Effect of experimental spinal cord injury on salicylate bioavailability after oral aspirin administration

The purpose of the present work was to study whether spinal cord injury (SC I) alters salicylate bioavailability after oral aspirin administration. Fem ale Sprague-Dawley rats were subjected to SCI at the Ts level by two proced ures, contusion by the weight-drop method and severance by knife, and recei ved a single oral aspirin dose (15 mg/kg) 24 h after injury. Blood samples were drawn and aspirin (ASA) and salicylic acid (SA) concentrations in whol e blood were determined at selected times over a period of 240 min. Both SC I procedures produced similar alterations on salicylate bioavailability. AS A bioavailability was not significantly changed by SCI. On the other hand, SA peak concentrations were significantly reduced in 20% to 30%, compared w ith sham-lesioned controls. The area under the SA concentration against tim e curve was decreased in 10% to 25%, although this difference did not reach statistical significance. Results suggest that SCI at the T8 level decreas es the rate, but not the extent, of aspirin absorption from the gastrointes tinal tract. SCI-induced alterations in aspirin absorption appeared to be m odest compared with those previously reported for other analgesic agents, s uch as paracetamol (acetaminophen). (C) 2000 Elsevier Science Inc. All righ ts reserved.