Your Cholesterol Profile - In Depth (cont.)
What are fibric acid derivatives (fibrates)?
Fibric acid derivatives (fibrates) are effective medications in lowering blood
triglyceride levels. Fibrates lower blood triglyceride levels by inhibiting the
liver production of VLDL (the triglyceride-rich lip-protein fraction), and by
speeding up the removal of triglycerides from the blood. Fibrates are also
modestly effective in increasing blood HDL cholesterol levels. However, fibrates
are not effective in lowering LDL cholesterol. Examples of fibrates available in
the United Sates include Gemfibrozil (Lopid) and fenofibrate (Tricor).
Very high triglyceride levels (usually > 1000 mg/dl) can cause pancreatitis
(inflammation of the pancreas that can result in a serious an illness with
severe abdominal pain). By lowering the blood triglycerdes, fibrates are used to
prevent pancreatitis.
Fibrates are not effective in lowering LDL cholesterol and cannot be used
alone in lowering LDL cholesterol levels. However, when a high risk patient (see
NCEP recommendations above) also has high blood triglyceride or low HDL
cholesterol levels, doctors may consider combining a fibrate, such as
fenofibrate (Tricor), with a statin. Such a combination will not only lower the
LDL cholesterol, but will also lower blood triglycerides and increase HDL
cholesterol levels.
Fibrates have also been used alone to prevent heart attacks especially in
patients with elevated blood triglycerides and low HDL cholesterol levels. In
one large study, gemfibrozil decreased the risk of heart attacks but did not
affect the overall survival of persons with high cholesterol levels.
What are the side effects of fibrates?
The side effects of fibrates include nausea, stomach upset, and sometimes
diarrhea. Fibrates can also cause liver irritation. The liver irritation is
usually mild and reversible, but it occasionally can be severe enough to require
stopping the drug.
Fibrates can cause gallstones when used over several years.
The fibrates can increase the effectiveness of blood thinners, such as
Coumadin, when both medications are used together. Thus, the dose of Coumadin
should be adjusted to avoid over-thinning of the blood, which can lead to
excessive bleeding.
Fibrates can cause muscle damage. Doctors generally avoid combining a statin
with gemfibrozil because of concern over the added risk of muscle damage with
the combination. Gemfibrozl interferes with the breakdown of statin, resulting
in higher statin blood levels, and hence a higher likelihood of muscle toxicity.
Fenofibrate does not interfere with the breakdown of a statin, and should be the
safer fibrate to use whenever a fibrate-statin combination is necessary.
Furthermore, pravastatin seems to have fewer muscle toxic effects than the other
statins when combined with a fibrate.
Next: What are bile acid sequestrants? »
- Statins - Read about statins, cholesterol lowering medications like Levacor, Zocor, Pravachol, Lipitor, Crestor, and more. Side effects, drug interactions, and patient information is also provided.
- Electrocardiogram (ECG or EKG) - Read about the Electrocardiogram (ECG, EKG) procedure used to reflect underlying heart conditions such as agnina, occurance of a prior heart attack or of an evolving heart attack, and more.
- Heart Attack - Overview on heart attack (myocardial infarction) and heart attack symptoms including jaw pain, headache, shortness of breath, nausea, vomiting, heartburn, sweating, and more.
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