Gemfibrozil side effects and precautions of gemcitabine

What are the common Gemfibrozil side effects?

Gemfibrozil side effects and precautions of gemcitabine
Gemfibrozil side effects and precautions of gemcitabine

Gemfibrozil side effects 1:

The most common adverse reactions include gastrointestinal discomfort, such as indigestion, anorexia, nausea, vomiting, bloating, and stomach discomfort. Less common adverse reactions include headache, dizziness, fatigue, rash, itching, and erectile dysfunction.

Gemfibrozil side effects 2:

Gemfibrozil side effectsThere are occasional cases of cholelithiasis or myositis (muscle pain, fatigue). As a derivative of clofibric acid, gemfibrozil may cause myositis, myopathy, and rhabdomyolysis, leading to an increase in creatine phosphokinase. The main manifestations of rhabdomyolysis include muscle pain accompanied by an increase in creatine phosphokinase, myoglobinuria, and it may lead to renal failure, though this is rare. The risk of myopathy increases in patients with nephrotic syndrome and other renal impairments leading to hypoalbuminemia or in those with hyperthyroidism.

Gemfibrozil side effects 3:

There are occasional abnormalities in liver function tests (elevations in amino transferase, lactate dehydrogenase, bilirubin, alkaline phosphatase) that typically return to normal upon discontinuation of the medication.

Gemfibrozil side effects 4:

There are occasional cases of mild anemia and leukopenia, but long-term use may stabilize these conditions. In rare cases, severe anemia, leukopenia, thrombocytopenia, and bone marrow suppression have been reported.

Can special populations take this medication?

1.Use in pregnant and breastfeeding women:

High doses of this medication in animals have been shown to cause fetal death, and there are no reports on human studies. It is unknown whether this medication passes into breast milk, therefore it is not recommended for use by pregnant or breastfeeding women.

2.Use in children:

The study of this medication in children is not sufficient, and its use should be considered carefully weighing the benefits and risks.

3.Use in the elderly:

In elderly patients with renal impairment, the dosage of this medication should be appropriately reduced.

Development background of gemfibrozil:

Gemfibrozil is a clofibric acid derivative class of lipid-regulating medication, chemically known as 2,2-dimethyl-5-(2,5-dimethylphenoxy)pentanoic acid. It was first developed by Pfizer Inc. in the 1970s and was marketed in the United States in 1981 under the brand name Lopid. Gemfibrozil is an agonist of both peroxisome proliferator-activated receptor α (PPARα) and PPARγ, capable of lowering triglycerides and low-density lipoprotein cholesterol in the blood while increasing high-density lipoprotein cholesterol.

The mechanism of its lipid-lowering effect is not fully understood but may involve the breakdown of peripheral fat, reducing the liver’s uptake of free fatty acids and thus decreasing the formation of triglycerides in the liver, and inhibiting the synthesis of very low-density lipoprotein carrier proteins, thereby reducing the production of very low-density lipoproteins.

Advantages of Gemfibrozil:

Gemfibrozil is a non-halogenated clofibric acid derivative lipid-lowering medication that effectively reduces levels of total cholesterol, total triglycerides, very-low-density lipoprotein cholesterol and triglycerides, low-density lipoprotein cholesterol, and triglycerides, while increasing the concentration of high-density lipoprotein cholesterol. Gemfibrozil overcomes the serious hepatic side effects of the previously used lipid-lowering drug, clofibrate, while retaining its effective action. It helps in reducing the incidence of myocardial infarction and can be used long-term. Due to its safety and reliability, it has been included in the United States Pharmacopeia, becoming a statutory medication.

Animal and clinical trials have shown that its lipid-lowering effect is superior to that of similar agents. Currently, there are few drugs available clinically that can effectively lower TC, TG, LDL-C, and increase HDL-C, and some of them still have certain side effects. Years of clinical use have shown that gemfibrozil has a significant therapeutic effect with minimal side effects, providing a better medication option for patients with hyperlipidemia.

Drug Interactions:

When used concurrently with other drugs that have a high protein-binding rate, gemfibrozil can displace them from their protein-binding sites, enhancing their effects. This interaction is observed with drugs such as tolbutamide and other sulfonylurea hypoglycemic agents, phenytoin, and furosemide. Gemfibrozil can significantly enhance the effect of oral anticoagulants. When used together, it is necessary to reduce the dose of the oral anticoagulant and regularly monitor prothrombin time to adjust the anticoagulant dose.

The combination of clofibric acid derivatives and HMG-CoA reductase inhibitors, such as lovastatin, increases the risk of severe myotoxicity, which can lead to myalgia, rhabdomyolysis, and elevated creatine phosphokinase levels. This combination should be avoided if possible. When used with bile acid-binding resins, such as colesevelam, gemfibrozil should be taken at least 2 hours before or after these medications. When used with immunosuppressants, such as cyclosporine, it can increase the blood concentration and renal toxicity of the latter, posing a risk of worsening renal function, and dosage reduction or discontinuation may be necessary.

Case Study on Drug Interactions:

A 57-year-old female patient was admitted to the hospital for type 2 diabetes with peripheral neuropathy and abnormal blood lipids. She was prescribed gemfibrozil capsules 0.6g, three times a day orally; repaglinide tablets 1mg, three times a day orally; and insulin glargine injection 10U/day, subcutaneously. Her blood sugar levels fluctuated. After replacing repaglinide with acarbose tablets (50mg, three times a day, orally) for two weeks, the patient’s blood sugar and lipid levels were well controlled.

Case Analysis:

Repaglinide is metabolized primarily by the liver cytochrome P (CYP) 450 enzyme system, mainly CYP3A4 and CYP2C8. Gemfibrozil is a CYP2C8 inhibitor, and when taken with repaglinide, can significantly increase the plasma drug concentration of repaglinide, enhancing its hypoglycemic effect and prolonging its action, potentially leading to hypoglycemia. Repaglinide and gemfibrozil have similar drug interactions. Miglitol is metabolized directly by phase II metabolism enzymes (uridine diphosphate glucuronosyltransferase) and only a small amount by CYP2C9. Compared to repaglinide, the risk of hypoglycemia when miglitol is combined with gemfibrozil is lower.


  1. Repaglinide and gemfibrozil should not be used together; miglitol can be used to replace repaglinide.
  2. If repaglinide and gemfibrozil must be used together, the patient’s blood sugar levels should be closely monitored, and the dose of repaglinide adjusted according to blood sugar levels.

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