An Experimental Model for the Study of Pharmacokinetic Alterations Induced by Spinal Cord Injury in the Rat

The purpose of this work was to provide an experimental model for the study of pharmacokinetic alterations induced by spinal cord injury in male and female Wistar rats. Animals were submitted to spinal cord contusion at the T8–T9 level by the weight drop method. A single oral paracetamol dose (100 mg kg⁻¹) was administered 24 h after injury and blood samples were drawn for a period of 240 min. Paracetamol concentration in whole blood was determined and pharmacokinetic parameters were estimated. C_max and AUC were significantly lower in injured animals, compared with sham‐lesioned controls, while differences in t_max and t_1/2 did not reach statistical significance. Changes in oral paracetamol kinetics induced by spinal cord injury followed a similar pattern in males and females. It is concluded that oral paracetamol bioavailability is importantly reduced by spinal cord injury. The contusion procedure here described appears to be an adequate model for the characterization of pharmacokinetic alterations. 1995 Royal Pharmaceutical Society of Great Britain