Friday, March 14, 2014

Researchers pronouncing ‘statins are safe’ are undermined by their own observations - Briffa

Researchers pronouncing ‘statins are safe’ are undermined by their own observations

Listen to most ‘key opinion leaders’ talk about statinsand you will hear soothing reassurances about their safety. Yet, my experience as a doctor suggests that adverse effects such as fatigue and muscle pain occur more commonly than ‘official statistics’ suggest. However, a study published this week claims to provide evidence that, for the most part, statin side effects are ‘imagined’ [1].

In this research, the adverse effect rates from statins was compared with those seen in individuals taking placebo (dummy) pills in a total of 29 studies. The conclusion was that apart from increasing the risk of diabetes, statins don’t generally have any more adverse effects than placebo. The actual words the authors use in their conclusion are: “Only a small minority of symptoms reported on statins are genuinely due to the statins: almost all would occur just as frequently on placebo.”

This is confident, seemingly ‘evidence-based’ stuff, indeed. However, these findings do appear to me to be at odds with what I and many other doctors observe in real life: that a significant number of people who take statins have side-effects that resolve (sometimes slowly) on discontinuation of their medication. Of course, as the authors of this most recent study allude to, these side-effects may be nothing more than a negative placebo response – sometimes referred to a ‘nocebo’ response.
However, is there anything about the way statin trials may be designed and conducted that could jeopardise our ability to get accurate data on the adverse effects of these drugs?

Several explanations are possible. First, commercial sponsors of clinical trials may not be motivated to search exhaustively for potential side effects. One pointer towards this is that, although evidence of liver damage is documented in the majority of trials, diabetes diagnoses were only documented in three of the 29 trials assessed in the recent study.

Second, many trials do not state clearly how and how often adverse effects were assessed. Because of this, it far from certain that all adverse events were ‘caught’ and logged appropriately.

Third, some trials’ exclude patients with severe diabetes, kidney failure or high blood pressure. In reality, though, these individuals may come to be prescribed and take statins.

Fourth, trial volunteers tend to be enthusiastic, and may therefore be less likely to report side effects than patients in routine clinical practice.

Fifth, many trials have a ‘run-in’ period where individuals are given a placebo to help ensure adequate compliance with medication. This can cause studies to be ‘enriched’ with highly motivated individuals who, again, may be less likely to complain of side-effects.

Finally, many trials excluded patients on medication sharing the same liver metabolic pathway as statins (e.g. fibrates and macrolide antibiotics). Patients on such drugs, in the real world, might well suffer higher rates of pharmacologically mediated effects.

I make no secret of the fact that I think the benefits of statins are over-hyped and that the adverse effects are generally downplayed. As a result, a cynical observer might read my reservations here and think ‘well, he would say that’.

But, here the kicker: those six issues I detail above were plucked from the very same study that trumpets the safety of statin [1]. Much of what is written in this section of the post was actually lifted verbatim from the study.

So, by the authors’ own admission, there are many reasons why the adverse effect rates seen in statin studies may not accurately reflect the rates seen in the real world. But then how can the authors conclude that: “Only a small minority of symptoms reported on statins are genuinely due to the statins: almost all would occur just as frequently on placebo.”

The reality is the deficiencies of the studies do not allow the authors (or anyone) to conclude that at all. The authors’ pronouncement on safety is utterly undermined by their own admissions about the incompleteness and untrustworthiness of the study data.

The opening line of the study is this: “Patients and doctors need clear reliable information
about benefits and risks to make informed decisions.” The only clear thing about the risks of statins, to my mind, is that there isn’t much clarity. Making bold pronouncements on the safety of statins without us having the facts is potentially misleading, and may cause many to come to considerable harm, needlessly.

1. Finegold JA, et al. What proportion of symptomatic side effects in patients taking statins are genuinely caused by the drug? Systematic review of randomized placebo-controlled trials to aid individual patient choice. European Journal of Preventive Cardiology March 12, 2014

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