If you suffer from recurrent problems with your cholesterol levels, your doctor may recommend medication. How will your physician decide what's right for you? When prescribing a medication to regulate your cholesterol levels, your doctor will consider your medical history, age, lifestyle and-most importantly-your specific cholesterol problems. There are two types of cholesterol medication: One that lowers levels of bad LDL cholesterol and one that increases the amount of good HDL cholesterol in the body. Both can result in a reduced risk of heart attacks and strokes. The most commonly prescribed -and most effective-LDL-lowering medications are in a class of drugs called statins. Stains include drugs like atorvastatin calcium, which is more commonly known as Lipitor. Statins work by inhibiting the enzyme HMG-CoA reductase, which controls the rate of cholesterol production in the body. The result is often a decrease in LDL cholesterol by 20 to 60 percent. Statins are usually taken with the evening meal, or at bedtime. These medications are extremely well tolerated and side effects are rare. Another form of medication that lowers LDL cholesterol is bile acid sequestrants, like cholestyramine, which is marketed under the name Questran, and Colestipol, or Colestid. Bile acid sequestrants bind with cholesterol-containing bile acids in the intestine. This causes more bile acid to be released in the stool, lowering LDL cholesterol levels by up to 15 percent. Cholesterol absorption inhibitors, like ezetimibe, or Zeita, work by blocking the absorption of cholesterol from the intestines. These drugs are about as effective as the bile acid sequestrants in lowering LDL cholesterol. Both cholesterol absorption inhibitors and bile acid sequestrants may be more effective at lowering LDL cholesterol when combined with a statin. If low levels of the good cholesterol, HDL, are the problem, your doctor may turn to a medication like niacin, more commonly known as Vitamin B3. The average American diet contains just 15 to 30 milligrams of Vitamin B3 daily. Using niacin for cholesterol, however, involves much higher doses-up to 3 grams per day. Niocin acid is available both as a prescription and as an over-the-counter medication. It can raise HDL cholesterol by up to 35 percent, but even the OTC version should be used under a doctor's supervision. Not all people with high cholesterol require medication. In most cases, your doctor will recommend lifestyle changes, like a low-fat diet, daily exercise and smoking cessation, as a first recourse. However, if your cholesterol levels don't fall with these measures in about three months, your doctor may prescribe one, or a combination, of these medications. Cholesterol medications can be a great defense against high LDL cholesterol and low HDL cholesterol. However, you should always take medications exactly as prescribed by your doctor.