Monaz: Hello, I'm Monaz Mehta, editor in the Cochrane Editorial and Methods department. When someone has an acute ischemic stroke, urgent effective, simple and reliable treatments will reduce their risks of disability or dying from their brain tissue damage. The treatments used vary around the world, and a drug called cerebrolysin is widely used in post-Soviet countries, Eastern Europe, Central and Southeast Asia. In April 2017, the latest update of this review was published by researchers from Kazan Federal University in Russia and Chinara Razzakova, a PhD student from the university interviewed one of the authors, Liliya Eugenevna, for this podcast.

Chinara: Hello Liliya Eugenevna. Could you tell us a little about the topic for this Cochrane Review? 

Liliya Eugenevna: Briefly, it’s about a medicine called cerebrolysin, which is used for people who’ve had an acute ischemic stroke. It’s believed to have neuroprotective and neurotropic properties and is widely used here in Russia, countries of the former Soviet Union, China and elsewhere in Asia. We wanted to examine its potential benefits for people with acute ischemic stroke, and whether there are any harms associated with its use.

Chinara: So, was one of the main reasons for the review the fact that cerebrolysin is used so often for this type of stroke?

Liliya Eugenevna: That was one of the reasons but the main issue as we worked on the review was the drug’s use as a potential neuroprotector. In ischemic stroke, the concept of “neuroprotection” includes the suppression of changes that lead to an influx of calcium ions, activation of the reactive oxygen species or free radicals, and cell necrosis. These ideas have stimulated the development of many potentially “neuroprotective” substances, some of which were shown to be effective in animal studies. However, the evidence from clinical trials in patients continues to be problematic. This led us to try to find out whether cerebrolysin effectively protects the brain from damage and has benefits, or harms, for people who have had an acute ischemic stroke.

Chinara: This seems to be the most important question for this review and perhaps you could tell us what you did to get an answer.

Liliya Eugenevna: We looked for studies in which patients who were receiving a standard treatment regimen for ischemic stroke were randomized to receive either cerebrolysin or a placebo. We then used these studies to investigate the effects on death and adverse events.

Chinara: How much information did you find?

Liliya Eugenevna: We found six randomized trials with a total of approximately 1500 participants. Three of the six trials were large multicentre studies, two were small and one did not provide quantitative information to include in the final meta-analyses. 

Chinara: And what do the trials tell us about the effects of cerebrolysin?

Liliya Eugenevna: When we combined the evidence, we found no benefit of cerebrolysin use. There was no obvious effect on deaths and the data from the three multicentre studies, which reported serious adverse events, showed that cerebrolysin more than doubled the number of people with non-fatal serious adverse events.

Chinara: That does not sound good for cerebrolysin, but do we need a large clinical trial to resolve this issue once and for all?

Liliya Eugenevna: Although high-quality large-scale randomized trials are always necessary for getting reliable information about the potential value of drugs used in acute ischemic stroke, our review has shown that the potential benefit of cerebrolysin is not supported by reliable evidence and we would not recommend its routine use in acute ischemic stroke. We’ve also shown that the use of cerebrolysin is unsafe and, so, if it is going to be tested in future research, this needs to take the form of well-designed randomised trials and include assessments of the risks of serious adverse events.

Chinara: So, to finish, what would you and your co-authors of this review advise for patients with acute ischemic stroke, their relatives, and doctors who treat and care for them?

Liliya Eugenevna: At its simplest, we’d say that cerebrolysin is not the right choice for the treatment of acute ischemic stroke.

Chinara: Thank you.

Monaz: That was Chinara Razzakova and Liliya Eugenevna from Russia's Kazan Federal University, and if you would like to know more about the results of the Cochrane review, you can find it at Cochrane Library dot com. Just go to the website and type "cerebrolysin and stroke" into the search box.