CoQ10 used in conjunction with the anticoagulant warfarin may render the blood-thinning drug less effective, resulting in a blood clot that produces symptoms of chest pain, impaired vision or trouble breathing, according to Drugs.com. Diabetics using insulin may experience undesirable blood sugar level fluctuations when using CoQ10, adds Mayo Clinic.
Individuals using blood pressure-lowering medications should use caution because CoQ10 may also lower blood pressure, notes Mayo Clinic. Caution is advised for patients with bleeding disorders; reports show when combined with ginkgo biloba, CoQ10 supplementation can result in bleeding. Because CoQ10 may affect heart rate, patients using medications to stabilize heart rates should consult with their physicians. Similarly, individuals using thyroid medications, such as Synthroid, that may result in unbalanced thyroid levels when used in combination with CoQ10 should seek medical advice.
CoQ10 may have adverse interactions with many other drugs, herbs and supplements, such as antidepressants, L-carnitine, omega-3 fatty acids and herbs used to treat the nervous system, the lungs, the immune system and hormonal herbs, adds Mayo Clinic. Caution is advised when supplementing with CoQ10 in individuals who suffer from migraines, stomach or liver problems, skin and mitochondrial disorders. CoQ10 may have negative consequences when added to the diet in the presence of these conditions, although it is thought to be safe for use in healthy people in doses up to 3,000 milligrams a day.