Statins, also known as HMG-CoA reductase inhibitors, lower cholesterol levels by blocking the enzyme HMG Co-A reductase. By doing so, statins block cholesterol production in the body. Statins are the most widely prescribed cholesterol-lowering medications, since they affect every aspect of your cholesterol panel (LDL, HDL, and triglycerides) in a favorable way.
Although there are known drug interactions with statin medications, there is also another non-drug interaction that can have detrimental effects on your cholesterol lowering therapy: grapefruit.
Although eating fruit may seem harmless, drinking a glass of grapefruit juice or eating a grapefruit around the time you take your statin may be deadly.
The Interaction Between Grapefruit and Statins
Grapefruit contains the compound bergamottin, which interacts with certain enzyme systems in the body, such as cytochrome P-450 and P-glycoprotein. These enzyme systems are responsible for breaking down statins, as well as other drugs, into more usable chemicals and transporting them in the body.
When grapefruit juice is consumed at or around the time you take your statin, the components in grapefruit prevent these enzyme systems from breaking down the drug, causing the drug to accumulate in high amounts in the body. This can be very dangerous and can cause a variety of health problems, such as liver damage or a rare condition called rhabdomyolysis (severe muscle and kidney damage).
Are All Statins Affected?
So far, the only statins significantly affected by this interaction are:
- atorvastatin (Lipitor®)
- lovastatin (Mevacor®)
- simvastatin (Zocor®)
- rosuvastatin (Crestor®)
- pravastatin (Pravachol ®)
- fluvastatin (Lescol ®)
- pitavastatin (Livalo ®)
Some scientists think that this may be due to the fact that these statins are not broken down by the same enzymes.
It Just Takes One Drink or One Grapefruit…
If you’re an avid grapefruit consumer, you’re probably wondering how long it takes before you’ll see this adverse effect. Many studies have shown that it only takes one serving of juice to cause the accumulation of statin drugs in the body. Eating one whole grapefruit can also cause the same effect as a single serving.
Therefore, if you are taking simvastatin, atorvastatin, or lovastatin, you may want to avoid consuming grapefruit products while on these medications. Although the studies concerning grapefruit interactions with pravastatin, fluvastatin, pitavastatin, or rosuvastatin were not as significant, it would probably be safe if you did not consume grapefruit a few hours before or after taking this medication---or avoid grapefruit altogether if you are taking other medications that may interact with grapefruit.
If you can’t stop your grapefruit cravings, you may want to talk to your healthcare provider about lowering the dose of your statin. That way, you’ll be able to enjoy your grapefruit and not suffer from the adverse effects it carries.Sources:
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Holtzmann CW, Wiggins BS, Spinler SA. Role of P-glycoprotein in statin drug interactions. Pharmacotherapy. 2006 Nov;26(11):1601-7.
Lilja JJ, Kivisto KT, Neuvonen PJ. Grapefruit juice increases serum concentrations of atorvastatin and has no effect on pravastatin. Clin Pharmacol Ther. 1999 Aug;66(2):118-27.
Vaquero MP, Sanchez Muniz FJ, Redondo SJ et al. Major diet-drug interactions affecting the kinetic characteristics and hypolipidaemic properties of statins. Nutr Hosp 2010;25:193-206.
Ando H, Tsuruoka S, Yanagihara H et al. Effects fo grapefruit juice on the pharmacokinetics of pitavastatin and atorvastatin. Brit J Clin Pharmacol 2005;60:494-497.