Grapefruit chemicals disrupt the enzymes in the small intestine that break down many medications for absorption, including Lipitor, a cholesterol-lowering medication. The disruption in metabolism causes excess medication to build-up in your body, increasing the strength of Lipitor and the risk of adverse drug reactions. The negative interaction of Lipitor and grapefruit applies to all products derived from grapefruit, including fresh, frozen and canned juice as well as mixed drinks containing grapefruit juice.
The chemical compound that causes the interaction between Lipitor and grapefruit is called furanocoumarins. Furanocoumarins interfere with the way Lipitor breaks down in the gastrointestinal tract and affect how the medication works in your body. This interference causes high levels of Lipitor to remain in the body, increasing the risk of dangerous side effects. Altering the time of Lipitor administration and the consumption of grapefruit doesn't change the drug interaction. The consequences of grapefruit's furanocoumarins can continue for many hours, according to the National Institute of Health's Clinical Center. Rhabdomyolysis, a potential serious complication of combining Lipitor and grapefruit, causes deterioration of skeletal muscles.
Lipitor, generically called atorvastatin calcium, treats high cholesterol levels by lowering total cholesterol, LDL and triglycerides and increasing HDL. Side effects may include muscle pain, fever, headache, edema and abdominal pain and can increase if grapefruit is a part of your diet. Lipitor can be taken either with a meal or on an empty stomach. Liver enzyme test results, especially the ALT and AST, may increase when you're on Lipitor.
Other Citrus Fruits
Pomelos, also known as pummelos, and Seville oranges, bitter-tasting oranges found in compotes and marmalades, can cause the same side effects as grapefruit when taken with Lipitor. Regular oranges and orange juice are safe to consume with Lipitor. Tangelos, a combination of tangerine and grapefruit, don't contain furanocoumarins, despite a portion of the end-product including genetic material from grapefruit.
Frequently, when grapefruit becomes a part of the diet, the side effects of a drug-food interaction are noted in those established on Lipitor drug therapy. If grapefruit, Pomelos and Seville oranges are a part of your daily diet, notify your physician before starting therapy with Lipitor, since a lower dose might avert a potential problem. Not all cholesterol-lowering medications interact with grapefruit. Consult your physician or pharmacist about citrus fruit safety and your medications.
- GlobalRPH.com: Drug - Grapefruit Interactions (Review)
- National Institutes of Health; Clinical Center; Drug-Nutrient Interaction Task Force; Important Drug and Food Information; 2003
- Drugs.com: Grapefruit
- United States Department of Agriculture; Tangerine/Grapefruit Hybrids (Tangelos) Do Not Have Furanocoumarins Associated with Grapefruit/Drug Interactions; Wilbur Widmer; May 4, 2005