Enhanced potency of receptor-selective opioids after acute burn injury.
Dose-response curves of three receptor-selective opioids were established in a group of nonburned and a group of burned rats. Morphine (mu-agonist), biphalin (mu- and delta-agonist), and U50488H (kappa-agonist) were administered to each group, and analgesia was measured by tail flick latency testing. Each opioid had a significant increase in potency (i.e., a decrease in ED50 values) in the burned (15% body surface area) compared with the nonburned groups. Moderate doses of each drug (i.e., ED50 doses estimated from nonburned group data) in each case augmented stress-induced analgesia in the burned group. Analgesic doses failed to prevent a significant increase in plasma beta-endorphin and corticosterone after larger surface area (25%) burns. Regardless of receptor specificity, opioid analgesic potency is increased acutely after burn injuries.
Silbert
B S
BS
Department of Anesthesia, Massachusetts General Hospital, Boston 02114.
Lipkowski
A W
AW
Cepeda
M S
MS
Szyfelbein
S K
SK
Osgood
P F
PF
Carr
D B
DB
D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D000698:Analgesia; D000700:Analgesics / Q000008:administration & dosage / Q000627:therapeutic use*; D000818:Animals; D002056:Burns / Q000188:drug therapy*; D003345:Corticosterone / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004745:Enkephalins / Q000008:administration & dosage / Q000627:therapeutic use*; D007275:Injections, Intravenous; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000627:therapeutic use*; D011759:Pyrrolidines / Q000008:administration & dosage / Q000627:therapeutic use*; D051381:Rats; D011919:Rats, Inbred Strains; D001615:beta-Endorphin / Q000097:blood
D000700:Analgesics; D004745:Enkephalins; D011759:Pyrrolidines; D001615:beta-Endorphin; D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D009020:Morphine; C053673:biphalin; D003345:Corticosterone