What are fibrates?

Fibrates, available on prescription, are oral derivatives of fibric acid, which are called hypolipidemic agents because they lower triglycerides. In addition, they increase HDL, the good cholesterol.

However, their action in lowering LDL is less effective. Fibrates may lower triglycerides by 25% to 50% and can increase HDL by 10% to 35%.

They also help to reduce insulin resistance in patients with dyslipidemia who have other signs of metabolic syndrome such as hypertension and diabetes type 2.

Mechanism of action 

Fibrates help by improving the insulin resistance and therefore, they become useful in cases of metabolic syndrome, which is one of the complications that may develop as a result of high triglyceride levels.( explained in high triglycerides causes and dangers).

Fibrates activate the PPAR-a receptors, which are present in muscles, liver and some other tissues. This activation facilitates lipid metabolism, which results in decreased secretion of triglycerides from the liver, an increased removal of VLDL due to increased lipoprotein lipase activity, and increase in HDL levels.

Types and brand names

There are several types of fibrates available on prescription such as:

  • Bezafibrate – brand name Bezalip
  • Ciprofibrate – brand name Modalim
  • Gemfibrozil – brand name Lopid
  • Fenofibrate – brand names Tricor, Fibricor

Uses of fibrates

Fibrates work wonderfully well and are indicated in most forms of hypercholesterolemia in conjunction with statins to lower cholesterol.

They are also used as a monotherapy (alone) but since they do not do not improve all-cause mortality such as due to heart problems, they are used more in individuals who cannot tolerate statins.

Side effects  

Side effects in the majority of the cases are mild and temporary. They include skin rash, nausea, and stomach upset.

Some more rare side effects include chest pain, muscle weakness, and gall stones. When used with statins, there may be muscle weakness and renal failure.

Caution when using fibrates

Fibrates should not be used in people who are having liver or kidney impairment and gall bladder disease. It is also contraindicated in pregnant mothers because of the adverse effects it can have on the fetus.

Rarely, a paradoxical decrease in HDL cholesteol is seen in some patients on fenofibrate. Therefore, it is recommended that the HDL cholesterol levels be checked within the first few months after starting the patient on fibrate therapy. If severely low levels of HDL-C are detected, fibrates should be withdrawn, and the HDL levels be monitored till they normalize.

Fibrates can enhance the effect of blood thiiners such as Warfarin when both are used together. Therefore, in such cases there is need to regulate the dose of fibrates to avoid over-thinning of the blood, which can lead to excessive bleeding.