Lipitor is a drug commonly-prescribed for patients with high cholesterol. It is a member of a wider family of cholesterol-lowering "statin" medicines. Grapefruit juice and several other citrus foods have been found to interfere with the natural metabolism of statin drugs including Lipitor. It is important to speak with your doctor regarding Lipitor side effects, and the possible risks of eating grapefruit while taking Lipitor.
Grapefruit
Grapefruit is a popular citrus fruit commonly enjoyed as a breakfast food, dessert and fruit juice. Grapefruit is high in potassium, vitamin C and fiber. In addition to its nutrient content, grapefruits contain hundreds of natural chemicals, some of which can interfere with the body's processing of medications at several stages in the metabolic process.
Lipitor and the Statins
Lipitor, generically known as atorvastatin, is a member of a class of drugs called statins. These pharmaceuticals help reduce dangerously high cholesterol levels and improve blood vessel health through several mechanisms. One of the most important of these pathways is their focused interference with the liver processes that produce cholesterol, inhibiting the enzyme, HMG-CoA reductase, that generates a key cholesterol precursor. Lipitor and the other statins can also improve cell health inside blood vessels and reduce harmful inflammation.
Lipitor Side Effects
While Lipitor is well-tolerated by most patients, it can induce side effects, which under certain circumstances can become very serious. Nasal inflammation, joint pain and stomach upset are among the most frequent side effects, affecting an average of between 4 and 8.5 percent of patients, according to the drug's manufacturer, Pfizer.
Other symptoms, however, can indicate a dangerous side effect leading to liver failure, and the destruction of muscle tissue known as rhabdomyolysis. Though rare, this condition can lead to organ damage and even death. Muscle pain or weakness is a key warning signal that this effect may be underway.
Grapefruit and Lipitor
Lipitor is partially metabolized by an intestinal enzyme known as CYP 3A4. This reaction is natural, and reduces the total amount of medication that is absorbed into the bloodstream. Grapefruit inhibits this enzyme's activity, leading to unusually high concentrations of Lipitor entering the blood.
A 2003 study published in the "Journal of Clinical Pharmacology" found that the imbibing of sufficient grapefruit juice inhibits CYP 3A4 activity in both the intestines and liver. Israeli research, published in the "European Journal of Clinical Nutrition" in 2004, found that just one glass of grapefruit juice is sufficient to produce "the maximal magnitude of the interaction" in the intestines.
Lipitor's prescribing information advises that "larger quantities of grapefruit juice" increase the risk of dangerous muscle side effects while taking the medicine.
Obtaining Medical Guidance
The risk of serious Lipitor side effects is raised when taking medicines with similar chemical activity, or any medication or food that interferes with statin metabolism or raises blood concentration of statins
Because grapefruit raises the levels of Lipitor in the blood, it is important to speak to your doctor about the possible need to avoid or minimize grapefruit products, and certain other foods and medications, while taking Lipitor.
References
- Harvard Medical School: Grapefruit and medication: A cautionary note
- Pfizer: Lipitor Prescribing Information
- "European Journal of Clinical Nutrition": Food--drug interaction: grapefruit juice augments drug bioavailability---mechanism, extent and relevance; A Dahan, et al.; 2004
- "Journal of Cellular and Molecular Medicine": Statins: Mechanism of Action and Effects; Camelia Stancu, et al.; 2001
- MayoClinic.com: Grapefruit juice: Beware of dangerous medication interactions
- "Journal of Clinical Pharmacology": Exposure-Dependent Inhibition of Intestinal and Hepatic CYP3A4 In Vivo by Grapefruit Juice; Maria Veronese, MD, et al.; August 2003.
