KarXT is a combination of xanomeline and trospium chloride Karuna is developing as a main treatment and an add-on for psychosis associated with schizophrenia as well as for cognitive and so-called negative symptoms of the disorder. Xanomeline was previously cast off by Eli Lilly after tests in Alzheimer's disease and schizophrenia turned up side effects. Karuna believes adding trospium chloride to the formula will block the pathway that allowed xanomeline to wreak havoc on the gut, causing nausea, diarrhea and increased sweating and salivating. The therapy is currently in phase 3 clinical trials.