Heart Attack and Coenzyme Q10

The supplement coenzyme Q10 (CoQ10) is thought to improve heart function. Research demonstrates that it might help with heart-related problems, such as recurrent heart attacks, congestive heart failure, angina, and arrhythmia.

CoQ 10 taken in combination with the mineral selenium has also shown promise for people who have survived a heart attack.²

The effects of CoQ10 on heart attacks and related conditions are not completely clear. Some evidence suggests that CoQ10 might assist the heart during times of stress on the heart muscle, perhaps by helping it use energy more efficiently.

Read more details about Coenzyme Q10.

In a double-blind trial, 145 people who had recently experienced a heart attack were given either placebo or 120 mg of CoQ 10 daily for 28 days.¹ The results showed that participants receiving CoQ 10 experienced significantly fewer heart-related problems, such as episodes of angina pectoris or arrhythmia, or recurrent heart attacks.

CoQ 10 taken in combination with the mineral selenium has also shown promise for people who have survived a heart attack.²

The typical recommended dosage of CoQ10 is 30 mg to 300 mg daily; higher daily intakes have been used in some studies. In the study discusses here, patients were given daily doses of 120 mg.

CoQ10 is fat soluble and may be better absorbed when taken in an oil-based soft gel form rather than in a dry form such as tablets and capsules.¹¹ Dividing the total daily dosage up into two or more separate doses may produce higher blood levels.¹² A finely ground up (“nanoparticular”) form of the supplement appears to be much better absorbed than standard CoQ10 products.¹³

• Integrative MD
• Clinical nutritionist or registered dietitian
• Naturopathic doctor

Safety Issues

In general, CoQ 10 appears to be extremely safe. No significant side effects have been found, even in studies that lasted a year. ¹ However, people with severe heart disease should not take CoQ 10 (or any other supplement) except under a doctor's supervision.

As noted above, two studies suggest that CoQ 10 might reduce blood sugar levels in people with diabetes. ² While this could potentially be helpful for treatment of diabetes, it might present a risk as well; people with diabetes who are using CoQ 10 might inadvertently push their blood sugar levels dangerously low. However, another trial in people with diabetes found no effect on blood sugar control. ³ The bottom line: If you have diabetes, make sure to track your blood sugar closely if you start taking CoQ 10 (or, indeed, any herb or supplement).

CoQ 10 chemically resembles vitamin K . Since vitamin K counters the anticoagulant effects of warfarin (Coumadin), it has been suggested that CoQ 10 may have the same effect. ⁴ However, a small, double-blind study found no interaction between CoQ 10 and warfarin. ⁵ Nonetheless, in view of warfarin’s low margin of safety, prudence indicates physician supervision before combining CoQ 10 with warfarin.

CoQ 10 might also interact with reverse transcriptase inhibitors used for treatment of HIV (for example, lamivudine and zidovudine). These medications can cause damage to the mitochondria, the energy-producing subunits of cells, leading in turn to a variety of side effects, including lactic acidosis (a dangerous metabolic derangement), peripheral neuropathy (injury to nerves in the extremities), and lipodystrophy (cosmetically undesirable rearrangement of fat in the body). The supplement CoQ 10 has been tried for minimizing these side effects, but unexpected results occurred. In a double-blind, placebo-controlled study, use of CoQ10 improved general sense of well-being in people with HIV-infection using reverse transcriptase inhibitors; however, for reasons that are unclear, it actually worsened symptoms of peripheral neuropathy. ⁶ For this reason, people with HIV who have peripheral neuropathy symptoms should use CoQ 10 only with caution.

The maximum safe dosages of CoQ 10 for young children, pregnant or nursing women, or those with severe liver or kidney disease have not been determined.

Interactions You Should Know About

You may need more CoQ 10 if you are taking:

• Cholesterol-lowering drugs in the statin family
• Red yeast rice
• Beta-blockers (specifically propranolol metoprolol , and alprenolol )
• Antipsychotic drugs in the phenothiazine family
• Tricyclic antidepressants
• Methyldopa
• Hydrochlorothiazide
• Clonidine
• Hydralazine
• Oral diabetes drugs (especially glyburide, phenformin, and tolazamide)

You should not take CoQ 10 except on a physician's advice if you are taking:

• Coumadin (warfarin)

CoQ 10 might improve general sense of well-being, but worsen peripheral neuropathy symptoms if you are taking:

• Reverse-transcriptase inhibitors (for HIV infection)

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