ZK 93426

ZK-93426 (ethyl-5-isopropoxy-4-methyl-beta-carboline-3-carboxylate) is a drug from the beta-carboline family. It acts as a weak partial inverse agonist of benzodiazepine receptors, meaning that it causes the opposite effects to the benzodiazepine class of drugs and has anxiogenic properties, although unlike most benzodiazepine antagonists it is not a convulsant and actually has weak anticonvulsant effects. In human tests it produced alertness, restlessness and feelings of apprehension, and reversed the effect of the benzodiazepine lormetazepam. It was also shown to produce nootropic effects and increased release of acetylcholine.