Many medications cause dangerous interactions with other drugs when taken together, but, in some cases, things you eat and drink may also pose a threat. An example of this is the combination of grapefruit juice and the prescription cholesterol medication Lipitor or atorvastatin calcium.

Background

Your liver is responsible for filtering Lipitor from your bloodstream for elimination from your body, and the organ completes this task with an enzyme known as cytochrome P450 3A4. Grapefruit juice inhibits the actions of cytochrome P450 3A4 and, therefore, can cause levels of Lipitor in your body to build up.

Clinical Evidence

A 2005 study at the Jichi Medical School in Tochigi, Japan, and published in the British Journal of Clinical Pharmacology found patients who drank grapefruit juice each day for four days and then took 20 mg of atorvastatin calcium experienced higher levels of the drug in their bloodstreams than those who drank water.

Features

The risk of interactions between grapefruit juice and Lipitor increases with an increased amount of grapefruit consumptions, such as drinking more than 1.2 liters of the juice per day, explains the U.S. National Library of Medicine.

Risks

A rare but possible side effect of increased Lipitor levels in your body is rhabdomyolysis, a condition that occurs when the muscles break down, posing a risk for kidney failure and even death, warns the U.S. National Library of Medicine. Symptoms of rhabdomyolysis include muscle malaise, fever and muscle pain, tenderness or weakness.

Considerations

Liver dysfunction or other medical conditions may also affect the levels of Lipitor in your body, making it unsafe for you to consume any amount of grapefruit, explains the Mayo Clinic. Talk to your doctor about how much grapefruit or grapefruit juice is safe for you.

Source:

U.S. National Library of Medicine Daily Med: LIPITOR (atorvastatin calcium)

Mayo Clinic.com: Atorvastatin (Oral Route)

Pubmed.gov: Effects of Grapefruit Juice on the Pharmacokinetics of Pitavastatin and Atorvastatin