Prescription Drugs for Cholesterol and Triglycerides

An important part of preventing atherosclerosis, coronary artery disease (CAD), strokes and peripheral artery disease, is to keep your cholesterol and triglyceride levels from getting too high. While some people can accomplish this goal with diet and exercise, many cannot. If diet and exercise are not enough for you, or if your risk for cardiovascular disease is particularly elevated, chances are that your doctor will want you to begin taking prescription medication. 

Over the years, several kinds of drugs have been prescribed for treating cholesterol and triglycerides. While statins have become the most important class of cholesterol-lowering drugs, many of the older medications are still being used. Furthermore, new kinds of drugs for treating blood lipids are beginning to come into clinical use.

Whatever treatment has been prescribed for you, you should know something about the specific drugs you are taking. Here is a general description of prescription medications available for treating blood lipids.

Statins are the mainstay of therapy for cholesterol, for a very simple reason — statins are the only class of cholesterol-lowering drugs that have been demonstrated to improve the actual outcomes in people with elevated cardiovascular risk, and especially in people who have already had a heart attack or stroke.

The statin drugs inhibit an enzyme called HMG-CoA reductase, which reduces the liver’s ability to make cholesterol. So the statins substantially and reliably lower total blood cholesterol and LDL cholesterol levels.

Statins also reduce vascular inflammation, decrease vascular thrombosis, and improve overall vascular function.

Statins are usually well-tolerated, but side effects do occur. The most notable side effect is muscle pain or weakness, which is seen in 5 - 10% of patients who take these drugs.

Currently available statins include:

• Lipitor (atorvastatin)
• Lescol (fluvastatin)
• Mevacor (lovastatin)
• Livalo  (pitavastatin)
• Pravachol (pravastatin)
• Zocor (simvastatin)
• Crestor (rosuvastatin)

The PCSK9 inhibitors are a new class of cholesterol-lowering drugs. The first two — Repatha (evolocumab) and Praluent (alirocumab) — were approved by the FDA in late 2015. These drugs work by inhibiting the PCSK9 enzyme in the liver, which causes the liver to remove much more LDL cholesterol from the circulation. The PCSK9 inhibitors, which are given by injection, can drive LDL cholesterol to very low levels, and, for this reason, they have generated a lot of enthusiasm among researchers.

Today these drugs are used in patients with familial hypercholesterolemia, or who also have LDL cholesterol levels that remain very elevated despite treatment with statins. Their usage may well expand over the next several years as we learn whether they can improve clinical outcomes, in addition to cholesterol levels — and whether they produce long-term side effects.

Nicotinic acid, a form of niacin, reduces LDL cholesterol and increases HDL cholesterol levels. In the recent past, it was prescribed fairly frequently to increase HDL levels. However, a major clinical study has cast much doubt on the benefits of nicotinic acid. In this study, not only did nicotinic acid fail to improve clinical outcomes but also it may have increased the risk of stroke. Today, nicotinic acid generally is used only for patients with high LDL cholesterol levels who cannot take other drugs.

Ezetimibe reduces the absorption of cholesterol from the intestines, causing the liver to get more of the cholesterol it needs by removing it from the bloodstream. As a result, LDL cholesterol levels are reduced.

Clinical trials with ezetimibe (sold as Vytorin, and in combination with simvastatin as Zetia) have been fairly disappointing, and the drug is not used very often in clinical practice. It is used mainly in people with continued high cholesterol levels despite statin therapy, or who are unable to take statins.

Bile acid sequestrants prevent the reabsorption of cholesterol-containing bile acids from the intestine. This causes the liver to remove more cholesterol from the circulation. The bile acid sequestrants are Questran (cholestyramine), Cholestid (colestipol), and Welchol (colesevelam).

While these drugs also effectively reduce LDL cholesterol levels, they tend to cause gastrointestinal side effects that limit their usefulness. Also, like most other cholesterol-lowering drugs, clinical studies have failed to show that they improve outcomes.

You can read more information on cholestyramine, the most commonly used bile acid sequestrant.

The fibrates — Antara (gemfibrozil) and Lopid (fenofibrate) — are most effective at reducing triglyceride blood levels (by up to 50%). They also increase HDL cholesterol levels and reduce LDL cholesterol levels to some extent. The fibrates work by inhibiting the production of triglyceride-rich lipoproteins in the liver. Once again, however, despite their favorable effect on blood lipids, several randomized trials have failed to show any improvement in clinical outcomes with the fibrates.

The main use of fibrates today is to treat patients with severe hypertriglyceridemia. The most prominent side effect of fibrates is that they can cause muscle toxicity, especially when used with statins.

While several classes of drugs have been shown to have a favorable effect on cholesterol and triglyceride levels, only the statins have been shown to significantly improve clinical outcomes. Current guidelines on treating cholesterol limit their recommendations to the statin drugs — the other drugs are not recommended except in individualized cases.

However, researchers eagerly await the results of clinical trials now being conducted with the PCSK9 inhibitors, a new class of drugs that has an unprecedented cholesterol-lowering effect.