The opioid peptide analogue biphalin induces less physical dependence than morphine.
We compared the physical dependence liability of biphalin, a dimeric enkephalin analogue that possesses high antinociceptive activity, with that of morphine in equipotent intravenous doses. Naloxone challenge produced severe withdrawal signs after a 5-day infusion of morphine but only minor withdrawal signs after a 5-day biphalin infusion. In a cross-dependence study, biphalin did not suppress body weight loss after morphine withdrawal, but successfully suppressed weight loss after pentazocine withdrawal. These data support consideration of biphalin as a new analgesic with a novel pharmacological profile and minimum dependence liability.
Yamazaki
M
M
Intensive Care Unit, Toyama Medical and Pharmaceutical University Hospital, Sugitani, Toyama, Japan.
Suzuki
T
T
Narita
M
M
Lipkowski
A W
AW
D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004745:Enkephalins / Q000008:administration & dosage*; D007262:Infusions, Intravenous; D008297:Male; D009020:Morphine / Q000008:administration & dosage*; D009021:Morphine Dependence / Q000209:etiology*; D009270:Naloxone / Q000494:pharmacology; D010423:Pentazocine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D019966:Substance-Related Disorders / Q000209:etiology*; D015431:Weight Loss / Q000187:drug effects
D000701:Analgesics, Opioid; D004745:Enkephalins; D009270:Naloxone; D009020:Morphine; C053673:biphalin; D010423:Pentazocine