Send to

Choose Destination
Eur J Pharmacol. 2004 Oct 19;502(3):233-7.

Kappa opioid agonists suppress chloroquine-induced scratching in mice.

Author information

Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA.


Chemotherapy of malaria fever with chloroquine is often associated with generalized pruritus of unknown pathogenesis. This adverse side effect leads to diminished compliance. We report that chloroquine (1.25-40 mg/kg, s.c.) elicits dose-related, compulsive, and vigorous scratching in mice. This frenzied behavior is essentially abolished when the mice are pretreated s.c. or orally with nalfurafine (TRK-820), a centrally penetrating kappa opioid agonist. Peripheral kappa receptors are involved because chloroquine-induced scratching is also antagonized by the peripherally restricted kappa agonist, ICI 204,448: R,S-N-[2-(N-methyl-3,4-dichlorophenylacetamido)-2-(3-carboxyphenyl) ethyl]pyrrolidine. We propose that combination therapy for malaria with chloroquine and a kappa agonist (probably one targeting peripheral receptors) will lead to better treatment compliance because of a reduced incidence of pruritus.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center