NAPLEX Question of the Week: Statin Equivalencies

Can you determine equivalent doses of various statins? It is the subject of our question of the week!
NAPLEX Question of the Week: Statin Equivalencies
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JL presents to your community pharmacy with a letter from his insurance company stating that his Lipitor will no longer be covered on his insurance plan starting next year. JL is currently on 10 mg of Lipitor. Which of the following regimens below could you recommend to JL's primary care provider as an equivalent substitute based on intensity? Select all that apply. 

A. Crestor 20 mg

B. Mevacor 40 mg

C. Zocor 20 mg

D. Lescol XL 80 mg

E. Pravachol 20 mg

 

Answers with rationale:

The correct answers are B, C, and D. 

Statins reduce LDL by competitively inhibiting the enzyme HMG-CoA reductase. The amount of LDL reduction classifies statins into low, moderate, or high intensity regimens. Low intensity is an LDL reduction of less than 30%, moderate is between 30-49%, and high is a 50% or greater reduction in LDL. Lipitor 10mg represents a moderate intensity statin. The AHA guidelines provide common statin agents and what classification they fall under depending on the dose given.1 A modified version of these are listed at end of question.   

Converting between statin therapies is important if patients are on brand name medications and insurance companies decide to take it off their formulary. Another reason for converting to a different statin therapy would be due to potential side effects of the drug such as muscle pain or weakness. In this situation, a switch from a lipophilic statin (atorvastatin, simvastatin) to a hydrophilic statin (rosuvastatin, pravastatin) may provide a reduction in muscle pain and increased tolerability. 

Drug

Equivalent Dose (mg) by Intensity LDL reduction

Rosuvastatin (Crestor)

5-10

Atorvastatin (Lipitor)

10-20

Simvastatin (Zocor)

20-40

Lovastatin (Mevacor)

40-80

Pravastatin (Pravachol)

40-80

Fluvastatin (Lescol)

80 (as either immediate release 40mg BID or XL 80mg daily)

 

Naplex Competency Areas Covered:

2.2: Commercial availability; prescription or non-prescription status; rand, generic, or biosimilar names; physical descriptions; or how supplied

3.4: Drug dosing or dosing adjustments; duration of therapy

4.4: Dose conversions

References:

  1. Grundy SM, Stone NJ, Bailey AL, et al. 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol: Executive Summary. Circulation. 2019;139:e1046-1081. 

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