Key message: The effect of atorvastatin on lowering total cholesterol, LDL-cholesterol and triglyceride was proportional to the dose given. HDL-cholesterol was not significantly affected.
Atorvastatin is one of the most commonly prescribed drugs for preventing coronary heart disease. However, it is licensed in a large range of doses and there is uncertainty about the comparative effectiveness of these different doses. Also, there is often discord between clinicians and patients when discussing preventative medicines which give patients no day to day symptomatic benefit. Patients can have valid concerns about increased doses of Atorvastatin as there is a greater likelihood of side-effects and many patients prefer a “less rather than more” approach for their medications.
This new review included 33,504 participants in 254 trials assessing different doses of atorvastatin over a period of 3 to 12 weeks. The doses assessed ranged from 2.5mg to 80mg per day.
What did they find?
- Total cholesterol was reduced 19.5% for 2.5mg, peak reduction was 38.7% for 80mg
- LDL-cholesterol was reduced by 26.2% for 2.5mg and 53.5% for 80mg
- HDL-cholesterol was not significantly affected
- Triglycerides were reduced by 11.6% for 2.5mg and 32.1% for 80mg
- The effect in each case was proportional to the dose
How good was the evidence?
- There was a high risk of bias in many of the papers included, as many were not blinded, had limited sequence generation and allocation concealment
- There was poor reporting of adverse events; therefore it was not possible to ascertain the incidence of adverse events with confidence
- Approximately half of the trials were industry funded; half were funded by Pfizer (the manufacturer of atorvastatin) and half by other manufacturers
- Publication bias was assessed as not significant
This review helps clarify the relationship between the dose of Atorvastatin and the effect it has on cholesterol levels, which will allow for a more factual and open discussion between clinicians and patients about the expected effects of their medication.
Adams SP, Tsang M,Wright JM. Lipid lowering efficacy of atorvastatin. Cochrane Database of Systematic Reviews 2012, Issue 12. Art. No.: CD008226. DOI: 10.1002/14651858.CD008226.pub2.
Editorial by Julian Higgins: Convincing evidence from controlled and uncontrolled studies on the lipid-loweringeffect of a statin. The Cochrane Library. 12 December 2012. http://www.thecochranelibrary.com/details/editorial/3992221/Convincing-evidence-from-controlled-and-uncontrolled-studies-on-the-lipid-loweri.html
Harry was with the UK Cochrane Centre from October 2012 – May 2013, where he undertook a fellowship in systematic reviews. He is currently part way through his Cardiology specialist training within the Oxford Deanery and before this undertook his medical training in London. He is interested evidence based medicine within cardiology, particular in relation to cardiovascular risk in women, imaging and devices.
You can follow Harry on Twitter @harry9bo