Blood substitute trials "should be halted"

Clinical trials of hemoglobin-based blood substitutes in eight countries should be halted because of evidence that shows the products significantly increase the risk of heart attacks and deaths, according to letters the US consumer group Public Citizen has sent to health officials in each country. The eight nations - Belgium, the Czech Republic, Greece, the Netherlands, Poland, South Africa, Sweden and the UK - all have clinical trials that are either ongoing or recruiting participants.

A study published recently in The Journal of the American Medical Association found that patients given these hemoglobin-based blood substitutes (HBBS) face a 30% greater risk of death and a 2.7-fold increased chance of heart attack compared to people treated conventionally. The authors from the National Institutes of Health and Public Citizen identified 16 different trials of five different blood substitutes. These were combined by the authors using a statistical technique called meta-analysis.

After the study was published, says Public Citizen, US Food and Drug Administration officials acknowledged that they were concerned about the risks posed by blood substitutes. Currently, such blood substitutes are not approved for use in the USA, although at least one product is cleared outside the country and new clinical trials are being conducted worldwide.