• CAM-summaries
  • Alternative medical systems
  • Biologically-based practices
  • Diet & nutrition
    • Breuss cancer cure
    • Carctol
    • Co-enzyme Q10
      • What is Co-enzyme Q10?
      • How well does Co-enzyme Q10 work?
      • Is Co-enzyme Q10 safe?
      • Co-enzyme Q10 conclusions
    • Gerson diet
    • Green tea for prevention
    • Lacto-ovo vegetarian diet
    • Megamin
  • Energy medicine
  • Manipulative & body-based practices
  • Mind-body medicine
• CAM systematic reviews
• CAM and the law
• Prevalence of CAM use

Is Co-enzyme Q10 safe?

Documented side effects include: nausea, upper abdominal pain, rashes, dizziness, sensitivity to light, irritability, fatigue, headache, heartburn (ref 26, 27). In doses over 100mg, if taken in the evening, Coenzyme Q10 may cause mild insomnia (ref 28) as it may raise energy levels six to eight hours after being taken. Coenzyme Q10 is contraindicated for pregnant or lactating women (ref 29), those with diabetes and high blood pressure (ref 4). Also, excessive exercise should be avoided whilst taking Coenzyme Q10 (ref 29). Quality and composition of CoQ10 products may differ between manufacturers (ref 30, 31).

Known drug interactions

Theoretically, as CoQ10 has antioxidant properties, and as several chemotherapeutic agents and radiotherapy work using "oxidative stress" (the opposite of antioxidant action), taking CoQ10 may limit the effectiveness of these therapies (ref 7,32).

CoQ10 may increase the risk of blood clotting or bleeding, and therefore may possibly interfere with warfarin (ref 32). However, according Engelsen (ref 33) , CoQ10 and ginkgo biloba do not influence the clinical effect of warfarin Natural levels of CoQ10 may possibly be depleted when taking drugs that lower cholesterol (statins) or blood sugar levels (ref 7, 24, 34) and also beta blockers (ref 7,28)

References

4. Ernster, L, & Forsmark-Andrée, P. Ubiquinol: an endogenous antioxidant in aerobic organisms. Clinical Investigator. 1993; 71 (8 Suppl): S60-5.
7. Jellin, JM., (Ed). Natural Medicines Comprehensive Database. 2003; Stockton, California: Therapeutic Research Faculty.
24. Thibault, A, Samid, D, Tompkins, AC, Figg, WD, Cooper, MR, Hohl, RJ, Trepel, J, Liang, B, Patronas, N, Venzon, DJ, Reed, E, & Myers, CE. Phase 1 study of lovastatin, an inhibitor of the mevalonate pathway, in patients with cancer. Clinical Cancer Research. 1996; 2: 483-91.
26. Baggio, E, Gandini, R, Plancher, AC, Passeri, M, & Carmosino, G. Italian multicenter study on the safety and efficacy of coenzyme Q10 as adjunctive therapy in heart failure. CoQ10 Drug Surveillance Investigators. Molecular Aspects of Medicine. 1994; 15 (Suppl): s287-94.
27. Feigin, A, Kieburtz, K, Como, P, Hickey, C, Claude, K, Abwender, D, Zimmerman, C, Steinberg, K, & Shoulson, I. Assessment of coenzyme Q10 tolerability in Huntington's disease. Movement Disorders. 1996; 11 (3): 321-3.
28. Pepping, J. Coenzyme Q10. American Journal of Health System-Pharmacy. 1999; 56 (6): 519-21.
29. Ernst, E. (Ed). The Desktop Guide to Complementary and Alternative Medicine. An Evidence-Based Approach. 2001; Mosby, London.
30. Overvad, K, Diamant, B, Holm, L, Holmer, G, Mortensen, SA, & Stender, S. Coenzyme Q10 in health and disease. European Journal of Clinical Nutrition. 1999; 53 (10): 764-70.
31. ConsumerLab: Product review: Coenzyme Q10.. [online]. 2005 [cited 2005 Feb 21]. Available from: URL http://www.consumerlab.com/results/coq10.asp
32. Borek, C. Dietary antioxidants and human cancer. Integrative Cancer Therapies. 2004; 3 (4), 333-341.
33. Engelsen J, Nielsen JD, Hansen KF. Effect of Coenzyme Q10 and Ginkgo biloba on warfarin dosage in patients on long-term warfarin treatment. A randomized, double-blind, placebo-controlled cross-over trial. Ugeskr Laeger. 2003, 28 ;165(18):1868-71.
34. Kaikkonen, J, Nyyssonen, K, Tuomainen, TP, Ristonmaa, U, & Salonen, JT. Determinants of plasma coenzyme Q10 in humans. FEBS Letters. 1999; 443 (2): 163-6.