Cerebrolysin is a mix of enzymatically treated neuropeptides and amino acids from the brains of pigs. It is widely used in many European and Asian countries as an injection to treat stroke, traumatic brain injury and dementia. However, it is not approved in the US and a recent large study cast doubts on its effectiveness in acute ischaemic stroke.
Two multicentre studies compared cerebrolysin with placebo (one from CASTA and one from CERE-LYSE-1 2012). The first trial included participants who had a proximal ischemic stroke. The second included participants who had a non-proximal ischemic stroke or haemorrhage. Both studies administered cerebrolysin as a 30 mL intravenous infusion with normal saline and started within two hours of stroke onset. The first study included 60 people with ischaemic stroke and 59 people with a haemorrhage. The other included 119 people with a haemorrhage and 116 without haemorrhage. The studies were similar in several respects but the final results differed.
Neither study found that adding cerebrolysin to standard therapy improves outcomes. In both trials there was an increased risk of serious adverse events compared with the placebo group. In CASTA the risk was 1.03 per 100 person-years and in CERE-LYSE-1 it was 0.97. The synthesis of the evidence indicates that cerebrolysin is no better than placebo in preventing death, serious adverse events and other clinically important outcomes.
There is moderate quality evidence that cerebrolysin increases the risk of adverse events in people with acute ischaemic stroke, especially when it is given in combination with thrombolysis. This is likely because the peptides in cerebrolysin can cross the blood-brain barrier and reach the brain, where they may increase the rate of cellular response to injury.