficacy and cardiovascular benefits of statins have been repeatedly confirmed and fully affirmed. Rational use of statins requires at least the following knowledges.

Cholesterol control targets for these individuals with statins:

Patients with coronary heart disease and stroke: LDL-C < 1.8mmol/L.

Patients with carotid artery stenosis greater than 50%: LDL-C < 1.8mmol/L.

Hypertensive patients with 2 to 3 risk factors: LDL-C < 2.6mmol/L.

Diabetic patients over age 40: LDL-C < 2.6mmol/L.

Risk factors include:

• Males ≥45 years old.
• Women ≥ 55 years old.
• Smoking.
• HDL-C < 1.0mmol/L.

Diabetic patients are more prone to cerebral infarction. Therefore, most people with diabetes need to take statins. HDL-C is commonly known as good cholesterol. It promotes the transfer of LDL-C (bad cholesterol) from peripheral blood vessels to the liver for elimination.

What do statins do?

Ability to regulate blood lipids:

• Atorvastatin can reduce LDL-C by about 39-50% and TG by about 19-29%. It increases HDL-C by about 6-9%.
• Pitavastatin can reduce LDL-C by about 34-47% and TG by about 23%. It increases HDL-C by about 12%.
• Rosuvastatin can reduce LDL-C by about 45-55% and TG by about 10-35%. It increases HDL-C by about 8-13%.
• Simvastatin can reduce LDL-C by about 23-35% and TG by about 21-39%. It increases HDL-C by about 9-14%.

Stabilize and reverse plaques:

• High levels of LDL-C can lead to inflammatory reactions in blood vessels. Statins play an anti-inflammatory role by lowering the levels of LDL-C in patients. Statins stabilize plaques through their anti-inflammatory effects. When statins significantly lower LDL-C and raise HDL-C, they will reverse atherosclerotic plaque.

Do statins need to be taken long-term? Can statins be discontinued when cholesterol reaches the target level?

Statins are required for taken long-term. As long as the patients have no contraindications and can tolerate statins, patients with cardiovascular and cerebrovascular diseases should insist on taking them. Studies have found that the longer the lipid-lowering treatment in patients with cardiovascular and cerebrovascular disease, the greater the reduction in the risk of cardiovascular and cerebrovascular events. 

Are all statins taken at bedtime?

The liver synthesizes cholesterol throughout the day, but the peaks of cholesterol synthesis are between 0:00 and 3:00. Therefore, some statins are recommended to be taken at bedtime. But their taking time also needs to consider their half-life and whether they will be affected by food.

1. Atorvastatin and rosuvastatin: They have longer half-lives and inhibit cholesterol synthesis throughout the day. Therefore, it has a great lipid-lowering effect and can be taken at any time.
2. Fluvastatin, pravastatin and simvastatin: They are rapidly absorbed orally and have a short half-life. They mainly inhibit the synthesis of cholesterol between 0:00 and 3:00. Therefore, they have little lipid-lowering effect and need to be taken before going to bed.
3. Pitavastatin: It has a longer half-life and is affected by enterohepatic circulation. It is generally required to be taken after dinner.
4. Lovastatin: Absorption is reduced by 30% when it is taken on an empty stomach. Food promotes its absorption, so it should be taken within 0.5 hours after dinner.

What are the precautions for statins?

Myalgia: If you have unexplained myalgia, seek treatment immediately. The incidence of statin-induced myopathy is approximately 1.5 to 5%. The symptoms of myalgia are easily ignored by patients. The main features of statin-induced myalgia are symmetrical hip flexor and thigh pain, symmetrical calf pain, and symmetrical upper extremity proximal muscle pain.

Liver discomfort: If you have liver discomfort, seek treatment immediately. Statins are hepatotoxic. In about 1 to 2% of all patients receiving statin therapy, liver enzyme levels increase above 3 times the upper limit of normal. Liver enzyme levels can drop after stopping the drug.

The interactions of statins with drug and food: 

1. Grapefruit: Try to avoid grapefruit while taking atorvastatin, lovastatin and simvastatin. This can increase the risk of myopathy.
2. Vitamin E: Studies have found that vitamin E significantly accelerates the clearance of simvastatin and reduces its lipid-lowering effect.
3. Erythromycin and clarithromycin: Atorvastatin, lovastatin and simvastatin should be avoided in combination with erythromycin and clarithromycin.
4. Amlodipine and ticagrelor: If used in combination with amlodipine, the dose of lovastatin and simvastatin should not exceed 20 mg/day. If used in combination with ticagrelor, the dose of lovastatin and simvastatin should not exceed 40 mg/day.