A 50-year-old man being treated for increased serum LDL concentration has muscle pain that has recently become more severe, especially with exercise. He is most likely to be taking a drug with which of the following mechanisms of action?
1.Binding bile acids
2.Decreasing binding of bile acids
3.Decreasing production of LDL
4.Decreasing the activity of lipoprotein lipase
5.Inhibiting the activity of 3-hydroxy-3-methylglutaryl (HMG) CoA reductase
Correct answer
Inhibiting the activity of 3-hydroxy-3-methylglutaryl (HMG) CoA reductase
Explanation
This patient is most likely taking a statin. Statins inhibit the activity of HMG CoA reductase (choice E). One of the major side effects reported from statin use is myalgia. This is an important presenting symptom because continued use can result in rhabdomyolysis and acute renal failure. Decreasing the production of LDL (choice C) is an effect of statins, but not the direct action.
Bile acid binding resins (choice A) such as cholestyramine do not cause myalgias.
Decreasing the binding of bile acids (choice B) and decreasing the activity of lipoprotein lipase (choice D) are not current methods for lowering serum cholesterol.