Home HealthTopics Health Centers Reference Library Research
Join us on Facebook Join us on Facebook Share on Facebook

Pharmacy and Medications

Frequency of Lipitor



My doctor prescibed Lipitor 10 MG for for cholesterol control but told me to take one every other day. Is this a safe way to take Lipitor? Previously I was taking one pill per day.


Lipitor (atorvastatin) is a HMG-CoA reductase inhibitor (also known as a "statin") used to treat high cholesterol. The usual dose of atorvastatin is 0.5 - 1 tablet once daily, depending on the cholesterol level and the cost of the medicine. Lately, some doctors have begun recommending that patients take atorvastatin every other day.

Many medicines are removed from the body by being broken down or metabolized by the liver. The amount of time it takes to remove half of the medicine is called the half life. During the first half life, half of the original amount present is removed (50%). During the second half life, half of what remains is removed or 25% of the original amount. This continues until all of a medicine is removed.

The elimination half-life of atorvastatin in humans is approximately 14 hours. Two days (48 hours) is roughly 3.5 half lives. After 3.5 half lives, about 10% of the original dose of atorvastatin is still present in the body. Importantly, atorvastatin is metabolized to what are known as active metabolites. Both the atorvastatin and its active metabolites work to lower cholesterol. This effect can persist for 40-60 hours.

Every other day dosing is a safe and effective way to take atorvastatin. Ideally, this dosing regimen can provide adequate cholesterol reduction with a reduced risk of side effects and reduced cost. It is slowly becoming more popular. Be sure to continue to monitor your diet and exercise as these are important parts of cholesterol control.

This response was prepared in part by Chris Droege, a PharmD student at the University of Cincinnati College of Pharmacy.

For more information:

Go to the Pharmacy and Medications health topic, where you can:

Response by:

Robert James Goetz, PharmD, DABAT
Assistant Professor of Pharmacy Practice
College of Medicine
University of Cincinnati