GR-89696 is a drug which acts as a highly selective κ-opioid

Kappa Opioid receptor

The κ-opioid receptor is a protein that in humans is encoded by the OPRK1 gene. The κ-opioid receptor is one of five related receptors that bind opium-like compounds in the brain and are responsible for mediating the effects of these compounds...

 agonist

Agonist

An agonist is a chemical that binds to a receptor of a cell and triggers a response by that cell. Agonists often mimic the action of a naturally occurring substance...

. It shows selective effects in different animal models and it is thought it may be a subtype-selective agonist for the κ₂ subtype. Recent studies have suggested that GR-89696 and related κ₂-selective agonists may be useful for preventing the itching which is a common side effect of conventional opioid

Opioid

An opioid is a psychoactive chemical that works by binding to opioid receptors, which are found principally in the central and peripheral nervous system and the gastrointestinal tract...

 analgesic

Analgesic

An analgesic is any member of the group of drugs used to relieve pain . The word analgesic derives from Greek an- and algos ....

drugs, without the additional side effects of non-selective kappa agonists.