When taking atorvastatin, in addition to adverse reactions, you should also pay attention to interactions with other drugs

A friend left a message to Huazi, asking if there are any adverse effects when taking atorvastatin for a long time, and if there are any precautions. Huazi said that atorvastatin is a strong statin that can reduce low-density lipoprotein cholesterol (LDL-C) by up to 55%, but the adverse reactions are relatively low, so most people use atorvastatin when receiving statin treatment.

What needs to be noted during medication is that in addition to the adverse reactions of the drug itself, there are many interactions between atorvastatin and other drugs, so attention should be paid to the mutual effects of multiple drugs in combination.

1. Atorvastatin is a powerful statin that can be used in large doses. Among statins, those that can reduce LDL-C levels by less than 50% are medium-acting statins, and those that can reduce LDL-C levels by more than 50% are powerful statins. There are two powerful statins, atorvastatin and rosuvastatin, which can reduce LDL-C levels by 55% and 63% respectively.

However, to achieve the maximum lipid-lowering effect, a large dose is required. The maximum dose of atorvastatin is 80 mg per day, which is the same as the maximum dose used in China and abroad. The maximum dose of rosuvastatin abroad is 40 mg per day. Because Chinese people have poor tolerance, the maximum dose of rosuvastatin in China is only approved to be 20 mg per day, and 40 mg cannot be used.

Second, atorvastatin usually does not require high doses. The metabolites of atorvastatin are still active, and the overall half-life of the drug effect is more than 20 hours, so it is sufficient to take the drug once a day. The dosage is not affected by diet, and the LDL-C level is reduced by the same degree at any time of the day.

The initial dose of atorvastatin is 10 mg per day, and the dose is increased to 20 mg, 40 mg, and 80 mg per day. However, doubling the dose of statins only reduces LDL-C levels by 6%, while adverse drug reactions increase significantly. Chinese people are not tolerant to statins, so the 80 mg dose is generally not recommended.

3. Adverse reactions of atorvastatin Atorvastatin is a fat-soluble statin that mainly works by passive diffusion into liver cells. However, it is highly fat-soluble and can more easily pass through the blood-brain barrier into the central nervous system, so it may cause drowsiness and dreaminess; it may also cause nausea, abdominal discomfort and other digestive tract reactions in the early stage of taking the drug, but these adverse reactions will be alleviated or disappear in most patients with continued medication.

It should be noted that the effect of atorvastatin on liver function may cause an increase in liver transaminases (ALT, AST) during medication. If the transaminase exceeds 3 times the normal upper limit, the drug needs to be discontinued.

Taking atorvastatin may cause muscle damage, which manifests as muscle soreness and fatigue. When related symptoms appear, the creatine kinase (CK) level needs to be checked. If the CK value exceeds 5 times the normal upper limit, the drug needs to be stopped to avoid inducing the rare rhabdomyolysis.

Atorvastatin may cause an increase in blood sugar levels or new-onset diabetes. Diabetic patients need to adjust their glucose-lowering medications according to their blood sugar levels.

IV. Interactions between atorvastatin and drugs After absorption, atorvastatin is mainly metabolized by the hepatic enzyme CYP3A4 and has no effect on renal function. When used by patients with renal insufficiency, there is no need to adjust the dose. However, the hepatic enzyme CYP3A4 is a common metabolizing enzyme for many drugs, so atorvastatin interacts with many drugs.

Grapefruit (citrus fruit) has an inhibitory effect on the CYP3A4 enzyme, so while taking atorvastatin, you should avoid eating large amounts of grapefruit or drinking large amounts of grapefruit juice.

Drugs metabolized by CYP3A4 will compete with atorvastatin for enzyme binding, resulting in slower metabolism of atorvastatin and cumulative poisoning, so caution should be exercised when used in combination with such drugs.

Common drugs that may increase atorvastatin blood concentrations:

Macrolide antibiotics, such as erythromycin, clarithromycin, azithromycin, etc.

Conazole antifungal drugs, such as itraconazole, fluconazole, etc.

P-glycoprotein inhibitors, such as cyclosporine.

When used in combination with triglyceride-lowering drugs, gemfibrozil increases the risk of atorvastatin-induced muscle damage, so fenofibrate is usually used in combination, but attention should be paid to the symptoms of muscle damage when using the drug.

To sum up, atorvastatin is a commonly used powerful statin. It has fewer adverse reactions when used alone. Pay attention to the effects on transaminases and symptoms of muscle damage. It is metabolized by the liver and has no effect on the kidneys. It can be used by people with renal insufficiency. However, it has many interactions with other drugs. If multiple drugs are needed, pay attention to whether there are any mutual effects. Drugs should be used under the guidance of a doctor. If you have any questions about the use of medication, please consult a doctor or pharmacist in time. I am pharmacist Huazi, welcome to follow me and share more health knowledge.