cy 208-243

CY 208-243 is a synthetic indolophenanthridine compound that functions primarily as a **selective dopamine D1 receptor partial agonist** with central nervous system activity. It displays high affinity for dopamine D1 receptors, modest affinity for opioid receptors and 5-HT1A receptor sites, and is known for its **atypical opioid antinociceptive** and **dopaminomimetic** properties. Unlike other D1-selective agonists, CY 208-243 demonstrated **antiparkinsonian effects** in animal models and limited clinical studies, with notable improvement in symptoms such as tremor. Its antinociceptive (analgesic) effect is morphine-like in potency but distinct pharmacologically, lacking typical opioid side effects such as dependence or respiratory depression. The drug did not proceed to late clinical development, and studies were discontinued for safety reasons. CY 208-243 was developed and researched principally by Sandoz Pharma, now part of Novartis.