HMG-CoA Reductase Inhibitors (Statins)

HMG-CoA reductase inhibitors, also referred to as “statins,” are a family of drugs used to reduce high blood levels of cholesterol and LDL (“bad”) cholesterol, and to a lesser extent, triglycerides. Statins may also increase blood levels of HDL (“good”) cholesterol. These drugs include:

Summary of Interactions with Vitamins, Herbs, and Foods
In some cases, a herb or supplement may appear in more than one category, which may seem contradictory. For clarification, read the full article for details about the summarized interactions.

Beneficial May Be Beneficial: Depletion or interference—The medication may deplete or interfere with the absorption or function of the nutrient. Taking these nutrients may help replenish them.

Co-Enzyme Q10
Beneficial May Be Beneficial: Supportive interaction—Taking these supplements may support or otherwise help your medication work better.

Fish oil

Food (lovastatin)

Psyllium (simvastatin)

Sitostanol
Avoid Avoid: Reduced drug absorption/bioavailability—Avoid these supplements when taking this medication since the supplement may decrease the absorption and/or activity of the medication in the body.

St. John’s wort (lovastatin, simvastatin)
Avoid Avoid: Adverse interaction—Avoid these supplements when taking this medication because taking them together may cause undesirable or dangerous results.

Grapefruit or grapefruit juice

Pomegranate juice*

Red yeast rice
Check Check: Other—Before taking any of these supplements or eating any of these foods with your medication, read this article in full for details.

Vitamin A*

Vitamin B3 (niacin)

Vitamin E*
Side effect reduction/prevention

None known

An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.

Interactions with Dietary Supplements

Co-Enzyme Q10
In patients with high cholesterol, statin therapy results in decreased CoQ10 levels.1 2 3 4 Supplementation with 100 mg per day or 10 mg three times per day of CoQ10 has been shown to prevent reductions in blood levels of CoQ10 due to statin therapy.5 In one study, people taking CoQ10 along with simvastatin increased their blood CoQ10 concentration by 63%. Many doctors recommend that people taking HMG-CoA reductase inhibitor drugs also supplement with approximately 100 mg of CoQ10 per day, although lower amounts, such as 10 to 30 mg per day, might be effective in preventing the decline in CoQ10 levels.

Fish oil (EPA)
The omega-3 fatty acid EPA in fish oil may improve the cholesterol- and triglyceride-lowering effect of simvastatin. In a preliminary trial, people with high cholesterol who had been taking simvastatin for about three years were able to significantly lower their triglyceride levels and raise their levels of HDL (“good”) cholesterol by supplementing with either 900 mg or 1,800 mg of EPA per day for three months in addition to simvastatin.6 The authors of the study concluded that the combination of simvastatin and EPA may prevent coronary heart disease better than simvastatin alone.

Sitostanol
A synthetic molecule related to beta-sitosterol, sitostanol, is available in a special margarine and has been shown to lower cholesterol levels. In one study, supplementing with 1.8 grams of sitostanol per day for six weeks enhanced the cholesterol-lowering effect of various statin drugs.7

Vitamin B3 (niacin)
Niacin is the form of vitamin B3 used to lower cholesterol and triglyceride levels. Taking large amounts of niacin along with HMG-CoA reductase inhibitors may cause muscle disorders (myopathy) that can become serious (rhabdomyolysis).8 9 Such problems appear to be uncommon.10 11 Moreover, concurrent use of niacin has been reported to enhance the cholesterol-lowering effect of HMG-CoA reductase inhibitors.12 13 People taking statins should consult a doctor before taking niacin.

Vitamin A
A study of 37 people with high cholesterol treated with diet and HMG-CoA reductase inhibitors found blood vitamin A levels increased over two years of therapy.14 Until more is known, people taking HMG-CoA reductase inhibitors should have blood levels of vitamin A monitored if they intend to supplement with vitamin A.

Vitamin E
In a study of seven patients with high serum cholesterol, eight weeks of simvastatin plus vitamin E 300 IU per day improved markers of blood vessel elasticity more than simvastatin alone.15 Improved blood vessel elasticity reduces the risk for cardiovascular damage and death. Additional controlled studies are necessary to determine whether supplementation with vitamin E enhances the beneficial effects of other statin drugs.

Interactions with Herbs

Psyllium
In one study, supplementing with 15 grams of psyllium per day for eight weeks enhanced the cholesterol-lowering effect of simvastatin.16 Further research is needed to determine whether this result applies to other statins.

Red yeast rice
A supplement containing red yeast rice (Monascus purpureas) has been shown to effectively lower cholesterol and triglycerides in people with moderately elevated levels of these blood lipids.17 However, red yeast rice contains small amounts of naturally occurring HMG-CoA reductase inhibitors and the use of red yeast rice in combination with a statin drug might increase the adverse effects of the drug. For that reason, red yeast rice should not be used if you are currently taking a statin medication.

St. John’s wort
Taking St. John’s wort (Hypericum perforatum) along with lovastatin or simvastatin may lower blood levels of the drug, resulting in decreased effectiveness.18 People taking either of these statin drugs should not take St. John’s wort without the supervision of a doctor.

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Interactions with Foods and Other Compounds

Grapefruit or grapefruit juice
Grapefruit contains substances that may inhibit the body’s ability to break down statins; consuming grapefruit or grapefruit juice might therefore increase the potential toxicity of these drugs. In a study of healthy volunteers, ingesting 200 ml of grapefruit juice along with simvastatin increased blood levels of the drug, compared with taking simvastatin with water.19 There is one case report of a woman developing severe muscle damage from simvastatin after she began eating one grapefruit per day.20 People taking HMG-CoA reductase inhibitors should not eat grapefruit or drink grapefruit juice.

Pomegranate juice
Pomegranate juice has been shown to inhibit the same enzyme that is inhibited by grapefruit juice.21 22 The degree of inhibition is about the same for each of these juices. Therefore, it would be reasonable to expect that pomegranate juice might interact with statin drugs in the same way that grapefruit juice does.

Food
Though the absorption of most statins is not affected by taking the drug with food, blood levels of lovastatin are increased.23 Consequently, lovastatin should be taken with a meal.

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References
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