Health Education – Medication for High Cholesterol

Medication for High Cholesterol – What are your options?

By Dr Paul Chiam

Published on Ezyhealth on December 2014

 

There are several medications used in the treatment of high cholesterol (otherwise known as dyslipidemia). As the low density lipoprotein (LDL) or “bad cholesterol” is the main target of treatment, most of these drugs act primarily to reduce the LDL. Other drugs act mainly to reduce triglycerides (TG) or to raise the high density lipoprotein (HDL) or “good cholesterol”.

The various medications belong to different drug classes:

  • Statins
  • Bile acid sequestrants
  • Cholesterol absorption inhibitors
  • Fibrates
  • Nicotinic acid (a derivative of the vitamin niacin)
  • Omega oils

1) Statins

How They Work

Statins block an enzyme that is required in the production of LDL, thereby lowering the “bad cholesterol” level in the blood. They are the commonest cholesterol lowering drugs used in the treatment of elevated LDL levels, as this class of drugs has been shown in many large studies to reduce the risk of heart artery blockages, heart attacks and strokes, and also reduce risk of death from any cause. In addition, these drugs are considered quite safe to use and are well tolerated.

What is Available

The available statins are:

Generic Brand Name
Atorvastatin Lipitor
Fluvastatin Lescol
Lovastatin Mevacor
Pravastatin Pravachol
Rosuvastatin Crestor
Simvastatin Zocor

Although there are some differences between the various statins, the effects are mostly similar. The major difference is the potency of the individual drug. For example, 10mg of rosuvastatin is equivalent to 20mg of atorvastatin, which is equivalent to 40mg of simvastatin.

Side Effects

Side effects of statins are generally mild and well tolerated. They include:

  • Mild muscle aches
  • Headaches
  • Fatigue
  • Abdominal discomfort
  • Mild increase in liver enzymes

These symptoms usually resolve spontaneously or may improve when the statin dose is reduced.

More severe side effects are rare and require use of the statin to be stopped. These include:

  • Significant elevation of liver enzymes
  • Severe muscle aches
  • Severe muscle breakdown

Patients who experience these symptoms generally require some other class of cholesterol lowering drug.

2) Bile Acid Sequestrants

How They Work

Bile acid sequestrants bind to bile acids in the intestine and prevent them from being reabsorbed into the blood. The liver then produces more bile to replace the bile that has been lost. Because the body needs cholesterol to make bile, the liver uses up the cholesterol in the blood, which reduces the amount of LDL cholesterol circulating in the blood.

They are now considered a “third line” drug to reduce LDL, and are usually used in combination with a statin or with ezetimibe. The LDL lowering effect of bile acid sequestrants is moderate at best and there is no convincing evidence that bile acid sequestrants reduce cardiovascular events or death.

What is Available

Currently available bile acid sequestrants are:

  • Cholestyramine
  • Colestipol
  • Colesevalam

Side Effects

Major side effects are rare, but the usage of bile acid sequestrants is limited by these common side effects:

  • Abdominal bloating
  • Gas
  • Nausea
  • Constipation

They also should not be taken by patients who have high triglyceride levels as they may worsen the high triglycerides.

3) Cholesterol Absorption Inhibitors

What is Available

There is only one drug in this class – ezetimibe (Ezetrol).

How It Works

Ezetimibe binds to cholesterol in the gut and inhibits the absorption, thus lowering blood cholesterol (LDL) levels. It is most often used together with a statin to produce additional LDL lowering, although it has not been shown to further reduce narrowing of the heart arteries or reduce cardiovascular events. In patients who cannot tolerate a statin, ezetimibe is usually used as the second line agent. The drug is well tolerated and is usually safe to use.

Side Effects

Side effects are uncommon and usually minor, and include:

  • Abdominal discomfort
  • Diarrhoea
  • Headache
  • Fatigue

4) Fibrates

How They Work

This group of drugs activate an enzyme called lipoprotein lipase, reducing triglycerides and raising HDL (good cholesterol), but have little effect on LDL (bad cholesterol). They are currently mainly used to treat patients with very high triglycerides. This is to reduce the risk of pancreatitis, a serious inflammation of the pancreas which is potentially life threatening, resulting from the very high triglyceride levels. These drugs were previously commonly used in patients with heart disease to raise the HDL (good cholesterol) and although they did reduce the risk of cardiovascular events, they did not reduce cardiovascular or all causes of death, and thus are now not used commonly in patients with heart disease unless these patients have a very elevated triglyceride level.

What is Available

The two fibrates available are fenofibrate (Lipanthyl) and gemfibrozil (Lopid).

Side Effects

Minor side effects include:

  • Nausea
  • Headache
  • Mild muscle ache
  • Abdominal discomfort
  • Mild elevation of liver enzymes

Serious side effects are:

  • Severe liver enzyme elevations
  • Severe muscle aches
  • Severe muscle breakdown

The serious side effects can occur especially if fibrates are combined with statin, which is a fairly common treatment strategy. In such cases, only fenofibrate (and not gemfibrozil) should be used in combination with a statin at the lowest possible dose.

5) Nicotinic Acid

How It Works

This is a drug derived from the vitamin niacin (vitamin B3). The actual mechanism whereby nicotinic acid works is not known. It raises HDL (good cholesterol) and lowers LDL (bad cholesterol) and triglycerides.

Despite being the seemingly ideal agent, large studies using nicotinic acid have shown disappointing results. Although blood cholesterol profiles were improved, there were no reductions in cardiovascular events or death. Furthermore, the side effects of the high dose nicotinic acid required limits its use.

Side Effects

Flushing is a common and troublesome side effect and is a major reason the drug is discontinued.

Other side effects include:

  • Muscles aches
  • Headaches
  • Nausea
  • Abdominal discomfort
  • Diarrhoea
  • Liver enzyme elevation
  • May predispose to development or worsening of diabetes.

Thus, this drug is now rarely used.

6) Omega-3 Oils

How They Work

These are considered more as a dietary supplement and are derived from fish oils. They are mainly used to lower triglyceride levels. Although generally safe and well tolerated, there is a lack of evidence that omega-3 oils reduce cardiovascular events.

Side Effects

Side effects are usually mild and include:

  • A fishy taste in the mouth
  • A fishy breath
  • Nausea
  • Abdominal discomfort
  • Loose stools

Overall, statins are the first line drugs used in the treatment of patients with high cholesterol. They are effective and have been shown to reduce cardiovascular events and death in large studies, and are generally well tolerated and safe. Other agents are usually added on to a statin as directed by the physician. In rare patients who cannot tolerate a statin, an alternative drug may be considered.