CI-988
Encyclopedia
CI-988 is a drug which acts as a cholecystokinin antagonist
, selective for the CCKB
subtype. In animal studies it showed anxiolytic
effects and potentiated the analgesic
action of both morphine
and endogenous opioid peptides, as well as preventing the development of tolerance to opioids and reducing symptoms of withdrawal. Consequently it was hoped that it might have clinical applications for the treatment of pain and anxiety in humans, but trial results were disappointing with only minimal therapeutic effects observed even at high doses. The reason for the failure of CI-988 and other CCKB antagonists in humans despite their apparent promise in pre-clinical animal studies is unclear, although poor pharmacokinetic properties of the currently available drugs are a possible explanation, and CCKB antagonists are still being researched for possible uses as adjuvants to boost the activity of other drugs.
Cholecystokinin antagonist
A Cholecystokinin antagonist is a specific type of receptor antagonist which blocks the receptor sites for the peptide hormone Cholecystokinin ....
, selective for the CCKB
Cholecystokinin B receptor
The cholecystokinin B receptor also known as CCKBR or CCK2 is a protein that in humans is encoded by the CCKBR gene.This gene encodes a G protein-coupled receptor for gastrin and cholecystokinin , regulatory peptides of the brain and gastrointestinal tract...
subtype. In animal studies it showed anxiolytic
Anxiolytic
An anxiolytic is a drug used for the treatment of anxiety, and its related psychological and physical symptoms...
effects and potentiated the 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 ....
action of both morphine
Morphine
Morphine is a potent opiate analgesic medication and is considered to be the prototypical opioid. It was first isolated in 1804 by Friedrich Sertürner, first distributed by same in 1817, and first commercially sold by Merck in 1827, which at the time was a single small chemists' shop. It was more...
and endogenous opioid peptides, as well as preventing the development of tolerance to opioids and reducing symptoms of withdrawal. Consequently it was hoped that it might have clinical applications for the treatment of pain and anxiety in humans, but trial results were disappointing with only minimal therapeutic effects observed even at high doses. The reason for the failure of CI-988 and other CCKB antagonists in humans despite their apparent promise in pre-clinical animal studies is unclear, although poor pharmacokinetic properties of the currently available drugs are a possible explanation, and CCKB antagonists are still being researched for possible uses as adjuvants to boost the activity of other drugs.