Prescribing without evidence
In this important column that MediScene launches this month, we will provide vital information to our readers from top experts about the medications being prescribed to them.
This information based on evidence and scientific fact is provided by the Sri Lanka Association of Clinical Pharmacology and Therapeutics (SLACPT), a newly-formed association comprising eminent medical professionals.
The SLACPT is headed by President, Prof. Rohini Fernandopulle, with the Vice President being Prof. Priyadarshani Galappatthy and Secretary, Prof. Shalini Sri Ranganathan. Its President-Elect is Prof. Asita de Silva. These experts as well as members of the SLACPT council are Specialists in Pharmacology, the branch of medicine concerned with the uses, effects and modes of action of drugs.
The SLACPT may be contacted on: office@slacpt.lk
Substances with little or no evidence of efficacy are being prescribed, dispensed, used, advertised and marketed in Sri Lanka.
As such, there is a need to bring out the real evidence – or rather the lack of evidence – about these products by conducting a detailed literature search and publish the findings in a series of articles. This is what the Sri Lanka Association of Clinical Pharmacology and Therapeutics (SLACPT) has launched under the title ‘Prescribing without evidence’ with the hope that this series will be useful to both the prescribers and the consumers.
The first that will be put under the microscope is Coenzyme Q10.
Coenzyme Q10
- Coenzyme Q10 is not a vitamin as the body produces its own supply
- Coenzyme Q10 is found in most cells of the body, with high concentrations in the heart, liver, kidney and pancreas. It seems to have antioxidant properties and functions as a cofactor in multiple metabolic pathways.
- There is no valid evidence to support the therapeutic use of Coenzyme Q10 in any condition.
- Calling Coenzyme Q10 a supplement is misleading terminology
- Dietary supplements are not intended to treat, diagnose, cure or alleviate the effects of diseases.
- The global Coenzyme Q10 market was valued at US$ 370 million in 2018 and is expected to reach US$ 540 million by the end of 2025. Over decades, the Coenzyme Q10 advocates, particularly the vendors, have been recommending it as a panacea for just about anything: They were, in fact, “working hard” to find an “ill” for this “pill”.
- n In general, most of the studies on Coenzyme Q10 have been poorly designed, under powered and had small sample sizes limiting the validity of the results. A study published in 2014 (Q-SYMBIO) claimed that “our results demonstrate that treatment with CoQ10 in addition to standard therapy for patients with moderate to severe heart failure is safe, well tolerated and associated with a reduction in symptoms and major adverse cardiovascular events”.
BUT:
- The trial took over 10 years to complete (2003- 2012)
- Though the planned sample size was 550 (relatively a very small sample size for cardiovascular diseases trials), the trial was closed (N= 420) before reaching the planned sample size as a result of a low recruitment rate.
- Sponsors of this trial included the International Coenzyme Q10 Association (the advocacy organization); Kaneka Corporation of Osaka (the manufacturer); and Pharma Nord (the marketer) which sells products containing Coenzyme Q10.
- An editorial on the Q-SYMBIO study published in the same issue of the Journal summarizes the irony very crisply: “If 1% of the estimated $1 billion annual market for CoQ10 was reinvested into an adequately powered, appropriately designed, academically led trial to demonstrate the efficacy and safety of CoQ10, then perhaps we would have a scientific advance worth being excited about.”
- Coenzyme Q10 has not been shown to be of value in treating cancer. However, it may reduce the risk of heart damage caused by chemotherapy.
- The small amount of evidence currently available suggests that Coenzyme Q10 probably does not have a meaningful effect on blood pressure.
- Though Coenzyme Q10 has been “advocated” as “possibly effective” in preventing migraines, there is no evidence for this claim.
- Although a few small individual studies have produced some varying results, the overall scientific evidence does not support the use of Coenzyme Q10 to prevent or treat statin associated muscle symptoms.
- A major National Institutes of Health (US)-funded study showed that Coenzyme Q10, even in higher-than-usual doses, didn’t improve symptoms in patients with early Parkinson’s disease. A 2017 evaluation of this study and several other smaller studies concluded that Coenzyme Q10 is not helpful for Parkinson’s symptoms.
- Coenzyme Q10 has also been studied for a variety of other conditions including amyotrophic lateral sclerosis (Lou Gehrig’s disease), Down syndrome, Huntington’s disease and male infertility, but the research is too limited for any conclusions to be drawn.
- No statistically significant results achieved in mitochondrial myopathies. Hence, Coenzyme Q10 is not recommended as a treatment.
- Idebenone is a synthetic analogue of Coenzyme Q10. It is licensed for the treatment of visual impairment in adolescent and adult patients with Leber’s Hereditary Optic Neuropathy (a rare genetic disease).
- Adverse effects of Coenzyme Q10 are rare and include nausea, diarrhoea, heartburn and rarely headache, irritability, agitation and dizziness, may reduce insulin requirements in people with diabetes and may enhance or reduce the anticoagulant effect of warfarin, blood count abnormalities, abnormal liver function and hepatitis.
- A recent study published in the Indian Heart Journal (a systematic review of systematic reviews) concluded that the “CoQ10 supplement may be a useful tool for managing patients with heart failure”. However, all seven systematic reviews included in this review had been very critical about the methodology of the primary studies and recommended strongly the necessity for well conducted studies before any valid conclusions can be made.
Conclusion
There is no evidence-based indication for the use of Coenzyme Q10 in clinical practice.