First Aid for the USMLE Step 1 Casebook – Statins
A woman rushes her 65-year-old husband into the emergency department after he said he felt crushing chest pain while eating a steak. Blood work is ordered and the physician finds that the man’s cholesterol is very high and that the man most likely had an acute myocardial infarction because of the finding of elevated enzymes. After consultation, the man is put on statins to lower his cholesterol level and told to avoid a fatty diet.
>>>What are statins?
Statins are a class of hypolipidemic agents. They act to lower cholesterol by inhibiting 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase, the rate-limiting enzyme in cholesterol synthesis.
>>>How do statins affect LDL, HDL, and triglyceride levels?
Statins decrease LDL levels greatly. They have been shown to mildly increase HDL levels and to decrease triglycerides as well.
>>>What is the most effective agent for increasing HDL cholesterol levels?
Niacin has been shown to increase HDL better than most other drugs.
>>>What agent is best suited for decreasing triglyceride levels?
A class of drugs known as “fibrates,” including gemfibrozil and clofibrate, has been shown to greatly diminish triglyceride levels.
>>>What are some of the side effects of statins?
Side effects of this class of drugs include myositis and a reversible increase in liver function tests such as alanine aminotransferase and aspartate aminotransferase.
>>>Why is it dangerous to combine statins and fibrates?
This drug combination significantly increases the risk of rhabdomyolysis.
This case study was contributed by Rakesh Razdan Ahuja, class of 2010, Yale University School of Medicine; in association with Le TT, Takiar V, eds: First Aid Cases for the USMLE Step 1. New York: McGraw-Hill, 2009.
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