title: Prolongation of the pharmacologic effect of intrathecal meperidine by the use of a lipid solution of it.
abstract: The possibility of prolonging the effect of intrathecally injected meperidine by the use of a lipid solution was examined in this study. An aqueous solution of 5% meperidine HCl, 250 micrograms/kg, and an equimolar solution of meperidine dissolved in iophendylate (Pantopaque) were injected subarachnoidally in two groups of rabbits (n = 9 in each) with chronically implanted catheters in the subarachnoid space at the level of L7-8. The effect of each injection was assessed by evaluation of the pain threshold in the animal's hind limbs and of the degree of motor blockade produced. The duration of analgesia and of motor blockade were significantly longer when the lipid solution was used. Six of nine animals that received the aqueous solution of 5% meperidine HCl exhibited temporary signs of agitation (i.e., biting of hind limbs). None of the animals given the lipid solution of the drug did. The findings are attributed to the slow release of meperidine from the lipid phase that serves as a drug depot in the cerebrospinal fluid. The approach presented is suggested as a basis for the development of lipid solutions that might prolong the duration of spinal analgesia produced by a single intrathecal injection.
authors.affiliation: Department of Anesthesiology, Rebecca Sieff Hospital, Safed, Israel.
authors.forename: L
authors.initials: L
authors.lastname: Langerman
authors.forename: E
authors.initials: E
authors.lastname: Golomb
authors.forename: S
authors.initials: S
authors.lastname: Benita
mesh_terms: D000818:Animals; D007278:Injections, Spinal; D008297:Male; D008614:Meperidine / Q000008:administration & dosage / Q000627:therapeutic use*; D009043:Motor Activity / Q000187:drug effects; D010146:Pain / Q000517:prevention & control*; D011817:Rabbits; D012996:Solutions
chemical_list: D012996:Solutions; D008614:Meperidine