title: Bi- or multifunctional opioid peptide drugs.
abstract: Strategies for the design of bi- or multifunctional drugs are reviewed. A distinction is made between bifunctional drugs interacting in a monovalent fashion with two targets and ligands containing two distinct pharmacophores binding in a bivalent mode to the two binding sites in a receptor heterodimer. Arguments are presented to indicate that some of the so-called "bivalent" ligands reported in the literature are unlikely to simultaneously interact with two binding sites. Aspects related to the development of bi- or multifunctional drugs are illustrated with examples from the field of opioid analgesics. The drug-like properties of the tetrapeptide Dmt(1)[DALDA] with triple action as a micro opioid agonist, norepinephrine uptake inhibitor and releaser of endogenous opioid peptides to produce potent spinal analgesia are reviewed. Rationales for the development of opioid peptides with mixed agonist/antagonist profiles as analgesics with reduced side effects are presented. Progress in the development of mixed micro opioid agonist/delta opioid antagonists with low propensity to produce tolerance and physical dependence is reviewed. Efforts to develop bifunctional peptides containing a micro opioid agonist and a cholecystokinin antagonist or an NK1 receptor antagonist as analgesics expected to produce less tolerance and dependence are also reviewed. A strategy to improve the drug-like properties of bifunctional opioid peptide analgesics is presented.
authors.affiliation: Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montreal, 110 Pine Avenue West, Montreal, Quebec, Canada H2W 1R7. schillp@ircm.qc.ca
authors.forename: Peter W
authors.initials: PW
authors.lastname: Schiller
mesh_terms: D000701:Analgesics, Opioid / Q000009:adverse effects / Q000494:pharmacology*; D000818:Animals; D001665:Binding Sites; D015195:Drug Design; D006801:Humans; D008024:Ligands; D009292:Narcotic Antagonists / Q000009:adverse effects / Q000494:pharmacology*; D010146:Pain / Q000188:drug therapy / Q000503:physiopathology; D017465:Receptors, Opioid, delta / Q000037:antagonists & inhibitors; D017450:Receptors, Opioid, mu / Q000819:agonists
chemical_list: D000701:Analgesics, Opioid; D008024:Ligands; D009292:Narcotic Antagonists; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu