Effect of short surgical procedures on salivary paracetamol elimination.

The effect of short surgical procedures on paracetamol elimination was studied in seven male patients undergoing surgery with epidural anaesthesia. Five healthy volunteers who did not undergo surgery served as a control group. Paracetamol concentration was measured in saliva at various intervals 1 day before and after surgery. Paracetamol half-life (t1/2,z) decreased and metabolic clearance rate (CL) increased after surgery as compared to preoperative values. The results suggest that surgical stress may enhance the hepatic metabolism of paracetamol.