People who regularly take cocaine cut with the animal anti-worming agent levamisole demonstrate impaired cognitive performance and a thinned prefrontal cortex. These findings from two recent studies at the University of Zurich indicate that levamisole could have a toxic effect on the brain. Drug-checking programs should, therefore, be expanded, argue the researchers.
Cocaine is the second most commonly consumed illegal substance worldwide after cannabis. The cocaine sold on the streets is usually cut with other substances such as local anesthetic agents, painkillers and caffeine. Around 10 years ago, however, a new adulterant made an appearance which is now widely spread in street cocaine in Europe and North America: The animal anti-worming agent levamisole. It’s not fully understood why levamisole is added to cocaine, but it is assumed that it may increase or prolong the effects of cocaine.
What is known is that levamisole can lead to severe side effects such as changes to blood counts and blood vessels. Initial animal testing also revealed that the substance can attack the nervous system. A team of researchers from the Psychiatric Hospital and the Institute of Forensic Medicine of the University of Zurich have now researched the extent to which the common cutting agent impairs the cognitive performance and alters the brain structure of people who consume it, thereby increasing the well-described negative effects of cocaine on the brain.