On 2017 Jul 08, David Keller commented:

Why Physicians Favored Lipitor Over Simvastatin

In their commentary on generic drug use, Alldredge and Kayser state the following:

"In 2011, fewer prescriptions for generic simvastatin were written than for Lipitor (atorvastatin calcium; Pfizer Inc) despite a significant cost differential and no apparent clinical differences in efficacy and safety." [1]

That statement is an unfair criticism of physicians and conflicts with the expressed views of the Food and Drug Administration (FDA). On June 8, 2011, the FDA issued a safety warning concerning simvastatin [2] in which physicians were advised to discontinue the use of simvastatin, 80 mg (except in patients who had already been taking it safely for over 1 year).

For patients taking amlodipine, the FDA warned against prescribing more than 20 mg of simvastatin, and for patients taking diltiazem or verapamil, the dose of simvastatin was limited to 10 mg. These safety warnings were based on reports of adverse events including serious myopathy caused by simvastatin, 80 mg, and by lower doses of simvastatin when combined with widely prescribed calcium channel blockers.

As a result, physicians were left with a maximum safe simvastatin dose of 40 mg, which lowers low-density lipoprotein cholesterol level by approximately 40%, whereas atorvastatin, 80 mg, lowers low-density lipoprotein cholesterol level by approximately 55%.[3] The FDA has not deemed it necessary to issue similar safety restrictions on the use of atorvastatin, which may explain why physicians favored Lipitor over generic simvastatin in 2011.

References

1: Alldredge BK, Kayser SR. Bending the curve toward increased use of generic drugs. JAMA Intern Med. 2013;173(3):233-234. PubMed Article

2: FDA Drug Safety Communication: new restrictions, contraindications, and dose limitations for Zocor (simvastatin) to reduce the risk of muscle injury. www.fda.gov/Drugs/DrugSafety/ucm256581.htm. Accessed February 21, 2013.

3: Law MR, Wald NJ, Rudnicka AR. Quantifying effect of statins on low density lipoprotein cholesterol, ischaemic heart disease, and stroke: systematic review and meta-analysis. BMJ. 2003;326(7404):1423. PubMed Article

Author's note: the format of the above letter is scrambled and difficult to read, as published online at the following URL:

https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/1726968

Due to the difficulty of getting the published version corrected, I have posted the corrected version above.

On 2017 Jul 08, David Keller commented:

Why Physicians Favored Lipitor Over Simvastatin

In their commentary on generic drug use, Alldredge and Kayser state the following:

"In 2011, fewer prescriptions for generic simvastatin were written than for Lipitor (atorvastatin calcium; Pfizer Inc) despite a significant cost differential and no apparent clinical differences in efficacy and safety." [1]

That statement is an unfair criticism of physicians and conflicts with the expressed views of the Food and Drug Administration (FDA). On June 8, 2011, the FDA issued a safety warning concerning simvastatin [2] in which physicians were advised to discontinue the use of simvastatin, 80 mg (except in patients who had already been taking it safely for over 1 year).

For patients taking amlodipine, the FDA warned against prescribing more than 20 mg of simvastatin, and for patients taking diltiazem or verapamil, the dose of simvastatin was limited to 10 mg. These safety warnings were based on reports of adverse events including serious myopathy caused by simvastatin, 80 mg, and by lower doses of simvastatin when combined with widely prescribed calcium channel blockers.

As a result, physicians were left with a maximum safe simvastatin dose of 40 mg, which lowers low-density lipoprotein cholesterol level by approximately 40%, whereas atorvastatin, 80 mg, lowers low-density lipoprotein cholesterol level by approximately 55%.[3] The FDA has not deemed it necessary to issue similar safety restrictions on the use of atorvastatin, which may explain why physicians favored Lipitor over generic simvastatin in 2011.

References

1: Alldredge BK, Kayser SR. Bending the curve toward increased use of generic drugs. JAMA Intern Med. 2013;173(3):233-234. PubMed Article

2: FDA Drug Safety Communication: new restrictions, contraindications, and dose limitations for Zocor (simvastatin) to reduce the risk of muscle injury. www.fda.gov/Drugs/DrugSafety/ucm256581.htm. Accessed February 21, 2013.

3: Law MR, Wald NJ, Rudnicka AR. Quantifying effect of statins on low density lipoprotein cholesterol, ischaemic heart disease, and stroke: systematic review and meta-analysis. BMJ. 2003;326(7404):1423. PubMed Article

Author's note: the format of the above letter is scrambled and difficult to read, as published online at the following URL:

https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/1726968

Due to the difficulty of getting the published version corrected, I have posted the corrected version above.